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Background: A recent American Heartworm Society (AHS) survey on the incidence of adult heartworm infections in dogs in the United States of America showed a 21.7% increase in the average cases per veterinary clinic from 2013 to 2016. The analysis reported here was performed to see if heartworm testing results available via the Companion Animal Parasite Council (CAPC) aligned with the AHS survey and whether changes in heartworm preventive dispensing accounts for the increased incidence. The resistance of Dirofilaria immitis to macrocyclic lactones (MLs) has been previously reported. Methods: An analysis of 7-9 million heartworm antigen tests reported annually to the Companion Animal Parasite Council (CAPC) from 2013 to 2016 was conducted and compared to the 2016 AHS survey. A state-by-state analysis across the southeastern USA was also performed. National heartworm preventive dispensing data were obtained from Vetstreet LLC and analyzed. All oral, topical and injectable heartworm preventives were included in this analysis, with injectable moxidectin counting as six doses. Results: Positive antigen tests increased by 15.28% from 2013 to 2016, similar to the 21.7% increase reported by the AHS survey. Incidence in the southeastern USA increased by17.9% while the rest of USA incidence increased by 11.4%. State-by-state analysis across the southeastern USA revealed an increased positive test frequency greater than 10% in 9 of 12 states evaluated. During this time, the overall proportion of dogs receiving heartworm prophylaxis remained relatively unchanged. Approximately 2/3 of the dogs in the USA received no heartworm prevention each year. Conclusion: These CAPC data show the rate of positive heartworm tests increasing significantly (P < 0.0001) in the USA from 2013 to 2016, with a higher rate of increase in the southeastern USA than nationally. Only 1/3 of dogs in the USA were dispensed one or more doses of heartworm prevention annually by veterinarians, averaging 8.6 monthly doses/year. Veterinarians and pet owners should work together to follow CAPC and AHS guidelines to protect dogs from infection with D. immitis. Lack of preventive use and the emergence of heartworm resistance to MLs could both be impacting the increased rate of positive heartworm tests in dogs. [ABSTRACT FROM AUTHOR]

Background: Lotilaner is a novel isoxazoline developed for oral administration to dogs. In laboratory studies, lotilaner was shown to be safe and to produce a rapid flea and tick knockdown, with a sustained speed of kill for at least a month post-treatment. A study was undertaken to demonstrate the efficacy, safety and palatability of three monthly doses of lotilaner flavoured chewable tablets (Credelio™, Elanco) in controlling fleas under field conditions in Europe. Methods: Dogs were enrolled at 17 veterinary clinics across Germany, Hungary and Portugal. Qualifying households having no more than three dogs and one primary dog with at least five fleas was randomised 2:1 to a lotilaner (minimum dose rate 20 mg/kg) or a topical fipronil group (administered per label). There were 128 and 64 households allocated to the lotilaner and fipronil groups, respectively. Treatments were dispensed to owners on Days 0, 28 and 56; supplementary household dogs received the same treatment as the primary dog. Post-enrollment flea counts and flea allergy dermatitis (FAD) assessments were made on primary dogs on Days 14, 28, 56 and 84. Efficacy calculations were based on geometric mean percent reductions of live flea counts versus pre-treatment counts on Day 0. The safety and palatability of lotilaner tablets were also assessed. Results: Lotilaner efficacy was 99.1, 99.5, 99.9 and 99.8% on Days 14, 28, 56 and 84, respectively. Corresponding reductions for fipronil were 93.4, 91.2, 94.4 and 97.0%. Lotilaner was superior to fipronil at all post-Day 0 assessments (t(186) ≥ 3.43, P ≤ 0.0007). At every post-treatment assessment, at least 90% of lotilaner-treated dogs were flea-free (98. 4% on Day 84); fewer than 90% of fipronil group dogs were flea-free on the same time points. Lotilaner flavoured chewable tablets were palatable, and both products were well tolerated. Lotilaner alleviated or eliminated clinical signs of FAD, including pruritus. Conclusions: Under field conditions in Europe, lotilaner flavoured chewable tablets were greater than 99% effective in eliminating fleas from dogs at the first post-treatment assessment (Day 14). Efficacy was maintained through Day 84, with corresponding improvements in FAD. Lotilaner tablets were palatable and safe and provided superior flea control to fipronil. [ABSTRACT FROM AUTHOR]

