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In June 2022, at the XXXII Conference of the Italian Society of Parasitology, the parallels of the main endoparasitic infections of horses and donkeys were discussed. Although these 2 species are genetically different, they can be challenged by a similar range of parasites (i.e. small and large strongyles, and Parascaris spp.). Although equids can demonstrate some level of resilience to parasites, they have quite distinct helminth biodiversity, distribution and intensity among different geographical locations and breeds. Heavily infected donkeys may show fewer clinical signs than horses. Although parasite control is primarily provided to horses, we consider that there may be a risk of drug-resistance parasitic infection through passive infection in donkeys when sharing the same pasture areas. Knowing the possible lack of drug efficacy (<90 or 80%), it is advocated the use of selective treatment for both species based on fecal egg counts. Adult horses should receive treatment when the threshold exceeds 200–500 eggs per gram (EPG) of small strongyles. Moreover, considering that there are no precise indications in donkeys, a value >300 EPG may be a safe recommendation. We have highlighted the main points of the discussion including the dynamics of helminth infections between the 2 species.

Intestinal strongyles are the most common endoparasites of horses, and anthelmintic treatments are the main strategy to control these nematodes. However, the development of anthelmintic resistance has led to a decreased efficacy of synthetic drugs, and for this reason, there is a growing interest in alternative control strategies as the use of medicinal plants. The aim of the present study was to determine the in vivo efficacy of garlic (Allium sativum) in horses naturally infected by intestinal strongyles. The field trial was conducted in a horse trotter farm in Southern Italy. Fifteen mares were selected based on fecal egg count >200 eggs per gram and allocated into three groups of five animals: fresh garlic group (FG group), animals received 40 g of fresh crushed garlic once daily for 15 days; dry garlic group (DG group), animals received 40 g of commercial dry garlic flakes food supplement once daily for 15 days; and control group (C group), not treated. Two weeks after the first administration of garlic, fecal egg count reduction test showed failure of garlic to reduce intestinal strongyles egg shedding (-11.7% and -19.4% for FG and DG groups, respectively). Red blood cell count values were in the normal ranges over the entire period of garlic administration. In our study model, the oral administration of garlic formulations has no effect on reducing the egg shedding of intestinal strongyles, and the garlic supplementation over a short period of time is not responsible for hematological changes in horses., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To investigate plasma disposition, concentration in the hair, and anthelmintic efficacy of eprinomectin after topical administration in donkeys., Animals: 12 donkeys naturally infected with strongyle nematodes., Procedures: The pour-on formulation of eprinomectin approved for use in cattle was administered topically to donkeys at a dosage of 0.5 mg/kg. Heparinized blood samples and hair samples were collected at various times between 1 hour and 40 days after administration. Samples were analyzed via high-performance liquid chromatography with fluorescence detection. Fecal strongyle egg counts were performed by use of a modified McMaster technique before and at weekly intervals for 8 weeks after treatment., Results: Plasma concentration and systemic availability of eprinomectin were relatively higher in donkeys, compared with values reported for other animal species. Concerning the anthelmintic efficacy against strongyle nematodes, eprinomectin was completely effective (100%) on days 7 and 14 and highly effective (> 99%) until the end of the study at 56 days after treatment. No abnormal clinical signs or adverse reactions were observed for any donkeys after treatment., Conclusions and Clinical Relevance: Eprinomectin had excellent safety. The relatively high plasma concentration after topical administration could result in use of eprinomectin for the control and treatment of parasitic diseases in donkeys.

