Search

OBJECTIVE To cohouse cats experimentally infected with Bartonella clarridgeiae (Bc) with naive cats in a flea-free environment or with Ctenocephalides felis, Bartonella henselae (Bh), Mycoplasma haemofelis, and Candidatus Mycoplasma haemominutum to determine which flea could be a vector and to assess whether transmission of the infectious agents could be blocked by fipronil and (S)-methoprene. ANIMALS Specific pathogen-free cats (n = 34). METHODS In experiment 1, Bc was inoculated in 1 cat that was housed with 9 naive cats without C felis. In experiment 2, the 2 cats inoculated with Bc were housed with 6 other cats (2 inoculated with Bh, 2 inoculated with M haemofelis, and 2 inoculated with Candidatus M haemominutum) in the center (enclosure 2) of 3 housing enclosures separated by mesh walls that allow passage of fleas but precludes fighting. C felis were placed only on cats in enclosure 2 (5 times). Cats in enclosures 1 (n = 8) and 2 (8) were untreated, and cats in enclosure 3 (8) were administered fipronil and (S)-methoprene. Blood was collected from all cats for PCR assays for the pathogens. RESULTS None of the cats housed with the cat inoculated with Bc became PCR positive in the absence of C felis. All cats in enclosure 2 became Bc DNA positive. While 2 of 8 cats in enclosure 1 became Bc PCR positive, none of the treated cats in enclosure 3 became infected. CLINICAL RELEVANCE The study demonstrated that C felis can be a vector for Bc. The results support the recommendation that flea control products can reduce the risk of transmission of flea-borne pathogens. [ABSTRACT FROM AUTHOR]

Insect growth regulators, like S-methoprene, are heavily relied upon worldwide for larval mosquito chemical control due to their target specificity and long-lasting effects. In this study, susceptibility to S-methoprene was evaluated in Culex pipiens, a globally important vector species. Populations from 14 sites throughout the Chicago area with a long history of S-methoprene use and two sites with minimal use in Wisconsin were examined. Using a bioassay methodology and probit analyses, LC50 and LC90 values were calculated and compared to a susceptible laboratory strain to develop resistance ratios, then categorized for resistance intensity. The resistance ratios observed required the addition of another category, termed 'extreme' resistance, indicating resistance ratios greater than 100. 'Low' to 'extreme' levels of resistance to S-methoprene were detected throughout Illinois populations, with resistance ratios ranging from 2.33 to 1010.52. Resistance was not detected in populations where S-methoprene pressure has been very limited. These 'extreme' resistance ratios observed have never been documented in a wild vector species mosquito population. The relationships between historical S-methoprene use, resistance detected with laboratory bioassays, and the potential for field product failure remain unclear. However, the profound resistance detected here demonstrates a potential critical threat to protecting public health from mosquito-borne diseases. [ABSTRACT FROM AUTHOR]

A simple, robust and QC (quality control) friendly high performance liquid chromatography (HPLC) method was developed and validated for simultaneous determination of four active pharmaceutical ingredient [namely fipronil, (S)-methoprene, eprinomectin, and praziquantel] and their key degradation products in a broad-spectrum topical finished product. Typical sample of the finished product contains a total of 30-plus peaks of interest. Analytes were separated on a HALO C18 column (150 mm × 4.6 mm i.d., 2.7 µm particle size) with a gradient elution at 50 °C column temperature and 0.6 mL/min flow rate. Detection wavelength of 245 nm is used for praziquantel, eprinomectin and their degradation products, 265 nm for (S)-methoprene and its degradation products and 280 nm for fipronil and its degradation products and for the antioxidant, BHT. Mobile phase of the method is composed of 10 mM potassium phosphate buffer and 1,4- Dioxane (98/2, v/v, pH 5.0) as mobile phase-A, and EtOH/MeOH/MeCN/IPA (86/4/6/4, v/v/v/v) as mobile phase-B. All analytes of interest were adequately separated by this single HPLC method. The stability-indicating capability of the method has been demonstrated by successfully separating the degradation products in the stressed degraded samples of the finished product. Limit of quantitation (LOQ) and limit of detection (LOD) of the method is 0.3% and 0.1% of target analytical concentration for each individual API in the finished product. This method has been demonstrated to be sensitive, robust, specific, accurate and stability-indicating for analysis of the topical drug product containing praziquantel, fipronil, eprinomectin and (S)-methoprene. • First HPLC method for simultaneous determination of fipronil, (S)-methoprene, eprinomectin, praziquantel and impurities. • This method can adequately separate 70-plus peaks in forced degraded samples, indicating very high selectivity. • Each chromatographic parameter was methodically optimized to separate large number of peaks in a shortest run time. • A single HPLC method can determine four APIs and degradants in a single run, enhancing laboratory throughput. [ABSTRACT FROM AUTHOR]

Background: The lesser grain borer, Rhyzopertha dominica is a serious pest of stored grains. Fumigation and contact insecticides play a major role in managing this pest globally. While insects are developing genetic resistance to chemicals, hormonal analogues such as s-methoprene play a key role in reducing general pest pressure as well as managing pest populations that are resistant to fumigants and neurotoxic contact insecticides. However, resistance to s-methoprene has been reported in R. dominica with some reports showing a remarkable high resistance, questioning the use of this compound and other related analogues in grain protection. The current study attempts to identify possible molecular mechanisms that contribute in resistance to s-methoprene in R. dominica. Results: Transcriptome analysis of resistant and susceptible strains of this pest species identified a set of differentially expressed genes related to cytochrome P450s, indicating their potential role in resistance to s-methoprene. Laboratory bioassays were performed with s-methoprene treated wheat grains in presence and absence of piperonyl butoxide (PBO), a cytochrome P450 inhibitor. The results indicate that PBO, when applied alone, at least at the concentration tested here, had no effect on R. dominica adult emergence, but has a clear synergistic effect to s-methoprene. The number of produced progeny decreased in presence of the inhibitor, especially in the resistant strain. In addition, we also identified CYP complement (CYPome) of R. dominica, annotated and analysed phylogenetically, to understand the evolutionary relationships with other species. Conclusions: The information generated in current study suggest that PBO can effectively be used to break resistance to s-methoprene in R. dominica. [ABSTRACT FROM AUTHOR]

A single topical application of a combination of fipronil, (S)-methoprene, pyriproxyfen (Frontline® Gold, Merial, now part of Boehringer Ingelheim) on cats significantly prevented flea egg development (Ctenocephalides felis) in a simulated home environment for 15 weeks. Six healthy male cats were treated and then split in two groups of 3, and each group was housed in separate, identical rooms. For the duration of the study, the cats had free access to three sites in rooms that were covered by a carpet to allow contact with the animals' fur during resting. A portion of the original carpet was retained for use as control carpet. In order to assess the prevention of flea egg development, carpet discs of 48 mm in diameter were sampled on a weekly basis from each carpet, i.e., 6 discs/week, for 15 weeks, and placed into vials with 60 C. felis eggs and flea growth medium and were then incubated for 35 to 37 days. In parallel, six identical discs of carpets without any contact with treated cats were used as untreated controls. During the 15 weeks of the study, an average of 41.0 newly emerged adult fleas (36.5 - 45.3) were recovered weekly from the control carpets, and an average of 2.6 fleas (0.7 - 5.7) were recovered from the carpets in contact with the treated cats. Significantly fewer adults fleas were recovered from the carpets in contact with FRONTLINE Gold treated cats than the control carpets at all time-points (p<0.005). A single administration of FRONTLINE Gold administered topically to cats reduced flea egg development by an average of 93.6% for 15 weeks in this simulated environment. [ABSTRACT FROM AUTHOR]

Background: This controlled laboratory study was designed to evaluate the efficacy of the 10 % imidacloprid/4.5 % flumethrin collar (Seresto®, Bayer Animal Health) against fleas (Ctenocephalides f. felis) on cats, when compared to fipronil (9.8 %w/w)/(s)-methoprene (11.8 % w/w) topical spot-on formulation (Frontline® Plus for Cats and Kittens, Merial). Methods: Thirty cats were randomized into three groups of ten animals based on pre-treatment flea counts: Group 1: imidacloprid/flumethrin collar; Group 2: fipronil/(s)-methoprene topical spot-on and Group 3: non-treated controls. The imidacloprid/flumethrin collars were applied one time on Day 0, while the fipronil/(s)-methoprene spot-on was administered every 30 days from Day 0 through Day 210. Cats were infested with 100 fleas on study days 0, 7, 14, 29, 59, 89, 119, 149, 179, 209 and 239. All flea counts were conducted by combing to remove fleas on post-treatment days 2, 8, 15, 30, 60, 90, 120, 150, 180, 210 and 240. Results: The efficacy of the imidacloprid/flumethrin collar ranged from 98.2 to 100 % for eight months. The efficacy of fipronil/(s)-methoprene spot-on ranged from 68.2 to 99.9 %. Efficacy was < 85 % for fipronil/(s)-methoprene on Days 90, 150 and 210. The flea counts in both treatment groups were significantly fewer than those in the nontreated control group at every post-treatment study day (P < 0.0001). In addition, there were significantly fewer fleas in the imidacloprid/flumethrin collar group when compared to the fipronil/(s)-methoprene group on Days 90, 150 and 210 (P < 0.0001). Conclusions: This study demonstrated that the imidacloprid/flumethrin collar (Seresto®, Bayer Animal Health) maintained excellent ( > 98.2 %) efficacy against fleas on cats for the entire 8 month study. Monthly applications of fipronil/(s)-methoprene (Frontline® Plus for Cats and Kittens, Merial) generally had high, but variable (68.2 to 99.9 %) efficacy over the course of the eight month study. Based on the very high residual efficacy achieved by the imidacloprid/flumethrin collar in this study, veterinarians should expect that this collar will control and eliminate existing flea infestations on cats and in their in-home premises as long as every flea infested host is treated. [ABSTRACT FROM AUTHOR]

