Affiliation(s)
ABSTRACT
Loss of efficacy due to resistance development against anthelmintics in
livestock parasites is a growing concern worldwide. The aim of the present
study was to determine the efficacy of moxidectin, a frequently-used macrocyclic
lactone, against gastrointestinal nematodes of sheep in Austria. Individual
faecal samples were collected from 243 adult sheep from 16 flocks in Styria and
Salzburg before deworming and egg excretion (EPG (eggs per gram) of faeces) was
determined using a modified McMaster technique. The animals were randomly
assigned to a treatment group which received 0.2 mg/kg of body weight of
moxidectin (Cydectin®, Zoetis Schweiz GmbH, Zürich, Switzerland),
and an untreated control group. Fourteen days after deworming a FECRT (faecal egg count
reduction test) for detection of anthelmintic resistance was performed. Before
deworming, the infection rate for gastrointestinal strongylids was 94.7%, with
EPG values of 0~5,800. The FECRT showed
reduction rates between 93.08% and 99.78% and was sufficient in 15/16 flocks.
The lower confidence interval was 70.0~100%. In 3/16 flocks this value was below the minimum for sufficient
efficacy (70.0%, 79.0%, 85.0%), and in two
flocks the value (90.0%) was near the limit. These results indicated a
(suspected) reduced efficacy of moxidectin in 5/16 examined flocks.
KEYWORDS
FECRT (faecal egg count
reduction test), EPG (eggs per gram)
faeces, moxidectin, anthelmintic resistance.
Cite this paper
Schoiswohl, J., et al. 2017. “Suspected Resistance against Moxidectin in Sheep Strongylid Nematodes in Austria.” Journal of Pharmacy and Pharmacology 5 (3): 109-117.
References