Background: Effective control of tick infestations on dogs is important to reduce the risk of transmission of bacterial, viral, and protozoal pathogens. Laboratory studies were initiated to determine the efficacy of lotilaner against common ticks infesting dogs in the United States. Methods: Eight studies investigated the efficacy of lotilaner against ticks. In two studies dogs were infested with both Dermacentor variabilis and Rhipicephalus sanguineus: one additional study was completed for each of these species. Two studies assessed infestations with Amblyomma americanum and two with Ixodes scapularis. In all studies, dogs were ranked and blocked by counts from pre-treatment infestations and randomly allocated, at least eight per group, to be treated orally with lotilaner (minimum dose rate 20 mg/kg), or to be untreated controls. Treatments were administered on Day 0, within 30 min after dogs were fed. In all studies, infestations were performed with 50 adult ticks on Days -2, 7, 14, 21 and 28, and also on Day 35 for R. sanguineus, D. variabilis and I. scapularis. Tick counts were completed 48 h after treatment or after each subsequent challenge. An adequate infestation was defined as at least 25% of the infestation dose recovered from each of at least six control animals at each evaluation. Efficacy calculations for the primary objective were based on geometric means. Results: In all studies, lotilaner was 100% effective against existing infestations. For post-treatment assessments, on only two occasions did efficacy fall below 99%: in one D. variabilis study efficacy was 98.0% on Day 35 and in one I. scapularis study efficacy on Day 16 was 98.4%. Only mild and transient adverse events were observed, and none were considered to be related to treatment. Conclusion: Lotilaner was completely effective against existing infestations with four common species of ticks, D. variabilis, R. sanguineus, A. americanum and I. scapularis, that affect dogs in North America, with at least 4 weeks efficacy of 98.0% or more against subsequent challenge infestations. These results show that lotilaner is a highly effective isoxazoline that offers sustained efficacy against ticks through and beyond the one-month end-of-dose treatment interval. [ABSTRACT FROM AUTHOR]

Background: There is a continuing need for novel approaches to tick control in dogs. One such approach lies in the ability of lotilaner (Credelio™), an isoxazoline with a rapid onset of action, to provide sustained efficacy against ticks. Two studies were undertaken to confirm lotilaner's efficacy, at the minimum dose rate of 20 mg/kg, against the three most common tick species in Europe. Methods: In each of two studies, 16 Beagle dogs, at least 6 months old, were ranked and blocked by tick counts from infestations placed approximately 1 week before treatment. Within blocks, dogs were randomized to receive either lotilaner flavoured chewable tablets at as close as possible to, but not less than the minimum dose rate of 20 mg/kg, or to be sham-treated controls. Study 1 assessed lotilaner efficacy against concurrent infestations with 50 (± 6) Rhipicephalus sanguineus and 70 (± 6) Ixodes ricinus; Study 2 infestations were with 50 (± 2) Dermacentor reticulatus. Infestations were performed on Day -2 with counts on Day 2, 48 (± 2) hours post-treatment. Post-treatment infestations were performed on Days 7, 14, 21, 28 and 35, and ticks were counted 48 (±2) hours post-infestations. Efficacy was determined by the percent reduction in mean live tick counts. Results: Control group infestations for each tick species were adequate for assessing lotilaner efficacy at all assessment times. On Day 2 no live ticks were found on any lotilaner-treated dog. For subsequent counts, in Study 1 lotilaner was 100% effective in eliminating live I. ricinus and R. sanguineus on all but two occasions for each tick; on each of those occasions efficacy was sustained at greater than 98.0%. In Study 2, except for a single unattached live tick found on Day 16, efficacy against D. reticulatus was 100% at every post-treatment assessment. Conclusion: The high and sustained efficacy against the three common species of ticks in Europe, R. sanguineus, I. ricinus and D. reticulatus, demonstrates that lotilaner can be a valuable tool in the treatment of canine tick infestations. Lotilaner flavoured chewable tablets were well tolerated and effectiveness was sustained through at least 35 days. [ABSTRACT FROM AUTHOR]