Aedes albopictus (Skuse) is a globally significant vector that complexifies management programs already contending with Aedes aegypti (L.). The Ae. albopictus mosquito is a daytime biting, container breeding, anthropophilic mosquito that is generally considered unresponsive to operational larviciding that does not also incorporate source reduction. S-methoprene is a readily available juvenile hormone mimic common to pest management. This 14-week study examines direct and indirect treatment efficacy using s-methoprene as an ultra-low volume (ULV) truck spray in area-wide operations against Ae. albopictus in the southeastern United States. An overall 63.3% reduction of Ae. albopictus adults and 47.8% reduction of deposited eggs in treatment areas were observed compared with control. Indirect plots saw reduction in Ae. albopictus adults by 32.7% and eggs by 32.3%. Using insect growth regulator bioassays, truck-mounted ULV application of s-methoprene was effective to an inhibition of emergence (IE) of ≥92% within directly treated (sprayed) areas and >65% IE among containers placed up to 90 m away. S-methoprene could still benefit urban vector management programs when applied at an operational scale. [ABSTRACT FROM AUTHOR]

Two separate studies were performed to evaluate the 24-hour efficacy of FRONTLINE ® Plus for Dogs (fipronil/(S)-methoprene, Boehringer Ingelheim, Duluth, GA, USA) and FRONTLINE Gold for Dogs (fipronil/(S)-methoprene/pyriproxyfen, Boehringer Ingelheim, Duluth, GA, USA) against Ixodes scapularis ticks on Days 2, 9, 16, 23, and 30. From a pool of 28 dogs, 24 dogs with the highest tick counts were allocated to one of three treatment groups: Group A comprised eight control dogs treated with 0.5 mL of mineral oil each, Group B comprised eight dogs treated with FRONTLINE Plus (0.67 mL for dogs 5 to 22 lbs, or 1.34 mL for dogs 23 to 44 lbs), and Group C comprised eight FRONTLINE Gold-treated dogs (0.67 mL for dogs 5 to 22 lbs, or 1.34 mL for dogs 23 to 44 lbs). The first study compared Groups A and B, and the second study compared Groups A and C. Both studies utilized the same control dogs. Both studies were performed at the same time, on the same days, at the same facility. Combining the two studies, 24 dogs were treated with mineral oil (Group A), FRONTLINE Plus (Group B), or FRONTLINE Gold (Group C) on Day 0. All dogs were infested with 50 live, unfed Ixodes scapularis ticks on Days 1, 8, 15, 22, and 29 post-treatment, and all ticks were removed and counted 24 hours later on Days 2, 9, 16, 23, and 30. Dogs treated with FRONTLINE Plus had significantly (p<0.01) fewer live ticks than the controls at 24 hours post-infestation on Days 2, 9, 16, 23, and 30. Geometric mean efficacy was 100% at Days 9 and 23; >99% at Days 2 and 16; and 93.2% at Day 30. Dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live ticks than the controls at 24 hours post-infestation on Days 2, 9, 16, 23, and 30. Geometric mean efficacy was 100% at Days 9, 16, and 23; >99% at Day 2; and 98.4% at Day 30. Both products demonstrated excellent efficacy and persistent activity against Ixodes scapularis tick infestations at 24 hours for a full 30 days. [ABSTRACT FROM AUTHOR]

Three studies were performed to assess the efficacy, speed of kill, and residual effects of FRONTLINE® Gold for Dogs (fipronil/ (S)-methoprene/pyriproxyfen, Boehringer Ingelheim, Merial, Inc., Duluth, GA) against Ctenocephalides felis fleas. Although temporally separate, all three studies were performed at the same facility, each using eight dogs per treatment group, with two treatment groups in the first two studies and three treatment groups in the third study. In the first study, 16 dogs were infested with 100 unfed adult fleas on Day 2 following treatment, and the fleas were removed and counted 30 minutes later. In the second study, the same dogs were infested with 100 unfed adult fleas on Days 2, 9, 16, 23, and 30 following treatment, and the fleas were removed and counted 12 hours later. In the third study, a group of eight FRONTLINE Plus-treated dogs were included, so 24 total dogs were infested with 100 unfed adult fleas, and the fleas were removed and counted 6 hours later on Days 2, 9, 16, 23, and 30. In the first study, dogs treated with FRONTLINE Gold had significantly (p=0.01) fewer live fleas than the control dogs 30 minutes post-infestation on Day 2. Geometric mean efficacy was 64.8%. In the second study, dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live fleas than the control dogs 12 hours post-infestation on Days 2, 9, 16, 23, and 30. Geometric mean efficacy was 100% on Days 2, 9, 16, and 23, and 99.1% on Day 30. In the third study, dogs treated with FRONTLINE Plus had significantly (p<0.01) fewer live fleas than the control dogs at 6 hours post-infestation on all assessments through Day 23, and significantly (p<0.05) fewer live fleas than the control dogs at six hours post-infestation on Day 30. FRONTLINE Plus Geometric mean efficacy was 99.3%, 100%, 99.0%, 97.4%, and 74.4% on Days 2, 9, 16, 23, and 30, respectively. Dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live fleas than the control dogs at six hours postinfestation on all assessments through Day 30. Geometric mean efficacy was 100%, 100%, 99.5%, 99.9%, and 98.4% on Days 2, 9, 16, 23, and 30, respectively. In this study, dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live fleas than those treated with FRONTLINE Plus on Days 23 and 30. A single dose of FRONTLINE Gold for Dogs (1.34 ml) demonstrated excellent efficacy, speed of kill, and residual effects against Ctenocephalides felis fleas for a full 30 days, and demonstrated better persistent speed of kill and residual effects than FRONTLINE Plus at the six-hour count for a full 30 days. [ABSTRACT FROM AUTHOR]

The efficacy of a novel topical combination of fipronil 8.3% w/v, (S)-methoprene 10% w/v, eprinomectin 0.4% w/v, and praziquantel 8.3% w/v (BROADLINE®, 1 [1] Broadline® is a trademark of Merial; all other marks are the property of their respective owners. Merial) against larval and adult Aelurostrongylus abstrusus lungworms in cats was assessed in a controlled laboratory study. The study included 48 purpose-bred, short-haired cats which were each inoculated with 225 infective A. abstrusus larvae. The cats were formed into eight blocks based on pre-treatment bodyweight and were then, within each block, randomly allocated to one of six treatment groups: untreated control; treated once when A. abstrusus were expected to be third-stage larvae (4 days post inoculation [dpi]), fourth-stage larvae (7dpi), immature adults (14dpi) or adult nematodes (32dpi), or treated twice, once when A. abstrusus were expected to be third-stage larval and once again when A. abstrusus were expected to be adult nematodes (4dpi+32dpi). Cats weighing ≥0.8–2.5kg received one 0.3mL applicator and cats weighing >2.5–7.5kg received one 0.9mL applicator. For determination of the efficacy of treatments, lungworm larval counts were established on faecal samples collected from all cats 32, 39, 46, 53 and 60dpi. At each occasion from 46dpi on, cats treated with fipronil, (S)-methoprene, eprinomectin and praziquantel had significantly lower A. abstrusus larval counts than the untreated controls with percentage reductions of 91.6% (cats treated 14dpi; P =0.012), ≥98.9% (cats treated either 4dpi, 7dpi or 32dpi; P <0.001) or >99.9% (cats treated 4dpi+32dpi; P <0.001) at 60dpi. Thus, the novel topical combination of fipronil, (S)-methoprene, eprinomectin and praziquantel was highly effective in the prevention and treatment of A. abstrusus lungworm infection in cats. [ABSTRACT FROM AUTHOR]

A novel topical combination product (BROADLINEÃ?®, Merial) composed of fipronil, (S)-methoprene, eprinomectin and praziquantel was evaluated for safety and efficacy against nematode and cestode infections in domestic cats. The study comprised a multi-centre, positive control, blinded, field study, using a randomized block design based on order of presentation for allocation. In total 196 client-owned cats, confirmed as positive for naturally acquired infections of nematodes and/or cestodes by pre-treatment faecal examination, were studied in seven countries in Europe. Pre-treatment faecal examination revealed the presence of Toxocara, hookworm, Capillaria and/or spirurid nematode infections in 129, 73, 33 or 1 cat(s), respectively; infections with taeniid and Dipylidium cestodes were demonstrated in 39 and 17 cats, respectively. Cats were allocated randomly to one of two treatments in a ratio of 2, topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINEÃ?®, Merial; 130 cats); and 1, topical PROFENDERÃ?® Spot-On (Bayer; 66 cats) and treated once on Day 0. For evaluation of efficacy, two faecal samples were collected, one prior to treatment (Day −4Ã?±4 days) and one at the end of the study (Day 14Ã?±5 days). These were examined for fecal forms of nematode and cestode parasites. For evaluation of safety, cats were examined by a veterinarian before treatment and at the end of the study, and cat owners recorded the health status of their cats daily until the end of the study. For cats treated with BroadlineÃ?®, the efficacy was >99.9%, 100%, and 99.6% for Toxocara, hookworms, and Capillaria, respectively; and the efficacy was >99.9%, >99.9%, and 98.5%, respectively, for the cats treated with ProfenderÃ?® (p <0.001 for all nematodes and both treatments). Efficacy was 100% for both cestodes for both treatments (p <0.001). No treatment related adverse experiences were observed throughout the study. For both treatments, every cat that completed the study was given a safety score of ‘excellent’ for both local and systemic evaluations. The topical combination product of fipronil, (S)-methoprene, eprinomectin and praziquantel was shown to have an excellent safety profile and demonstrated high levels of efficacy when administered once as topical solution to cats infected with nematodes and cestodes under field conditions. [ABSTRACT FROM AUTHOR]