A trial to assess the efficacy of eprinomectin (EPM) against the lungworm Dictyocaulus arnfieldi was carried out on 15, naturally-infected donkeys. Ten animals were treated with a 'pour-on' EPM preparation (at a dose of 0.5 mg/kg bodyweight), and five animals acted as controls. Faecal larval counts were carried out two days before treatment, on day of treatment and 7, 14, 21 and 28 days post-treatment with the anthelmintic. EPM was 100% effective in eliminating faecal larvae from day 7, until the end of study at day 28. No adverse drug-reactions or side-effects were observed in any of the treated donkeys., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

The aim of the present paper was to assess the benefit of targeted selective treatments (TSTs) on milk production and faecal worm egg count, in four commercial dairy sheep farms in southern Italy where animals were exposed to natural infection with gastrointestinal (GI) strongyles. On each farm, three similar groups of 20 animals each were formed and randomly assigned to the following treatments: strategic prophylactic treatment (SPT) group, targeted selective treatment group, and control (C) group. The TST schemes used were different between farms with regard to the indicators for treatment (FAMACHA or faecal egg count (FEC) or milk production) and the timing of treatment (periparturient or postparturient). Regarding milk production, on the four study farms the mean daily milk production in the SPT ewes was higher than those of the controls on Farms 1, 2, 3 and 4 by 13.6%, 30.4%, 37.0% and 5.5%, respectively. In the case of Farms 2 and 3 these differences were significant (P<0.05). Average milk production in the TST ewes was higher than that in the control group, by 7.2% in Farm 1; 10.1% in Farm 2; 13.0% in Farm 3; and 1.4% in Farm 4; however, none of these differences were statistically significant. Regarding the effects on FEC, FAMACHA-based TST (Farms 1 and 2) had no positive effects on GI strongyle egg counts. In the FEC-based TST group on Farm 3 both the TST and SPT treatments reduced FEC. In the milk production-based TST group (Farm 4), no conclusion could be drawn regarding strategic efficacy since there was also a decrease in GI strongyle FEC in the control group. The findings of the present study demonstrate that TST can be considered as a potentially useful anthelmintic strategy in southern Italy, but the timing of treatments seems to be more crucial for the strategic and production efficacy than the indicators used for those treatments. From a practical point of view using milk production as a TST indicator appeared to be the most user-friendly approach for farmers; however, further studies will be needed to confirm its validity and acceptability.

The pharmacokinetics and mammary excretion of moxidectin and eprinomectin were determined in water buffaloes (Bubalus bubalis) following topical administration of 0.5mgkg(-1). Following administration of moxidectin, plasma and milk concentrations of moxidectin increased to reach maximal concentrations (C(max)) of 5.46+/-3.50 and 23.76+/-16.63ngml(-1) at T(max) of 1.20+/-0.33 and 1.87+/-0.77 days in plasma and milk, respectively. The mean residence time (MRT) were similar for plasma and milk (5.27+/-0.45 and 5.87+/-0.80 days, respectively). The AUC value was 5-fold higher in milk (109.68+/-65.01ngdayml(-1)) than in plasma (23.66+/-12.26ngdayml(-1)). The ratio of AUC milk/plasma for moxidectin was 5.04+/-2.13. The moxidectin systemic availability (expressed as plasma AUC values) obtained in buffaloes was in the same range than those reported in cattle. The faster absorption and elimination processes of moxidectin were probably due to a lower storage in fat associated with the fact that animals were in lactation. Nevertheless, due to its high excretion in milk and its high detected maximum concentration in milk which is equivalent or higher to the Maximal Residue Level value (MRL) (40ngml(-1)), its use should be prohibited in lactating buffaloes. Concerning eprinomectin, the C(max) were of 2.74+/-0.89 and 3.40+/-1.68ngml(-1) at T(max) of 1.44+/-0.20 and 1.33+/-0.0.41 days in plasma and milk, respectively. The MRT and the AUC were similar for plasma (3.17+/-0.41 days and 11.43+/-4.01ngdayml(-1)) and milk (2.70+/-0.44 days and 8.49+/-3.33ngdayml(-1)). The ratio of AUC milk/plasma for eprinomectin was 0.76+/-0.16. The AUC value is 20 times lower than that reported in dairy cattle. The very low extent of mammary excretion and the milk levels reported lower than the MRL (20ngml(-1)) supports the permitted use of eprinomectin in lactating water buffaloes.

