Effects of treatment with ivermectin for five years on the prevalence of Anoplocephala perfoliata in three Louisiana pony herds
French, D.D.; Chapman, M.R.; Klei, T.R.
Veterinary Record 135(3): 63-65
1994
ISSN/ISBN: 0042-4900 PMID: 7975087 Document Number: 428816
The prevalence of A. perfoliata infection in 3 herds of 12-16 pony mares and their foals was recorded for 5 years. One herd received no anthelmintics, the second received ivermectin at regular intervals and the third received ivermectin, pyrantel pamoate, oxibendazole and thiabendazole-piperazine in rotation. Faecal samples were collected every 2 or 4 weeks during the study and the number of eggs per gram (epg) determined. Some foals, during the study, and some mares, at the end of the study, were examined PM and their parasite burden assessed. At the end of the study 7 of the ivermectin treated and 7 untreated mares were treated with pyrantel pamoate which is known to be effective against A. perfoliata. Analysis of the epg data from the mares indicated that there were significantly more positive samples and animals in the ivermectin-treated herd than in the untreated herd. However, the parasite burden data from the foals and the pyrantel pamoate treated mares showed no significant differences between the groups. It is concluded that 5 years on ivermectin treatment did not promote an increase in A. perfoliata in the mares or their foals; moreover, the ivermectin treatment was highly effective against all nematode parasites in these horses. It is suggested that pyrantel pamoate should be included in rotational anthelmintic programmes to reduce tapeworm burdens.