The efficacy of a novel topical combination of fipronil 8.3% (w/v), (S)-methoprene 10% (w/v), eprinomectin 0.4% (w/v) and praziquantel 8.3% (w/v) (BROADLINE�®) was tested against adult and immature stages of Ctenocephalides felis fleas in six studies. For that purpose, fleas from different colonies from North America, Germany and South Africa were used to induce infestations in cats under laboratory conditions. In each study, between 12 and 16 cats were allocated randomly to 2 groups. Cats in Group 1 were not treated and served as controls. Cats in Group 2 were treated once on Day 0 with BROADLINE�® at the minimum recommended dosage of 0.12mg/kg body weight. In 4 studies, all animals were infested experimentally with unfed C. felis (100�±5) on Days 2 (or 1), 7, 14, 21, 28 and 35. Live fleas were counted 24h post-treatment or infestation. In 2 additional studies, animals were infested at the same frequency with gravid C. felis fleas (100�±5) that were fed previously on an untreated host. Forty-eight hours post-infestation, flea eggs were collected, counted and incubated for the evaluation of the reduction of emergence of adults. The combined curative efficacy against adult fleas at 24h after treatment was 94.3% and the combined preventive efficacy values remained greater than 95.9% at 24h after 5 subsequent weekly infestations. In addition, the product reduced dramatically the emergence of new adult fleas for at least 5 weeks (>98.1% for one month and 93.2% at 5 weeks after infestation), demonstrating its efficiency in preventing environmental contamination by immature stages. [ABSTRACT FROM AUTHOR]

Four studies were conducted to examine the efficacy of a novel topical combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel (BROADLINE�®, Merial) against Ancylostoma tubaeforme and Ancylostoma braziliense hookworms of cats. In each study, purpose-bred cats were randomly assigned to treatment groups of 10 or 12 cats per group. In three studies the cats were inoculated with A. tubaeforme and in one study with A. braziliense. The inoculations were undertaken on a schedule which resulted in the hookworms reaching the fourth larval stage in two of the studies, or the adult stage in four of the studies, by the day of treatment. In each study there was also an untreated control and 1 or 2 groups treated with the novel combination. In the two studies where efficacy against the fourth larval stage of A. tubaeforme was tested, the efficacy recorded was 100%. In the three studies where efficacy against the adult stage of A. tubaeforme was tested, efficacy of 100% was also confirmed. In the study where efficacy against the adult stage of A. braziliense was tested efficacy was 99.5%. [ABSTRACT FROM AUTHOR]

Abstract: Benzophenanthridine alkaloids (chelerythrine and sanguinarine) inhibited binding of [3H]SR141716A to mouse brain membranes (IC50s: <1µM). Piperonyl butoxide and (S)-methoprene were less potent (IC50s: 21 and 63µM respectively). Benzophenanthridines and piperonyl butoxide were more selective towards brain CB1 receptors versus spleen CB2 receptors. All compounds reduced B max of [3H]SR141716A binding to CB1 receptors, but only methoprene and piperonyl butoxide increased K d (3–5-fold). Benzophenanthridines increased the K d of [3H]CP55940 binding (6-fold), but did not alter B max. (S)-methoprene increased the K d of [3H]CP55940 binding (by almost 4-fold) and reduced B max by 60%. Piperonyl butoxide lowered the B max of [3H]CP55940 binding by 50%, but did not influence K d. All compounds reduced [3H]SR141716A and [3H]CP55940 association with CB1 receptors. Combined with a saturating concentration of SR141716A, only piperonyl butoxide and (S)-methoprene increased dissociation of [3H]SR141716A above that of SR141716A alone. Only piperonyl butoxide increased dissociation of [3H]CP55940 to a level greater than CP55940 alone. Binding results indicate predominantly allosteric components to the study compounds action. 4-Aminopyridine-(4-AP-) evoked release of l-glutamate from synaptosomes was partially inhibited by WIN55212-2, an effect completely neutralized by AM251, (S)-methoprene and piperonyl butoxide. With WIN55212-2 present, benzophenanthridines enhanced 4-AP-evoked l-glutamate release above 4-AP alone. Modulatory patterns of l-glutamate release (with WIN-55212-2 present) align with previous antagonist/inverse agonist profiling based on [35S]GTPγS binding. Although these compounds exhibit lower potencies compared to many classical CB1 receptor inhibitors, they may have potential to modify CB1-receptor-dependent behavioral/physiological outcomes in the whole animal. [Copyright &y& Elsevier]

A study was performed to compare the 6-hour efficacy of FRONTLINE® Gold (fipronil/(S)-methoprene/pyriproxyfen) with that of SIMPARICA® (sarolaner) against Ctenocephalides felis flea infestations on dogs. Twenty-four dogs were allocated to one of three groups, eight dogs in each group. On Day 0, each dog in Group B was treated with a dose of commercially available FRONTLINE Gold for dogs appropriate for its weight, and each dog in Group C was treated with a dose of commercially available SIMPARICA appropriate for its weight. Group A dogs remained untreated throughout the duration of the study. On each of Days 1, 7, 14, 21, and 28, all dogs were infested with 100 live, unfed Ctenocephalides felis fleas, and 6 hours later, all fleas were removed and counted. Using arithmetic means for all calculations, dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live fleas than the controls at 6 hours post-infestation on all assessment days from Day 1 to Day 28. FRONTLINE Gold's 6-hour efficacies were 88.8%, 98.2%, 99.2%, 95.2%, and 83.0% on Days 1, 7, 14, 21, and 28, respectively. Dogs treated with SIMPARICA had significantly (p<0.01) fewer live fleas than the controls at 6 hours post-infestation on the same days. SIMPARICA 6-hour efficacies were 100%, 100%, 98.8%, 86.6%, and 87.0% on the same days, respectively. There was no significant (p>0.05) difference in flea count between the dogs treated with FRONTLINE Gold and those treated with SIMPARICA on any of the 6-hour post-infestation assessments. [ABSTRACT FROM AUTHOR]

A study was performed to compare the 12-hour efficacy of FRONTLINE® Gold (fipronil/(S)-methoprene/pyriproxyfen) with that of SIMPARICA® (sarolaner) against Ixodes scapularis tick infestations on dogs. Based on pre-treatment tick count, 24 dogs were allocated to one of three groups, eight dogs in each group. On Day 0, each dog in Group B was treated with a dose of commercially available FRONTLINE Gold for Dogs appropriate for its weight, and each dog in Group C was treated with a dose of commercially available SIMPARICA appropriate for its weight. Group A dogs remained untreated throughout the duration of the study. On each of Days 1, 7, 14, 21, and 28, all dogs were infested with 50 live, unfed Ixodes scapularis ticks, and at 12 hours post-infestation on Days 2, 8, 15, 22, and 29, ticks were removed from all dogs and counted. Using arithmetic means for all calculations, dogs treated with FRONTLINE Gold had significantly (p<0.01) fewer live ticks than the controls at 12 hours post-infestation on all evaluation days from Day 2 to Day 29. FRONTLINE Gold 12-hour arithmetic mean efficacy was 99.1%, 100%, 100%, 100%, and 94.7% on the same days. Dogs treated with SIMPARICA had significantly (p<0.01) fewer live ticks than the controls at 12 hours post-infestation on the same days. SIMPARICA 12-hour arithmetic mean efficacy was 97.0%, 96.1%, 92.6%, 87.3%, and 84.5% on the same days, respectively. Dogs treated with FRONTLINE Gold had significantly (p<0.05) fewer live ticks than dogs treated with SIMPARICA on Day 15. [ABSTRACT FROM AUTHOR]

Abstract: Five laboratory studies were conducted to confirm that a single topical dose of the novel combination of fipronil, amitraz and (S)-methoprene, CERTIFECT™ (Merial Limited, GA, USA), is efficacious for the rapid control of pre-existing infestations and the prevention of new infestations with Ixodes scapularis, Dermacentor variabilis, Amblyomma americanum and Amblyomma maculatum for at least 28 days on dogs. In each study, 8 male and 8 female purpose-bred, laboratory beagles were randomly assigned to one of two study groups (treated and untreated). Starting on the day before treatment, each dog was infested weekly with about 30 or 50 ticks, depending on the study. Treatment with the novel combination rapidly eliminated pre-existing infestations and controlled weekly re-infestations for at least 28 days. Pre-existing infestations with all four tick species were rapidly and effectively reduced, with post-treatment therapeutic efficacies ranging from 91.7 to 99.5% within 18–48h post treatment. Amblyomma maculatum numbers were significantly (p <0.05) reduced on treated dogs from the first tick counts as early as 6h post-treatment. All subsequent infestations with each of the 4 tick species were quickly disrupted, with prophylactic efficacies greater than 90% within 18–48h post-infestation for at least a full month. Because the combination of fipronil, amitraz and (S)-methoprene quickly starts disrupting and killing ixodid ticks within hours of treatment, with similar high levels of efficacy maintained for at least 28 days in these and other studies, the authors conclude that a single topical treatment with CERTIFECT may prevent the transmission of most infectious agents carried by ixodid ticks for at least one month. [Copyright &y& Elsevier]

The inhibitory activities of fipronil (10% (w/v) solution), (S)-methoprene (9% (w/v) solution), and fipronil/(S)-methoprene (10 and 9% (w/v) solution, respectively) combination against eggs and emerging adult cat fleas (Ctenocephalides felis) and adulticidal activity were tested on experimentally infested dogs. Thirty-two Beagle dogs were selected for this study and eight replicates of four animals were formed based on body weight within sex. One dog in each replicate was randomly allocated to treatment with: (1) untreated control; (2) fipronil 10% (w/v) solution, (3) (S)-methoprene 9% (w/v) solution, and (4) fipronil 10% (w/v) and (S)-methoprene 9% (w/v) combination solution. Treatments were applied once topically on Day 0 at the rate of 0.067ml/kg. On Days -12, -1, 21, and weekly to Day 84 each dog was infested with ∼200 fleas and comb counted ∼24h later, or 2 days (our 48h) after in the case of Day -1 infestation. On Days -11, 1, 22, and weekly to Day 85 each dog was again infested with ∼200 fleas. Flea eggs were collected over ∼24h beginning 3 days after infestation. Fleas were combed off of the dogs and counted at the end of the egg collection period (∼96h count). One aliquot of up to about 100 eggs, if available, from each animal at each infestation time was incubated for ∼72h to determine larval hatch and the other for 35 days to determine the number of adults that developed.The 10% (w/v) fipronil spot-on provided excellent control (>95%) of adult fleas on dogs for 5 weeks. Similarly, the combination spot-on of 10% (w/v) fipronil and 9% (w/v) (S)-methoprene provided excellent control of adult fleas, i.e., >95% for 5 weeks. From week 6 post-treatment onward, the relatively low inhibition of adult flea emergence substantiated the lack of significant ovicidal/larvicidal activity in the fipronil (10%, w/v) treatment group. However, the combination product provided excellent (>90%) ovicidal activity for 8 weeks and high (91.4%) inhibition of adult flea emergence for 12 weeks. In addition, a synergistic effect of the two compounds in combination was demonstrated with fipronil enhancing the ovicidal and inhibition of adult flea emergence activity of (S)-methoprene against cat flea eggs.When all stages of the life cycle of the cat flea are considered, the combination spot-on product provided a high level of total flea control yielding a curative effect against adult fleas and inhibition of flea development stages with little to no potential reinfestation pressure on the animal or in the environment for 12 weeks. [Copyright &y& Elsevier]