The present paper was aimed at assessing the benefit of strategic anthelmintic treatments on milk production in four commercial dairy sheep farms in Southern Italy whose animals were naturally infected by gastrointestinal (GI) strongyles and Dicrocoelium dendriticum. The scheme was based on two treatments timed in relationship to parturition, i.e. the first with moxidectin in the periparturient period and the second with netobimin at the mid/end of lactation. On each farm, two similar groups (20 animals each) were formed, one untreated control group and one group treated according to the above-mentioned scheme. Faecal egg counts (FEC) were performed on each study animal at the start of the trial and then monthly until the end of the study; in addition, milk production was recorded for each animal fortnightly in each farm for the lactation period. The results showed a significant increase in milk yield across all four farms that ranged from 19% to 44% improvement in milk yield. The benefit in milk yield in addition to considerably reduced egg output of the treated animals provide clear evidence that the two main aims of prophylactic parasite control, i.e. to maintain or improve animal performance and to reduce pasture contamination, can be achieved using strategic anthelmintic treatments.

Triclabendazole is the current drug of choice against Fasciola spp. infections in livestock, but resistance has become a major problem. In this study, we assessed the efficacy and safety of artemether, a derivative of artemisinin, in sheep with a low natural Fasciola hepatica infection. Artemether was administered orally or intramuscularly; sheep were monitored for 8 h posttreatment and then once daily for adverse events, and drug efficacy was estimated by fecal egg count reductions and worm burden reductions. Single 40- and 80-mg/kg oral doses of artemether showed no effect on F. hepatica egg and worm burden. Treatment with a single 160-mg/kg intramuscular dose of artemether significantly reduced the egg burden (64.9%) and worm burden (91.3%). At half this dose, a worm burden reduction of 65.3% was obtained, which was still statistically significant (P < 0.05). The lowest intramuscular dose of artemether investigated (40 mg/kg) yielded no effect on egg counts and worm burden. There were no adverse events due to artemether; however, two abortions were observed 7 days posttreatment. In conclusion, artemether shows interesting fasciocidal properties in sheep, but embryotoxicity is of concern. Further studies are warranted to assess the potential of additional artemisinin derivatives and other peroxidic compounds for the treatment of Fasciola spp. infections in different ruminants.

The aim of the present paper was to assess benefit of strategic anthelmintic treatments on milk production in six commercial dairy sheep farms, located in southern Italy, whose animals were naturally infected with gastrointestinal strongyles. On each farm, two similar groups were formed, one untreated control group and one treated group. In all the treated groups, the strategic anthelmintic schemes were based on: (i) only one treatment with moxidectin in the periparturient period (February, Farm No. 6), or; (ii) two treatments, i.e. the first with moxidectin performed in the periparturient period (February, Farms Nos. 1, 2, 3 and 4) or in the postparturient period (April, Farm No. 5), and the second with netobimin at the mid/end of lactation (June, Farms Nos. 1, 2, 3, 4 and 5). Faecal egg count reduction (FECR) tests were performed on each farm in order to asses the anthelmintic efficacy of the drugs used. In addition, milk yield measurements for each animal fortnightly in each farm for the lactation period were performed. In terms of FECR, both moxidectin and netobimin were effective in all the 6 studied farms. Regarding milk production, overall in the 6 study farms the mean daily milk productions of the treated groups were higher than those of the control group. However, there were important differences between the 6 farms, i.e. the increase of milk production in the treated groups versus the control groups was as follows: +18.9% (Farm 1), +30.4% (Farm 2), +4.0% (Farm 3), +37.0% (Farm 4), +5.5% (Farm 5) and +40.8% (Farm 6). The results of the study showed that the economic efficacy of an anthelmintic treatment is not a cause-effect issue, but is a multifactorial issue which depends upon the quali-quantitative parasitological status of the animals, the pathogenesis of the species of parasites, the virulence of the strains of parasites, the local epidemiology, the timing of treatment, the breed of animal in terms of genetics and production types, nutrient supply.