Background: Oral administration of lotilaner flavoured chewable tablets (Credelio™, Elanco) to dogs has been shown to provide a rapid onset of killing activity of infesting ticks, with sustained efficacy for at least 35 days. A study was undertaken in Europe to confirm lotilaner's safety and anti-tick efficacy in client-owned dogs. Methods: In this assessor-blinded study, dogs were enrolled at 19 clinics in Germany, Hungary and Portugal. Qualifying households with no more than three dogs were randomized in an approximate 2:1 ratio to a lotilaner or fipronil/(S)-methoprene (FSM) (Frontline® Combo Spot-on, Merial) treatment group. One household dog with at least three live attached ticks was the primary dog. Treatments were dispensed Days 0, 28 (± 2) and 56 (± 2) for owner administration to all household dogs. Tick counts were performed on primary dogs Days 7 (± 1), and ±2 days on Days 14, 21, 28, 42, 56, 70 and 84; supplementary dogs were assessed for safety ± 2 days on Days 28, 56 and 84. Efficacy was assessed by comparing mean Day 0 live attached tick counts with subsequent counts. Results: The most frequently retrieved ticks were Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus (sensu lato), with Ixodes hexagonus also present. In the lotilaner group (n = 127) geometric mean tick count reductions were at least 98% from the first post-treatment visit (Day 7) through Day 56, when efficacy was 100%. For FSM (n = 68), efficacy remained at least 96% through Day 84, but at no point were all dogs free of live attached ticks. Mean counts in lotilaner-treated dogs were significantly lower than FSM-treated dogs on Days 7, 42, 70 and 84 (P < 0.05). Percent efficacy over all post-enrolment visits was 99.3 and 98.3% for lotilaner and FSM groups, respectively (t(190) = 2.23, P = 0.0268). Owners successfully administered all treatments, and both products were well-tolerated. Conclusion: Under European field conditions, lotilaner flavoured chewable tablets administered monthly, were > 98% effective in eliminating live ticks from the first post-treatment assessment (Day 7) through Day 56 and maintained 100% of dogs tick-free on Days 70 and 84. Lotilaner was safe, providing superior tick control to FSM administered according to the same schedule. [ABSTRACT FROM AUTHOR]

Background: Lotilaner (Credelio™) is the newest member of the novel isoxazoline chemical class to be developed to treat canine ectoparasitism. Administered orally, lotilaner is rapidly absorbed with peak blood levels occurring within 2 h post-treatment. A study was undertaken to determine the earliest onset of lotilaner's efficacy against existing flea infestations. Methods: From 72 Beagles, 64 qualifying dogs were ranked in descending order of flea counts from a Day -8 infestation and placed into eight blocks. Within blocks, eight dogs were randomly allocated among eight groups: Groups 1 to 4 were treated orally with lotilaner, at as close as possible to the minimum dose rate of 20 mg/kg within 30 (± 5) minutes after feeding; Groups 5 to 8 were untreated controls. All dogs were infested with 100 ± 5 fleas on Day -2, and whole-body flea counts were completed at 30 min and one, two and 8 h after treatment. Efficacy calculations were based on arithmetic and geometric means if an adequate infestation (at least six of eight untreated dogs with a flea retention of ≥ 50%) was demonstrated in the equivalent control group. Results: Adequate infestations were established in all control groups. At 30 min and 1 h post-treatment, relative to the matching untreated control group, there were no significant reductions in mean flea counts in lotilaner-treated dogs, although moribund fleas were evident at 1 h post-treatment. At 2 h after treatment, compared with the equivalent control group, the geometric mean flea count reduction in the lotilaner group was 64.0% (t(7) = 2.86, P = 0.0242). At 8 h after treatment, lotilaner efficacy was 99.6%. There were no treatment-related adverse events. Conclusion: This study demonstrates that lotilaner flavored chewable tablets are well tolerated and begin to kill fleas within 2 h of treatment, achieving 99.6% efficacy within 8 h. Lotilaner can therefore be used to quickly alleviate the flea irritation that arises from existing infestations. [ABSTRACT FROM AUTHOR]