Background A study was conducted to evaluate the efficacy of FRONTLINE® TRITAK® For Dogs (fipronil/(S)-methoprene/cyphenothrin, Merial, Inc., Duluth, GA) against a known strain of fleas with a history of reduced susceptibility to fipronil and pyrethroids, KS1 (Kansas State 1), of Ctenocephalides felis felis fleas. Methods One day after topical treatment with placebo or active, dogs (n = 32) were infested with 100 unfed adult KS1 fleas, with repeat infestations on Days 7, 14, 21 and 28. The number of live fleas was counted at 12 hours post-infestation for Groups 1 (n=8) and 3 (n=8) and at 24 hours post-infestation for Groups 2 (n=8) and 4 (n=8). Results Observed efficacies were 97.1-99.8% at 12-hour assessments on Day 1 through Day 28 and 99.8-100% at 24-hour assessments, occurring on Day 2 through Day 29. Conclusions A single dose of FRONTLINE® TRITAK® For Dogs (fipronil/(S)-methoprene/cyphenothrin) (0.67 ml or 1.34 ml) provided excellent efficacy against the KS1 Ctenocephalides felis felis flea strain for up to 4 weeks after treatment. [ABSTRACT FROM AUTHOR]

The efficacy of a novel topical combination of fipronil 9.8% (w/v) and (S)-methoprene 8.8% (w/v) (Fiprofort® Plus) was tested against ticks and fleas in naturally infested dogs. A total of fifty dogs were allocated in the study with ticks infestation (n=35) and fleas infestation (n=15). On day 0, thirty-five tick and fifteen flea infested dogs received the test formulation, a combination of fipronil 9.8% (w/v) and (S)-methoprene 8.8% (w/v) spot-on solution. Ticks and flea counts were taken on days 0 (pretreatment) and 3, 7, 14, 21, 28, and 35 after treatment. Blood samples were collected for evaluation of haematological parameters on days 0 (pretreatment) and 7, 21, and 35 after treatment. All the adult ticks and fleas collected were identified as Rhipicephalus sanguineus and Ctenocephalides felis, respectively. The efficacy of spot-on formulation against ticks was 34.00% (day 3), 53.14% (day 7), 62.71% (day 14), 65.48% (day 21), 59.80% (day 28), and 58.82% (day 35), whereas against fleas it was 38.00% (day 3), 64.34% (day 7), 89.67% (day 14), 95.40% (day 21), 100.00% (day 28), and 100.00% (day 35). Haematological parameters for ticks and fleas infested dogs were statistically nonsignificant as compared to control. The combination of fipronil and (S)-methoprene eliminated the existing ticks and fleas infestation and prevented the dogs from flea and tick infestation for four weeks. [ABSTRACT FROM AUTHOR]

Abstract: A novel combination of fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) was evaluated for the prevention of attachment of ticks and its ability to cause detachment of ticks. For the two prevention of attachment studies, 20 purpose-bred beagles were allocated each to two equal groups based on pretreatment tick counts (treated and untreated). Each dog was exposed to 50 adult Rhipicephalus sanguineus and Dermacentor variabilis weekly starting 24h after treatment. In study 1 infestations with R. sanguineus were discontinued after Day 7 but continued to Day 28 for D. variabilis in both studies. Counts of ticks by species were made 2, 4 and 24h after exposure to ticks. Ticks not attaching to dogs were evaluated for viability. For the evaluation of detachment study, 16 purpose-bred beagles were allocated each to two equal groups based on pretreatment tick counts (treated and untreated). Each dog was infested with 50 unfed R. sanguineus and D. variabilis adults on Day -2. Ticks were thumb counted without removal on all dogs on Day -1, and at 4, 12, and 24h after treatment. Ticks were counted and removed at 48h after treatment. Dogs treated with the novel combination had significantly (p <0.05) lower total numbers of attached R. sanguineus and D. variabilis than untreated controls at 4h through Day 7. For R. sanguineus, percent reduction of attachment at 24h after infestation through Day 29 ranged from 94.5% to 100%. For D. variabilis, the percent reduction of attachment at 24h through Day 22 was above 98.0%. These studies demonstrate that novel combination can disrupt attachment of R. sanguineus and D. variabilis for up to 28 days following treatment. Of those ticks that are exposed to the treatment, even if they do not attach to the dog and remain in the environment, greater than 90% (p <0.05) die within 24h for 2–3 weeks following treatment. Also, for those dogs infested with ticks at the time of treatment, the novel combination causes significant detachment (p <.05) starting at 12h and reaching 98.9% by 48h after treatment. This product provides an effective means for controlling ticks infesting dogs and limiting the spread of tick transmitted diseases. Additionally, the mortality of ticks exposed to CERTIFECT will reduce infestation of the dog''s environment. [Copyright &y& Elsevier]

Cats are host to dipylidiid cestodes of the genera Diplopylidium, Dipylidium and Joyeuxiella. Broadline, a topical broad-spectrum combination parasiticide containing fipronil (8.3 % w/ v), (S)-methoprene (10 % w/ v), eprinomectin (0.4 % w/ v) and the cestocide praziquantel (8.3 % w/ v), has previously been shown to be efficacious against Dipylidium caninum and Diplopylidium spp. in cats. To evaluate its efficacy against Joyeuxiella species, a blinded clinical efficacy study was conducted according to GCP. All cats had evidence for naturally acquired dipylidiid cestode infection as confirmed by pre-treatment examination. Cats were allocated randomly to two groups of 13 cats each based on bodyweight: Control (untreated) and Broadline at 0.12 mL/kg bodyweight administered once topically. Based on the comparison of helminth counts in the treated and untreated cats seven days post treatment, Broadline demonstrated >99 % efficacy ( p < 0.01) against mature J. fuhrmanni and J. pasqualei, with 11 and 13 of the untreated cats harbouring 1 to 102 or 2 to 95 cestodes, respectively. In addition, parasite counts indicated 95.9 % efficacy ( p = 0.006) against the rictularoid nematode Pterygodermatites cahirensis. [ABSTRACT FROM AUTHOR]

Background: Efficacy of FRONTLINE® TRITAK® For Dogs (fipronil/(S)-methoprene/cyphenothrin, Merial, Inc., Duluth, GA) against Ixodes scapularis was evaluated in two separate, but concurrent laboratory studies. Methods: One day after topical treatment with placebo or active, dogs (n = 24) were infested with 50 unfed adult Ixodes scapularis ticks, with repeat infestations on Days 7, 14, 21 and 28. The number of live ticks was counted at 6 hours post-infestation in the first study (n = 12) and at 24 hours post-infestation in the second study (n = 12). Results: Observed efficacies in study 1 were 93-99 % at 6 hour assessments on Day 1 through Day 28 and in the second study, 98-100 % at 24 hour assessments, occurring on Day 2 through Day 29. Conclusions: A single dose of FRONTLINE® TRITAK® For Dogs (fipronil/(S)-methoprene/cyphenothrin) (0.67 ml or 1.34 ml) prevented the establishment of a new infestation following treatment, as well as the repeated weekly re-infestations with Ixodes scapularis ticks, for 4 weeks. [ABSTRACT FROM AUTHOR]

Background: Efficacy of FRONTLINE® TRITAK® For Dogs (fipronil/(S)-methoprene/cyphenothrin, Merial, Inc., Duluth, GA) against Ixodes scapularis was evaluated in two separate, but concurrent laboratory studies. Methods: One day after topical treatment with placebo or active, dogs (n = 24) were infested with 50 unfed adult Ixodes scapularis ticks, with repeat infestations on Days 7, 14, 21 and 28. The number of live ticks was counted at 6 hours post-infestation in the first study (n = 12) and at 24 hours post-infestation in the second study (n = 12). Results: Observed efficacies in study 1 were 93-99 % at 6 hour assessments on Day 1 through Day 28 and in the second study, 98-100 % at 24 hour assessments, occurring on Day 2 through Day 29. Conclusions: A single dose of FRONTLINE® TRITAK® For Dogs (fipronil/(S)-methoprene/cyphenothrin) (0.67 ml or 1.34 ml) prevented the establishment of a new infestation following treatment, as well as the repeated weekly re-infestations with Ixodes scapularis ticks, for 4 weeks. [ABSTRACT FROM AUTHOR]

Wasmannia auropunctata Roger (Hymenoptera: Formicidae), little fire ant, is recognized as a serious pest ant species that affects agriculture, homes, gardens, and natural ecosystems in Hawaii, USA, and elsewhere. Anecdotal evidence suggests that insecticidal baits containing (S)-methoprene are not effective against this species. We examined whether W. auropunctata is repelled by bait formulations containing this compound and whether the addition of torula yeast ( Candida utilis Lodder; Saccharomycetales: Saccharomycetaceae) increased palatability of these baits. Wasmannia auropunctata was found to be repelled by (S)-methoprene concentrations as low as 0.25% regardless of formulation. The addition of torula yeast (3% by weight) significantly increased worker recruitment to baits with and without (S)-methoprene. Our results indicate bait formulations using (S)-methoprene are likely to offer poor efficacy against Wasmannia auropunctata without the addition of a feeding stimulant such as torula yeast due to repellency of the active ingredient [ABSTRACT FROM AUTHOR]

