Anthelmintic (dewormer) resistance is a worldwide problem and growing, not just in sheep and goats, but also cattle. The fecal egg count reduction test (FECRT) is currently the only method for determining anthelmintic resistance at the farm level.
Because of the cost and labor associated with fecal egg counting (FEC), it is rarely performed on farms, unless it is for research purposes. One approach to reducing the cost of the FECRT is the use of pooled composite samples for performing fecal egg counts, rather than conducting FEC on 15-20 individual animals.
Researchers at the University of Georgia conducted a study with 14 groups of cattle to compare the results of composite sampling versus individual sampling. Results of the study are published in the current issue of Veterinary Parasitology. The article also describes methods for conducting composite sampling.
There was little difference between the approaches with 98% agreement in mean fecal egg count found between the methods. There was greater than 95% agreement in drug efficacy between the composite and individual samples. The data demonstrated that pooling fecal samples from a group of cattle and then performing repeated FEC on that composite sample yields very similar results compared to performing individual FEC on those same animals, while substantially reducing the cost of performing a FECRT.
Read article in Vet. Parasit. Volume 240. June 2017