Background: Dogs worldwide are at risk of Babesia spp. infections. Preventive efficacy of lotilaner tablets (Credelio™, Elanco) against Babesia canis was evaluated in two studies. Methods: Sixteen dogs in Study 1 and 12 dogs in Study 2, all seronegative and polymerase chain reaction (PCR) negative for B. canis, were randomized to a sham-treated control group or a lotilaner (20-43 mg/kg) treatment group, administered on Day 0 (Study 1: n = 8/group; Study 2: n = 6/group). Dogs were each infested with 50 Dermacentor reticulatus, a percentage of which (Study 1: 8.0-30.0%; Study 2: 12.2%) were infected with B. canis, in Study 1 on Days 2, 7, 14, 21 and 28, and in Study 2 on Day 28. Ticks were removed and counted on Day 30 in Study 1, and Day 34 in Study 2. Blood was collected for Babesia detection via smear, PCR and immunofluorescence assay (IFA) in Study 1 on Day 2, then approximately weekly through Day 56, and in Study 2 at weekly intervals between Days 28 to 49, and on Days 63 and 91. Additional samples were collected from dogs with body temperature > 39.4 °C (measured three times weekly, from Days 7 to 56 in Study 1 and from Days 35 to 56 in Study 2) and positive for B. canis on blood smear. Dogs with confirmed infections were rescue-treated, removed from the study and, in Study 1, replaced. Results: Across both studies B. canis infection of ticks ranged between 8.0-30.0%. In Study 1, all control dogs were positive for B. canis on blood smear and PCR on Day 10 and IFA on Day 21; on Day 21 seven of eight replacement control dogs were B. canis-positive; no replacement dogs were B. canis-positive following tick removal on Day 30. In Study 2, all control dogs were B. canis-positive on Day 56. All lotilaner-treated dogs remained B. canis-negative at all assessments in both studies. Conclusion: Lotilaner efficacy was 100% in preventing establishment of B. canis infection, despite post-treatment challenge with infected ticks on Days 2, 7, 14, 21 and 28. [ABSTRACT FROM AUTHOR]

Background: Lotilaner (Credelio™, Elanco), a novel isoxazoline, is a systemic insecticide and acaricide that is rapidly absorbed following oral administration to dogs and has a half-life of 30 days. As part of a development program, studies were undertaken to investigate lotilaner's initial and sustained efficacy and speed of kill against fleas. Methods: Four studies were conducted to evaluate the onset of lotilaner's speed of flea knockdown at the time of treatment, and to determine the sustained speed of flea kill (SOK) up to 35 days post-treatment. Each study assessed one or two specific time points (4, 6, 8 and 12 h) post-treatment and following weekly re-infestations. In each study, dogs were randomised to a lotilaner or an untreated group based on pre-administration flea counts, and before treatment were infested with adult Ctenocephalides felis. Dogs randomised to a lotilaner group received a single treatment on Day 0, at the minimum recommended dose rate of 20 mg/kg, 30 (± 5) minutes after being fed. Efficacy was calculated using geometric, and arithmetic mean flea counts in treated versus untreated groups. Results: On Day 0, lotilaner efficacy was 89.9% at 4 h, 99.2% at 6 h, 99.9% at 8 h, and 100% at 12 h post-treatment. At each weekly assessment, lotilaner efficacy at 4 h remained at > 97%, at 8 h remained at > 99%, and at 12 h remained at 100% through Day 35. Across all studies, there were no treatment-related adverse events. Conclusion: Lotilaner's rapid flea knockdown immediately following treatment and sustained SOK through 35 days post-treatment offers a new solution for helping to eliminate the health risks that accompany flea infestations on dogs. The consistency of the rapid, sustained flea SOK demonstrated in these studies generates confidence that monthly use of lotilaner in dogs can be valuable in disrupting the flea life cycle in a contaminated environment, and that newly acquired fleas will die quickly, thereby reducing the discomfort of flea bites. The sustained lotilaner SOK also provides confidence that there will be no "end-of-dose" resurgence in flea burdens with the potential accompanying consequence of flares in flea-bite hypersensitivity. [ABSTRACT FROM AUTHOR]

Background: Dirofilaria repens is the causative agent of subcutaneous dirofilariosis of dogs, other animals and humans. This nematode is transmitted by mosquitoes of Aedes, Anopheles and Culex genera. In dogs, the parasite may cause subclinical infection or cutaneous signs. Recently, D. repens has emerged and spread in different geographical areas, with an increase of cases in dogs and humans. Chemoprevention in dogs in endemic areas is the most reliable approach for controlling this infection. This paper describes a randomized, blocked and multicentric clinical field study investigating the efficacy of an oral, chewable formulation containing milbemycin oxime/praziquantel (Milbemax®, Novartis Animal Health) in the chemoprevention of subcutaneous dirofilariosis in dogs. Methods: This study was conducted in endemic areas of Italy. A total of 249 dogs, at two sites, negative for D. repens, were allocated into two groups (i.e. Treated -T1 vs Untreated-T2) with a ratio of 1:1, and subjected to clinical visits and blood sampling once monthly until the end of the study. All blood samples were microscopically and genetically examined. Animals belonging to T1 group received a minimum target dose of 0.5 mg/kg bodyweight of milbemycin oxime and 5 mg/kg of praziquantel in commercial tablets (Milbemax®) according body weight once every 4 weeks. Animals of group T2 were not treated with Milbemax® but received, when necessary, specific parasiticide treatments. The study duration was 336 ± 2 days for each dog. Results: A total of 219 dogs completed the study (i.e. 111 in T1 and 108 in T2), while 30 dogs (i.e. 13 in T1, 17 in T2) were withdrawn for a variety of reasons unrelated to administration of Milbemax®. The percentages of animals not showing microfilariae of D. repens were 100% (111 animals) in T1 and 94.7% (108 animals out of 114) in group T2. Milbemax® was shown to be safe in treated dogs. Conclusions: The results of this study confirm that the monthly use of Milbemax® in dogs is effective and safe for the prevention of subcutaneous dirofilariosis in endemic areas. [ABSTRACT FROM AUTHOR]