The objective of the study was to confirm the acaricidal efficacy of a single topical treatment of the combination of fipronil/ amitraz/(S)-methoprene (CERTIFECT®) against induced infestations of Dermacentor variabilis. Sixteen healthy mixed breed mongrels (8 males and 8 females), approximately 9.6 to 13.7 months of age on Day 0, and weighing 16.2 to 33.4 lbs, were selected from a group of 20 dogs based on Day -1 pre-treatment tick counts to be utilized in this randomized, blinded efficacy study. Eight dogs were randomly assigned to one of the two treatment groups: Group 1- placebo (vehicle), Group 2 - fipronil/ amitraz/(S)-methoprene (delivering at least 6.7mg fipronil/kg body weight (bw), 8.0 mg amitraz/kg bw, and 6.0 mg (S)-methoprene/ kg bw). The vehicle or treatment was applied directly onto the skin at two separate spots on the neck of each dog, once on Day 0, per label dose and directions for use. All dogs were infested with 50 (± 5) unfed adult D. variabilis on Day 1, then weekly on Days 7, 14, 21, 28, and 35. Ticks were thumb counted at 24 (±3) hours following each tick infestation and subsequently were counted and removed from each dog at 48 (±3) hours after tick infestation. Thumb counts were performed on all dogs at 24 hours following each infestation. Efficacies on Days 2, 8, 15, 22, 29, and 36 were 98.6, 100, 99.7, 96.6, 86.6, and 90.1%, respectively. All dogs treated with the fipronil/amitraz/(S)-methoprene product had significantly (p<0.05) fewer ticks than placebo (vehicle-treated) control animals. Removal counts were performed at 48 hours after each infestation. Efficacies for Days 3, 9, 16, 23, 30, and 37 were 100, 100, 100, 100, 99.4, and 97.2%, respectively. Again, all dogs treated with the fipronil/ amitraz/(S)-methoprene product had significantly (p<0.05) fewer ticks than placebo (vehicle-treated) control animals. No treatment related adverse events were observed during the study, including during four observations performed within 5 hours post-treatment. The results of this study confirm rapid and effective control of D. variabilis ticks on CERTIFECT-treated dogs [ABSTRACT FROM AUTHOR]

Abstract: This field trial was designed to test the efficacy, in terms of treatment and prevention, of the fipronil 10%+(S)-methoprene 9% combination against immature and adult stages of Rhipicephalus sanguineus in naturally infested dogs, and to assess the effect of a single plain water exposure. Twenty-four dogs of various age, sex, weight and coat length were divided into two homogeneous groups, treated (T) and control (C), and housed into twin outdoor kennels. Trial baseline was designed as day 0, when dogs from group T were treated with a commercial spot-on formulation of fipronil 10%+(S)-methoprene 9%, while subjects from group C were left untreated and served as control. After treatment, tick load for each included dog was estimated, for both adult and immature ticks, using the localization and count over the entire body surface at the following time-points: day 2, to evaluate the speed of kill and at days 7, 14, 21 and 28 to assess the persistence of efficacy. The effect of water exposure on the product efficacy was tested at day 14 of the study, when six dogs, homogenously selected from group T, were soaked through with plain water. The overall tick load in dogs from group C was high throughout the entire study period, ranging from 103.2 (day 28) to 161.3 (day 0), and confirmed the high tick pressure. Speed of kill calculated at 48h post-treatment was slightly higher for adult ticks (96.2%) than for immature stages (91.6%). Compared to the control, dogs treated with the fipronil+(S)-methoprene maintained a significantly lower mean tick load for both adult and immature stages in the four weeks of observation. Persistence of efficacy against immature stages ranged from 97.1% the first week, 99.6% second week, 99.7 third week and 93.1% in the last week. In the same way, efficacy against adult ticks was constantly high, shifting from 94.5% to 92.5%. Overall efficacy (adults+immatures) was the strongest in the first two weeks (i.e., 96.1% and 96.6%) and lowered in the two remaining weeks (i.e., 94.2% and 93.4%). Results showed that water exposure did not affect the activity and persistence of the tested combination. On the basis of this field trial, the fipronil+(S)-methoprene combination represents a highly efficacious product to control all stages of R. sanguineus ticks on dogs. [Copyright &y& Elsevier]

The efficacy of a novel topical fipronil, (S)-methoprene, eprinomectin and praziquantel combination product (BROADLINEÃ?®, Merial) was evaluated against adult Toxascaris leonina ascarids in experimentally infected cats in two controlled studies under an identical protocol. For each study, 30 nematode-naive, purpose-bred European Short Hair cats were inoculated orally with approximately 300 larvated T. leonina eggs. Twenty-two and 24 cats, respectively, that were shown to be positive for Toxascaris eggs by pre-treatment faecal examination were subsequently included in the two studies. In each study, the animals were allocated randomly to an untreated (control) group or to a treatment group. The treatment was a novel topical combination: fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4% w/v) and praziquantel (8.3% w/v). Treatment was applied on Day 0 at 0.12mL/kg bodyweight. For parasite recovery and count, cats were euthanized humanely seven days after treatment and necropsied. All untreated cats harboured adult T. leonina (range, 1–31 nematodes). The treatment provided a high level of efficacy against adult T. leonina in both studies (95.8% and 98.1%, respectively p <0.001). All cats accepted the treatment well based on hourly post-treatment observations for 4h and daily observations thereafter. No adverse experiences or other health problems were observed throughout the studies. Thus the data indicate that this novel combination product will provide a safe and effective treatment against T. leonina in cats. [ABSTRACT FROM AUTHOR]

Although foxes are the main reservoir of Echinococcus multilocularis, it is recognized that dogs and cats also may become infected. In cats the infection and egg production rates are usually low. Nevertheless, cats are a potential source of transmission of E. multilocularis. Due to the high human medical significance of E. multilocularis infection, it is important in endemic areas that owned cats are dewormed regularly. This paper presents the efficacy results of a new topical formulation, BroadlineÃƁfÁâ?C5;!Ãâ?šÃ?® (Merial) tested against E. multilocularis infection in cats. Two blinded laboratory studies were conducted to evaluate this novel topical combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel against E. multilocularis. In each study, purpose-bred cats were assigned randomly to two treatment groups of 10 cats each: one untreated control group and one group treated at the minimum therapeutic dose of 0.12mL/kg bodyweight to deliver 10mg fipronil, 12mg (S)-methoprene, 0.5mg eprinomectin and 10mg praziquantel/kg bodyweight. The cats were inoculated orally with E. multilocularis protoscolices, 22 or 23 days before treatment. Based on necropsy and intestinal worm count, 8 or 11 days after treatment, the two studies confirmed 100% efficacy of BroadlineÃƁfÁâ?ÊÅ!Ãâ?šÃ?® against adult E. multilocularis. [ABSTRACT FROM AUTHOR]

Abstract: The efficacy of a novel topical combination formulation of fipronil, (S)-methoprene, eprinomectin and praziquantel against naturally acquired intestinal nematode and cestode infections in cats was evaluated in seven negative control, blinded studies. Cats were selected based on a pre-treatment faecal examination indicating a patent infection with at least hookworms (two studies), Toxocara ascarids (one study), taeniid cestodes (two studies) or Dipylidium cestodes (two studies). In each study, cats were assigned randomly to blocks of two animals each, based on decreasing pre-treatment body weight and were randomly allocated to one of two groups of six to 12 cats: untreated (control) or treated with topical fipronil (8.3%, w/v), (S)-methoprene (10%, w/v), eprinomectin (0.4%, w/v) and praziquantel (8.3%, w/v) (BROADLINE®, Merial) at 0.12mL/kg body weight (providing a minimum of 10mg fipronil+12mg S-methoprene+0.5mg eprinomectin+10mg praziquantel per kg body weight). The topical treatment was administered directly on the skin in the midline of the neck in a single spot once on Day 0. For parasite recovery and count, cats were euthanized humanely and necropsied seven or ten days after treatment. A single treatment with the novel topical combination product provided 91% efficacy against Ancylostoma braziliense, ≥99% efficacy against Ancylostoma tubaeforme, and >97% efficacy against Toxocara cati. Similarly, excellent efficacy was established against Taenia taeniaeformis, Dipylidium caninum and Diplopylidium spp. as demonstrated by >97% and up to 100% reductions of cestode counts in the treated cats when compared to the untreated controls (P <0.01). All cats accepted the treatment well based on health observations post-treatment and daily health observations. No adverse experiences or other health problems were observed throughout the studies. The results of this series of controlled studies demonstrated high efficacy and excellent acceptability of the novel topical combination formulation of fipronil, (S)-methoprene, eprinomectin and praziquantel against a broad range of feline intestinal nematode and cestode infections. [Copyright &y& Elsevier]

Background A recently launched topical ectoparasiticide containing fipronil, amitraz and S-methoprene has been associated with the development of an acantholytic pustular dermatitis similar to that of Promeris-triggered pemphigus foliaceus ( PF). Hypothesis/Objectives Our objectives were to describe the clinical, histological and immunological features of this PF-like cutaneous adverse drug reaction. Animals Twenty-one dogs with a probable or definitive diagnosis of PF-like cutaneous adverse drug reaction were identified between May 2012 and February 2013. Material and Methods Histology, direct and indirect immunofluorescence were employed to address the study objectives. Results Most dogs were middle-aged or older (median, 9 years) and of large size (median, 23 kg). In six dogs (29%), the PF-like lesions remained confined to the site of application, while 15 dogs (71%) exhibited lesions at distant sites. One or two applications of the ectoparasiticide were sufficient to trigger PF-like lesions in seven (33%) and six (29%) dogs, respectively. Systemic signs were reported in nine dogs (43%), all with lesions extending to sites distant from application areas. Tissue-bound antikeratinocyte IgG was detected in the lesional epidermis of eight of 19 (42%) cases by direct immunofluorescence, while serum antikeratinocyte IgG was detected in 10 of 14 (71%) cases by indirect immunofluorescence. Autoantibodies were found to target canine desmocollin-1 in 11 of 14 dogs (79%), but not canine desmoglein-1, by indirect immunofluorescence on transfected cells. These immunological findings were similar in cases with localized and distant disease. Conclusions and clinical importance This new topical ectoparasiticide containing fipronil, amitraz and S-methoprene is capable of triggering the development of an acantholytic pustular dermatosis that is a clinical, histological and immunological close match for Promeris-triggered PF and naturally occurring autoimmune PF in dogs. [ABSTRACT FROM AUTHOR]