Anthelmintic resistance is widely distributed in small ruminants throughout the world. The extension of resistance seems lower in southern European countries and has not been reported previously in Italy. In the present study, resistance to benzimidazoles, levamisole and ivermectin was evaluated in a multi-breed goat farm of southern Italy. The farm had a history of repeated goat introductions from other flocks and a moderate regimen of anthelmintic treatments using alternatively the three above-mentioned drugs. Resistance of gastrointestinal strongyles was studied on the basis of faecal egg counts, egg hatch assay and necropsies. Resistance to anthelmintics was evidenced for benzimidazoles only, and Trichostrongylus colubriformis was the only resistant strongyle species. Single drug and single species resistance suggest that resistance is on its beginning and that measures for reducing the spread of resistance are of interest and should be promoted.

The distribution of eprinomectin in goat milk and cheeses (cacioricotta, caciotta, caprilisco) with different ripening times following a pour-on administration at a single dose rate (500 microg/kg of body weight) and a double dose rate (1,000 microg/kg of body weight) to goats with naturally occurring infections of gastrointestinal nematodes was studied. Milk residues of eprinomectin reached a maximum of 0.55+/-0.18 microg/kg and 1.70+/-0.31 microg/kg at the single and double doses, respectively. The drug concentrations decreased progressively until the fifth day after treatment, when they were less than the detection limit at both dose rates. The eprinomectin levels measured in all cheese types (both treatments) were higher than those recovered in milk at all the sampling times. In caciotta cheeses, the eprinomectin residues levels were constantly higher than other cheeses. With the exception of cheeses made with milk the first day after treatment, eprinomectin concentrations were nearly constant up to the fourth day then decreased by the fifth and sixth days after treatment. In all cases, at both the single and double dosages, the maximum level of eprinomectin residues in goat milk and cheeses remained below the maximum residual level of 20 microg/liter permitted for lactating cattle.

Gastrointestinal (GI) parasitism are the most serious problem affecting sheep and goats worldwide. Economic losses caused by GI strongyles are related to decreased production, costs for treatment and prophylaxis and animal death. Effective control of internal parasites in small ruminants is one of the most difficult challenges encountered by veterinary in practice. For control of helminth parasites in grazing animals it is important knowledge of epidemiology of the parasite as it interacts with the host in a specific climatic, management and production environment. Sheep and goats are infected by many of the same GI nematodes, but feeding and management practices alter levels of parasitism between the two ruminants. The most commonly anthelmintics used for helminth control in small ruminants include three chemical groups: Imidazothiazoles/Pyrimidines (Im/Pm), Benzimidazoles/Probenzimidazoles (Bz/Pbz) and Macrocyclic Lactones (ML). The control of gastrointestinal strongyles infections in goats shows specific patterns. The use of anthelmintics in goats is based upon anthelmintics goats-suited dose rates taking into account the specific pharmacokinetics features of some anthelmintics in this species. Several types of control strategies: deworming programs, grazing management, biological control, supplementary feeding and breeding approaches are discussed.

A study was carried out in Southern Italy on 90 Siriana breed goats with naturally occurring infections of gastrointestinal nematodes. Six similar groups of 15 goats were formed, one untreated control group and five groups treated once with ivermectin (I treatment) and once with netobimin (II treatment) at different times. Daily milk volume (mL) was recorded fortnightly for each animal for the whole lactation period. All the treated groups showed a total milk production that was statistically higher than that of the control group, and four of these groups showed at least one fortnightly measurement in which differences from the corresponding values of the control group were statistically significant. The best treatment timing seemed to be October-May, followed by February-June, December-May, and February-May. [ABSTRACT FROM AUTHOR]