Background This survey was carried out to examine the experience and opinion of veterinarians with canine heartworm (HW; Dirofilaria immitis) infection in non-endemic and endemic areas of Europe and their awareness of ESCCAP Guidelines on HW prevention. Methods A questionnaire was distributed by e-mail to veterinary practitioners within non-endemic countries including UK, Germany, and Netherlands, non-endemic regions of France, Spain, Italy and endemic regions of France, Spain and Italy. The main questions were about the HW cases seen in the last 12 months, if the number of cases had changed over the last 5 years and how aware the practitioners were about the ESCAAP Guidelines on HW. Additional questions examined the perception of practitioners regarding the risk of HW for pets travelling in endemic areas and the use of preventatives including veterinary perception of pet owner compliance. Results Overall 584 responses, 389 from non-endemic countries and regions and 195 from endemic regions were obtained. Most of the cases were seen in endemic regions, although in Germany 20% of veterinarians reported cases of HW infection. Overall, 10% of practitioners in non-endemic areas and 12% in endemic areas, respectively, reported an increasing number of cases. The practitioner awareness of ESCCAP guidelines is low. Veterinarians responded that preventative drugs were prescribed to most client dogs in endemic areas and most practitioners rated owner compliance as good or excellent in following the veterinarian's guidance for HW prevention. Overall 63% of veterinarians responded that owners are more or less aware of the HW risk traveling with their dogs in endemic areas. Forty four percent of responders in non-endemic regions considered it somewhat likely to very likely that HW infection will become endemic in their regions. Conclusions Both in non-endemic and in endemic countries at least 1 responding practitioner admitted seeing a case of canine HW infection and has shown awareness regarding infection. Ten percent of practitioners stated that the number of cases is increasing. Although the number of owners traveling with their dogs was low, the perception of surveyed veterinarians was that owners were quite aware of the HW risk for their dogs. Several veterinary practitioners had the perception that HW infection could become endemic in their non-endemic area within the next 10 years. [ABSTRACT FROM AUTHOR]

Intestinal nematodes affecting dogs, i.e. roundworms, hookworms and whipworms, have a relevant health-risk impact for animals and, for most of them, for human beings. Both dogs and humans are typically infected by ingesting infective stages, (i.e. larvated eggs or larvae) present in the environment. The existence of a high rate of soil and grass contamination with infective parasitic elements has been demonstrated worldwide in leisure, recreational, public and urban areas, i.e. parks, green areas, bicycle paths, city squares, playgrounds, sandpits, beaches. This review discusses the epidemiological and sanitary importance of faecal pollution with canine intestinal parasites in urban environments and the integrated approaches useful to minimize the risk of infection in different settings. [ABSTRACT FROM AUTHOR]

These guidelines are intended to provide an in-depth review of current knowledge and assist the planning and implementation of studies for evaluating the efficacy of parasiticides in reducing transmission of vector-borne pathogens (VBPs) to dogs and cats. At present, the prevention of VBP transmission in companion animals is generally achieved through the administration of products that can repel or rapidly kill arthropods, thus preventing or interrupting feeding before transmission occurs. The present guidelines complement existing guidelines, which focus on efficacy assessment of parasiticides for the treatment, prevention and control of flea and tick infestations, but also give guidance for studies focused on other vectors (i.e. mosquitoes and phlebotomine sand flies). The efficacy of parasiticides in reducing VBP transmission can be evaluated through laboratory or field studies. As such, the present guidelines provide recommendations for these studies, representing a tool for researchers, pharmaceutical companies and authorities involved in the research, development and registration of products with claims for reducing VBP transmission in dogs and cats, respecting the overall principles of the 3Rs (replacement, reduction and refinement). Gaps in our current understanding of VBP transmission times are herein highlighted and the need for further basic research on related topics is briefly discussed. [ABSTRACT FROM AUTHOR]