Abstract: The ability of CERTIFECT® (a combination of fipronil, amitraz and (S)-methoprene) to prevent transmission of Ehrlichia canis was studied in two groups of eight dogs. One group was treated with CERTIFECT while the other group remained untreated. All dogs were exposed to E. canis-infected Rhipicephalus sanguineus ticks on Days 7, 14, 21 and again on day 28 post-treatment by releasing ticks into the kennels of the dogs to simulate the natural way of infestation. Animals were examined in situ for ticks on Days 9, 16 and 23 and any ticks present were counted and removed on Day 30. The efficacy of CERTIFECT against R. sanguineus was 100%, since no ticks were found on the treated dogs at any time. Clinical examinations (including monitoring body temperature and blood collections for PCR analysis and serology) were performed at intervals throughout the study until Day 56. Five out of 8 untreated control dogs (62.5%) became infected with E. canis, as demonstrated by detection of specific E. canis antibodies and the presence of E. canis DNA in blood samples by PCR. These dogs displayed fever and thrombocytopenia and were rescue-treated with doxycline. None of the 8 dogs treated with CERTIFECT became infected with E. canis, in comparison to the 5/8 control dogs, as confirmed by the lack of specific antibodies and absence of any ehrlichial DNA in blood samples by PCR. CERTIFECT prevented transmission of E. canis and effectively provided protection against monocytic ehrlichiose for at least 4 weeks post treatment. [Copyright &y& Elsevier]

Abstract: A novel spot-on formulation combining fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) was evaluated in adult Beagle dogs in a study to determine its adulticidal efficacy against the dog flea (Ctenocephalides canis, Curtis, 1826). Sixteen dogs were randomly allocated to treatment groups: 8 dogs served as untreated controls, and 8 dogs were treated once. Treatment consisted of applying a new combination formulation to deliver at least 6.7mg fipronil/kg body weight (bw), 8.0mg amitraz/kgbw, and 6.0mg (S)-methoprene/kgbw. The combination was designed to enhance the efficacy against ticks of the original fipronil/(S)-methoprene combination. Each dog was infested with 100 adult unfed dog fleas within 24h prior to treatment and then at weekly intervals for 8 weeks after treatment. At 24h after treatment or after each subsequent infestation, each dog was combed thoroughly to remove live fleas to be counted. A single treatment with CERTIFECT provided excellent knock-down of fleas within 24h after treatment and controlled re-infestations for up to 7 weeks (efficacy ≥96.5%, p <0.05). [Copyright &y& Elsevier]

Infection with urinary capillarid bladder worms has been observed in cats worldwide. Although considered as generally causing no or little harm, infection with urinary capillarids may be associated with clinical disease which requires an appropriate treatment including the use of anthelmintics. Therefore, the efficacy of a novel topical combination formulation of fipronil 8.3% (w/v), (S)-methoprene 10% (w/v), eprinomectin 0.4% (w/v), and praziquantel 8.3% (w/v) (BROADLINEÃâ?šÃ?®, Merial) was evaluated against urinary capillarids in naturally infected cats. Sixteen European Short Hair cats (5 male, 11 female) with capillarid eggs in their urine pre-treatment were included in the study. At the time of treatment, the cats were approximately ten months to eight years old and weighed 1.6–3.6kg. Cats were ranked based on decreasing bodyweight and then randomly allocated within replicates of two animals to one of the treatment groups. Each cat in the treated group received one topical application of the combination product at the minimum therapeutic dose of 0.12mL/kg body weight delivering 10mg fipronil+12mg (S)-methoprene+0.5mg eprinomectin+10mg praziquantel per kilogram of body weight while the cats allocated to the control group remained untreated. For parasite recovery, identification and count, cats were euthanized humanely 14 days after treatment. All untreated cats harboured Capillaria plica in their urinary bladders (range 4–12), while no capillarids were recovered from the eight treated cats. Thus, the efficacy of the novel topical combination against C. plica was 100%. All cats accepted the treatment well based on post-treatment observations and daily observations thereafter. No adverse events or other health problems were observed during the study. [ABSTRACT FROM AUTHOR]

Four studies were conducted to determine the pharmacokinetic characteristics and in vitro metabolism of eprinomectin, a semi-synthetic avermectin, in cats. Pharmacokinetic parameters including bioavailability of eprinomectin were determined in a parallel study design comprised of one group of eight cats which were treated once topically at 0.12mL/kg bodyweight with BROADLINEÃ?®, a novel combination product (fipronil 8.3% (w/v), (S)-methoprene 10% (w/v), eprinomectin 0.4% (w/v) and praziquantel 8.3% (w/v)), delivering a dose of 0.5mg eprinomectin per kg body weight, and a group of six cats which received 0.4% (w/v) eprinomectin at 0.4mg/kg bodyweight once by intravenous injection. For cats treated by topical application, the average eprinomectin (B1a component) maximum plasma concentration (C max) was 20ng/mL. The maximum concentrations were reached 24h after dosing in the majority of the animals (six of eight cats). The average terminal half-life was 114h due to slow absorption (‘flip-flop’ kinetics). Following intravenous administration the average C max was 503ng/mL at 5min post-dose, and the mean elimination half-life was 23h. Eprinomectin was widely distributed with a mean volume of distribution of 2390mL/kg, and the clearance rate was 81mL/h/kg. Mean areas under the plasma concentration versus time curves extrapolated to infinity were 2100ngh/mL and 5160ngh/mL for the topical and intravenous doses, respectively. Topical eprinomectin was absorbed with an average absolute bioavailability of 31%. In a second parallel design study, the dose proportionality of eprinomectin after single topical administration of BROADLINEÃ?® was studied. Four groups of eight cats each were treated once topically with 0.5, 1, 2 or 5 times the minimum recommended dose of the combination, 0.12mL/kg bodyweight. Based on comparison of areas under the plasma concentration versus time curves from the time of dosing to the last time point at which eprinomectin B1a was quantified, and C max, dose proportionality was established. In addition, the metabolic pathway of eprinomectin using cat liver microsomes, and plasma protein binding using cat, rat, and dog plasma were studied in vitro. Results of the analyses of eprinomectin B1a described here showed that it is metabolically stable and highly protein bound (>99%), and thus likely to be, as with other species, excreted mainly as unchanged parent drug in the feces of cats. [ABSTRACT FROM AUTHOR]

Five controlled, blinded and randomized studies were conducted to examine the efficacy of a single topical application of a combination of fipronil, (S)-methoprene, eprinomectin, and praziquantel (BROADLINE®, Merial) against induced infestations with Ixodes ticks on cats. Three studies investigated the efficacy against Ixodes ricinus and two against Ixodes scapularis. In each study, purpose-bred cats were assigned at random to an untreated group or to a treated group. For the studies using I. ricinus, cats were infested with 50 female ticks and a similar number of males 2 days before treatment application, and weekly afterwards on between four and six occasions. For the studies using I. scapularis, cats were infested with a total of 50 ticks (approximately 25 females and 25 males) according to the same schedule as for I. ricinus. Tick counts for the evaluation of efficacy were performed 48h after treatment and 48h after the subsequent weekly infestations. Weekly attachment rates to untreated cats of at least 29% for I. ricinus and at least 30% for I. scapularis demonstrated consistently that the ticks were vigorous and that the attachment rates were adequate for efficacy evaluation. In the I. ricinus studies, an efficacy of at least 93% was demonstrated for up to 37 days after the treatment. In the I. scapularis studies, the efficacy level was at least 95% 30 days after the treatment. The product was well tolerated and caused no adverse reaction. [ABSTRACT FROM AUTHOR]

The efficacy of a novel topical combination of fipronil 8.3% (w/v), (S)-methoprene 10% (w/v), eprinomectin 0.4% (w/v), and praziquantel 8.3% (w/v) (BROADLINEÃ?®, Merial) was evaluated against adult and larval Toxocara cati in four controlled studies. All studies included experimentally infected, purpose-bred, short-haired cats. In two studies, 22 or 20 cats harbouring patent infections as confirmed by pre-treatment faecal examination, were included. Within each study, cats were allocated to one of two groups: control or treated. In a further two studies, 30 cats were included in each; cats were allocated to one of three groups: control, treated when T. cati were expected to be either migrating third and/or fourth-stage larvae, or treated when T. cati were expected to be fourth-stage larvae. Cats allocated to the treated groups received a single topical application of the combination product at 0.12mL/kg bodyweight (10mg fipronil+12mg (S)-methoprene+0.5mg eprinomectin+10mg praziquantel per kg). For parasite recovery and count, cats were euthanized humanely at different intervals after treatment. In the studies targeting adult T. cati, ascarids were recovered from all controls (range 1–150) while only two worms were isolated from one treated cat. Thus, the efficacy of the novel combination was 99.4% and 100% against adult T. cati. For studies targeting larval T. cati, up to 21 worms were recovered from each of seven or eight of the control cats per study. No T. cati were recovered from the treated cats in two studies, corresponding to 100% efficacy against both, migrating third and/or fourth-stage larvae and luminal fourth-stage larvae. All cats accepted the treatment well and no adverse experiences or other health problems were observed throughout the studies. [ABSTRACT FROM AUTHOR]

Background A study was conducted to evaluate and compare the effectiveness of two different spot-on topical flea products to control flea infestations on naturally infested dogs and cats in Tampa, FL USA. Methods Thirty-two dogs and 3 cats with natural flea infestations living in 18 homes were treated topically with a 19.53% w/w spot-on formulation of indoxacarb. Another thirty dogs and 2 cats living in 19 different homes were treated topically with either fipronil (9.8% w/w)/(s)-methoprene (8.89% w/w) or fipronil (9.8% w/w)/(s)-methoprene (11.8% w/w), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28-30, 40-45, and 54-60. Results A single application of the indoxacarb or fipronil (s)-methoprene formulations reduced flea populations on pets by 97.8% and 85.5%, respectively within 7 days. One month (28-30 days) after treatment the indoxacarb and fipronil (s)-methoprene formulations reduced onanimal flea burdens by 95.0% and 49.5%, respectively. Following two monthly applications of either the indoxacarb or fipronil (s)-methoprene formulations, pet flea burdens were reduced by 99.1% and 54.8%, respectively, by days 54-60. At the end of the two month study, 77.1% and 15.6% of the dogs and cats in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively were flea free. Flea numbers in the indoor-premises were markedly reduced in both treatment groups by days 54-60, with 97.7% and 84.6% reductions in intermittent-light flea trap counts in the indoxacarb and fipronil (s)-methoprene treatment groups, respectively. Conclusions This in-home investigation conducted during the summer of 2013 in subtropical Tampa, FL, is the first published U.S field investigation of the indoxacarb topical formulation. The indoxacarb formulation was able to effectively control flea populations in heavily flea infested pets and homes. The efficacy achieved by the fipronil (s)-methoprene formulation against flea infestations on these pets was lower than in previous investigations using the same study design. [ABSTRACT FROM AUTHOR]

Abstract: Background: Two studies evaluating the efficacy of an imidacloprid/flumethrin collar (Seresto&Reg;, Bayer Animal Health, IVP), a deltamethrin collar (Scalibor®, MSD, CP1), a fipronil/(s)-methoprene spot-on (Frontline ComboW, Merial, CP2), a dinotefuran/pyriproxyfen/permethrin spot-on (Vectra 3D®, Ceva, CP3) and an amitraz/fipronil/(s)-methoprene spot-on (Certifect ®, Merial, CP4/CP5) against repeated infestations with Rhipicephalus sanguineus and Ctenocephalides felis felis on dogs were conducted over periods of 226 days and 71 days respectively. Methods: The first study comprised 4 groups of treated dogs and one untreated control group, and the second 3 groups of treated dogs and one control group. Each group consisted of 8 dogs. All dogs were infested with ticks and fleas at regular intervals. Ticks were counted 6 h, 18 h or 48 h after infestations and fleas 24 h after infestations. Efficacies of the treatments were calculated by comparison with the untreated control groups using standard descriptive statistics. Results: The protective 48 h tick efficacy was 97.8% to 100% for the IVP (226 days), 69.3% to 97.4% for CP1 (170 days), 99.6% to 43.4% for CP2 (35 days) and 98% to 61.4% for CP3 (35 days).The protective 18 h tick efficacy was 98% to 99.6% for the IVP (71 days), 100% to 86.5% for CP4 (29 days), 100% to 72.8% for CP4 after re-treatment (35 days) and 98.8% to 54.3% for CP5 (35 days).The protective 6 h tick efficacy was 85.6% at Day 7 and 90.1% to 97.1% from Day 14 onwards for the IVP (70 days), 92.3% to 70.7% for CP4 (35 days), 97.5% to 65.2% for CP4 after re-treatment (35 days) and 95.1% to 51.8% for CP5 (35 days). The protective 24 h flea efficacy was 99.5/90.9% to 100% for the IVP (71/226 days), 66.7% to 83% for CP1 (170 days), 100% to 88.5% for CP2 (35 days), 100% to 73.3% for CP3 (35 days), 100% to 98.7% for CP4 (35 days), 100% to 87.5% for CP4 after re-treatment (35 days) and 100% to 79.5% for CP5 (35 days). [ABSTRACT FROM AUTHOR]

Abstract: Thirteen cats and 7 dogs living in 14 homes were treated topically with either a dinotefuran (22%, w/w)/pyriproxyfen (3.00%, w/w) (DP) or dinotefuran (4.95%, w/w)/pyriproxyfen (0.44%, w/w)/permethrin (36.08%, w/w) (DPP) topical spot-on, respectively. Twenty cats and 7 dogs living in 16 homes were treated topically with either a fipronil (9.8%, w/w)/(S)-methoprene (11.8%, w/w) or fipronil (9.8%, w/w)/(S)-methoprene (8.8%, w/w) topical spot-on (FM), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28–30, 40–45, and 54–60. A single application of the DP–DPP and FM formations reduced flea populations by 87.35% and 88.44%, respectively within 7 days. Following two monthly applications of either the DP–DPP or FM formulations, pet flea burdens were reduced by 95.24% and 95.47%, respectively. Flea numbers in the indoor-premises were also markedly reduced by days 54–60, with 98.05% and 96.15% reductions in intermittent-light flea trap counts in the DP–DPP or FM treatment groups, respectively. [Copyright &y& Elsevier]

Abstract: Four studies were conducted to show the effectiveness of a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT™, Merial Limited, GA, USA) for the therapeutic and preventive control of Ixodid tick species affecting dogs in Europe: Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus. In each, untreated control dogs were compared to others treated with the novel combination. All dogs were infested with 50 adult, unfed ticks prior to treatment and at 7-day intervals after treatment. Ticks on all dogs were counted at 18, 24 and 48h after treatment (therapeutic efficacy) or infestation (preventive efficacy). Therapeutic efficacy of fipronil, amitraz and (S)-methoprene was excellent as shown by significant (p <0.05) and greater than 97% and up to 100% reductions in the 48h tick counts and significant (p <0.05) detachment/death of ticks evident at 18–24h after treatment for all three tick species. Preventive efficacy was demonstrated by significant (p <0.05) and greater than 93% and up to 100% reductions in tick counts at 48h after repeat infestations out to 35 days after treatment for I. ricinus and out to 42 days after treatment for D. reticulatus and R. sanguineus. The time to substantial disruption of establishment of new tick infestations after treatment was less than 18–24h and was maintained for up to 28 days after treatment of I. ricinus and D. reticulatus infestations, and 4h to at most 18h and maintained up to 35 days after treatment of R. sanguineus. Similar preventive efficacy profiles for each of the Ixodid species tested suggest that CERTIFECT kills all Ixodid species starting 4h after contact as demonstrated for R. sanguineus. [Copyright &y& Elsevier]

Abstract: This investigation focused primarily on the interaction of two benzophenanthridine alkaloids (chelerythrine and sanguinarine), piperonyl butoxide and (S)-methoprene with G-protein-coupled cannabinoid CB1 receptors of mouse brain in vitro. Chelerythrine and sanguinarine inhibited the binding of the CB1 receptor agonist [3H]CP-55940 to mouse whole brain membranes at low micromolar concentrations (IC50s: chelerythrine 2.20μM; sanguinarine 1.10μM). The structurally related isoquinoline alkaloids (berberine and papaverine) and the phthalide isoquinoline ((−)-β-hydrastine) were either inactive or considerably below IC50 at 30μM. Chelerythrine and sanguinarine antagonized CP-55940-stimulated binding of [35S] GTPγS to the G-protein (IC50s: chelerythrine 2.09μM; sanguinarine 1.22μM). In contrast to AM251, both compounds strongly inhibited basal binding of [35S]GTPγS (IC50s: chelerythrine 10.06μM; sanguinarine 5.19μM). Piperonyl butoxide and S-methoprene inhibited the binding of [3H]CP-55940 (IC50s: piperonyl butoxide 8.2μM; methoprene 16.4μM), and also inhibited agonist-stimulated (but not basal) binding of [35S]GTPγS to brain membranes (IC50s: piperonyl butoxide 22.5μM; (S)-methoprene 19.31μM). PMSF did not modify the inhibitory effect of (S)-methoprene on [3H]CP-55940 binding. Our data suggest that chelerythrine and sanguinarine are effacacious antagonists of G-protein-coupled CB1 receptors. They exhibit lower potencies compared to many conventional CB1 receptor blockers but act differently to AM251. Reverse modulation of CB1 receptor agonist binding resulting from benzophenanthridines engaging with the G-protein component may explain this difference. Piperonyl butoxide and (S)-methoprene are effacacious, low potency, neutral antagonists of CB1 receptors. Certain of the study compounds may represent useful starting structures for development of novel/more potent G-protein-coupled CB1 receptor blocking drugs. [Copyright &y& Elsevier]

Abstract: Monitoring of the performance of flea control products under conditions of natural challenge is valuable in assessing continued effectiveness and determining the ongoing relevance of laboratory studies. A multi-clinic, investigator-blinded study was undertaken in client-owned dogs to investigate and compare the flea control provided by 3 consecutive monthly treatments of oral spinosad (SPN) or fipronil/(S)-methoprene topical (FSM) spot-on. The first household dog meeting enrollment criteria and with at least 10 fleas (whole-body flea count) served as the index dog in a household against which primary objectives were set. Stratification was based on pruritus scores at the enrollment visit and on single or multiple pet household. Index pets were randomized to treatment with either SPN or FSM, dispensed on day 0 for at-home administration by owners. All other household dogs and cats, maximum 4 pets per household, were dispensed the same treatment as the index dog (spinetoram was dispensed for cats in SPN households). Subsequent treatments were dispensed when index dogs were returned for whole-body flea counts and pruritus-scoring at visits on days 30 and 60, with final assessments on day 90 (±5 days on each occasion). Primary endpoints were the number of flea-free index dogs in each group one month after the final treatment, the reduction in owner-reported pruritus, and the reduction from baseline mean flea counts. One hundred twenty eight index dogs were enrolled (65 in the SPN arm; 63 in the FSM arm) at 10 clinics in FL (6), NC (2), LA (1), and TX (1). On day 0, geometric mean flea counts were 57.7 (range: 10–1469) and 44.8 (10–717) for the SPN and FSM groups, respectively. On Day 90, 55 of 58 (95%) and 21 of 55 (38%) index dogs completing the study were flea-free in SPN and FSM groups, respectively; mean SPN pruritus scores declined to 0.92 (6.67 on day 0), and to 3.83 (6.33 on day 0) for FSM; geometric mean flea counts (% control) were 0.08 (99.9%) and 5.19 (88.4%), for SPN and FSM groups, respectively. Between-treatment differences were highly statistically significant (p <0.0001). In conclusion, SPN provided reliable flea control in client-owned dogs, regardless of challenge level. [Copyright &y& Elsevier]

Abstract: Four laboratory studies were conducted to demonstrate that a single topical dose of a novel spot-on combination containing fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) is efficacious against the brown dog tick, Rhipicephalus sanguineus. In each study, 6–8 male and 6–8 female purpose-bred, laboratory mongrels, terrier cross or Beagles were randomly assigned to one of two study groups (treated and untreated), based on pre-treatment parasite counts. Starting on the day before treatment, each dog was infested weekly with 50 ticks. Ticks were thumb counted at various time points after treatment and weekly infestations starting as early as 6h and continued at 12, 18 and 24h depending on the study. Ticks were removed and counted at 48h after treatment and weekly infestations. CERTIFECT provided rapid and excellent control of pre-existing and newly acquired infestations of R. sanguineus with efficacy as high as 93% within the first 12h after a single topical treatment. Excellent control (>96%) of R. sanguineus as early as 18h, following post treatment infestations was maintained for at least 35 days. [Copyright &y& Elsevier]

Abstract: Four groups of seven dogs were treated topically with a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT™, Merial Limited, GA, USA) on 28, 21, 14 and 7 days prior to tick infestation, respectively and acaricidal efficacy and transmission blocking compared with an untreated control group (seven dogs). All dogs were infested with adult Dermacentor reticulatus ticks harbouring Babesia canis canis. Babesia canis canis was transmitted by D. reticulatus to all seven untreated control dogs, confirmed following demonstration of clinical signs, by the detection of B. canis parasites in thin blood smears and B. canis canis PCR-RLB DNA assay on blood and the development of B. canis canis antibody titres by 14–21 days after tick infestation. The majority of treated dogs remained sero-negative for 42 days after infestation. Therefore, the treatment of dogs with CERTIFECT applied up to 28 days prior to infestation with D. reticulatus harbouring B. canis canis, successfully prevented the development of clinical signs of canine babesiosis. [Copyright &y& Elsevier]

Abstract: Healthy, purpose-bred laboratory beagle dogs that had not been exposed to ticks and were seronegative for Borrelia burgdorferi and Anaplasma phagocytophilum were randomly assigned to four groups of eight dogs each. Control group 1 was not treated. Groups 2, 3 and 4 were treated with a single topical application of a new formulation of fipronil, amitraz and (S)-methoprene (CERTIFECT™, Merial Limited, GA, USA) at 28, 21 or 14 days prior to tick infestation, respectively. Each dog was infested with 25 female and 25 male field-collected adult Ixodes scapularis ticks that had infection rates of 66% for B. burgdorferi sensu stricto and 23% for A. phagocytophilum, as determined by polymerase chain reaction. Two and five days after tick infestation, control dogs had an average of 9.5 and 13.9 attached adult female ticks, respectively, whilst the 24 treated dogs remained tick-free aside from a single tick on the 2nd day after infestation. Serial serological tests demonstrated that the ticks successfully infected 8/8 control dogs with B. burgdorferi and co-infected 6/8 with A. phagocytophilum. B. burgdorferi infection also was confirmed in most control dogs by culture (6/8) and PCR (7/8) of skin biopsies. In contrast, CERTIFECT protected all 24 treated dogs against infection by both B. burgdorferi and A. phagocytophilum, as demonstrated by their negative serological tests throughout the study and the absence of any positive skin biopsy culture or PCR in these dogs. [Copyright &y& Elsevier]

An isocratic reversed-phase high-performance liquid chromatographic (RP-HPLC) method development for the simultaneous determination of five active ingredients (S)-methoprene, MGK264, PBO, sumithrin and permethrin in a new complex pesticide formulation is described. These active ingredients have similar polarities and contain isomers. The RP-HPLC method development approach began with the selection of a column based on the component structure information, bonded phase, and particle physical characteristics. Second, the mobile phase composition was changed to improve peak resolution and peak sensitivity, especially with analytes containing isomers. Choosing the match between the stationary phase and mobile phase composition, the developed RP-HPLC method not only can simplify the procedure appreciably but also significantly decrease total analysis time and increase peak height. The developed isocratic RP-HPLC method for the analysis of this new formulation was then validated for specificity, linearity, precision, and accuracy. The chromatographic peak identification was identified by LC–MS using the electrospray ionisation in the positive-ion mode. [Copyright &y& Elsevier]

Abstract: Preventing tick bites is a fundamental step towards reducing the impact of tick-borne protozoal, bacterial and viral diseases (TBDs) in humans and animals. The aim of this study was to evaluate the efficacy of a combination of imidacloprid 10%/permethrin 50% and of fipronil 10%/S-methoprene 12% against ticks in naturally infected dogs and to assess methodological parameters to calculate drug efficacy on tick immature stages. From July to August 2004, 45 privately owned dogs of various sexes, ages, breeds, coat length and habits were enrolled in a trial carried out in an area (radius approximately 50km) in Southern Italy. Three homogeneous groups (both for dog population and tick population) were formed: 15 dogs treated with imidacloprid 10% and permethrin 50% spot-on (group A), 15 dogs treated with fipronil 10% and methoprene 12% spot-on (group B) and 15 untreated dogs (group C). The dogs in each group were then sub-grouped according to their age and weight. Two different treatments were administered (time 0 and +28 days) to groups A and B, and the dogs were checked weekly for tick infestation until day +56 post-treatment (p.t.). Twenty-four areas distributed on the whole body surface were examined for ticks at each follow-up, while only at time 0 and at day +56 p.t., ticks were collected from the dogs and identified. For the immature stages a semi-quantitative method was adopted and the load of immature stages was evaluated and grouped into four classes up to day +56 p.t. when the mean number of immature ticks (MIT) for each infection class was evaluated. All the adult ticks collected were identified as brown dog ticks (Rhipicephalus sanguineus). Immature stages were first compared at day +28 p.t.. The efficacy of both products used in groups A and B on adult ticks was high and generally very similar. Conversely, the efficacy of imidacloprid 10% and permethrin 50% against immatures was higher than that of fipronil 10% and methoprene 12% throughout the observation period with statistically significant differences (p &#60;0.05) at day +28 p.t. (i.e. group A=98.52%, group B=72.40%). On the whole, in analysing the efficacy of both products against adult plus immature ticks, it was found that the combination of imidacloprid 10% and permethrin 50% was more effective than fipronil 10% and methoprene 12%, with the differences being statistically significant at day +28 p.t. (group A=98.43%, group B=77.56%). [Copyright &y& Elsevier]

A controlled clinical trial was carried out to assess the effectiveness of pyriprole, metaflumizone combined with amitraz, and fipronil-(S)-methoprene commercial spot-on products in preventing adult female Culex pipiens pipiens from feeding on dogs. Twenty-four beagle dogs were tested for their attractiveness to the mosquitoes and ranked accordingly to produce four groups of equivalent sensitivity to mosquitoes; six were treated with the pyriprole spot-on, six with the metaflumizone combined with amitraz spot-on, six with the fipronil-(S)-methoprene spot-on, and six were left untreated. All the dogs were challenged with 50 unfed adult female Culex in cages for one hour seven days before the treatment, and one and seven days after it. The mosquitoes were checked for blood feeding after one hour and for mortality 24 hours after they had been released into the cages. There was a significant reduction in the number of engorged mosquitoes only with the fipronil-(S)-methoprene product and there were significantly more dead mosquitoes with this product and the pyriprole product, but their effects were too small for them to be recommended for use in a dirofilariosis prevention programme. [ABSTRACT FROM AUTHOR]

• Bathing dogs that were not treated did not affect R. sanguineus s. l. burden • Bathing dogs that were not treated affected R. C. f. felis burden • Bathing dogs resulted in a shorter duration of the product used • Bathing dogs resulted in a shorter residual efficacy against ticks and fleas This work evaluated tick and flea burdens and the efficacy of a single topical application of 10% fipronil + 9% (S)-methoprene spot-on against experimental infestations of Rhipicephalus sanguineus sensu lato and Ctenocephalides felis felis on dogs that were submitted to regular baths for 56-days post-treatment. Four treatments (n = 24) were evaluated: no chemical treatment and no bathing (T01); no chemical treatment + bathing (T02); chemical treatment and no bathing (T03) and chemical treatment + bathing (T04). Dogs were infested with adult ticks and fleas seven days pre-treatment (-7). The ectoparasites were then counted and removed on day -5, followed by a new infestation on day -2 and treatment on day 0. Ticks and fleas were then counted without removal on day 1 and counted with removal on day 2. The dogs were then repeatedly infested with both ectoparasites on days 5, 12, 19, 26, 33, 40, 47 and 54 post-treatment. Baths and ectoparasite counts with removal were performed every 48 h before and after experimental infestation, respectively. Animals of T04 had lower (P ≤ 0.05) tick burden than animals from T01 and T02 from day 2 to day 28. For fleas, the counts varied among days of the study. Dogs from T03 presented lower (P ≤ 0.05) flea burden than dogs from T01 from day 1 until day 56. The same was true for T04 when compared to T01 from day 1 to day 42. Animals of T02 greater (P ≤ 0.05) flea burden than animals of T04 in all dates post treatment. In addition, dogs from T02 presented higher (P ≤ 0.05) flea burden than T01 from day 7 to day 28 and from day 49 to day 56. In sum, the efficacy of the spot-on formulation used declined over the time against both ectoparasites. The efficacy for ticks ranged from 0.0 to 96.5% and 0.0 to 98.52% for T03 and T04, respectively. While for fleas, the efficacy of the formulation ranged from 67.41 to 100% for T03 and 40.18 to 100% for T04. So, bathing dogs that were not treated increased C. f. felis burden but not R. sanguineus s. l. burden. The residual efficacy of the product had a shorter duration against these ectoparasites for dogs that received subsequent bathing. [ABSTRACT FROM AUTHOR]