Perceptions and interventions concerning coccidiosis in Dutch sheep farms

Coccidiosis in sheep is a protozoan disease of young lambs that is not yet fully understood, and its control still largely relies on the use of coccidiostats, despite development of resistance. It is hypothesized that in the Netherlands a proper diagnosis is not always made before treatment is initiated, possibly leading to an overuse of coccidiostats. The aims of this study are to investigate the perceptions and interventions of Dutch sheep farmers and their veterinarians regarding coccidiosis, with special attention to treatment and the use of anticoccidial drugs. An online survey was completed by 114 sheep farmers and 57 veterinary practitioners. The surveyed sheep farmers appeared to be genuinely interested in coccidiosis, with three-quarters considering it an important problem in their flock. Seventy per cent of the sheep farmers and 84 % of the veterinarians reported diarrhoea as the most important symptom of coccidiosis. Almost three-quarters of sheep farmers conducted faecal examination during the two preceding years, 87 % per cent have performed treatments, and half of them used coccidiostats annually. There was a wide variety of treatment approaches. Standard treatment of lambs without any clinical indication, or before 4 weeks of age, and treatment of adult sheep were reported by 26 %, 13 %, and 13 % of responding farmers, respectively, and the latter two are considered as incorrect treatments. In contrast, veterinarians estimated that, on average, coccidiostats are prescribed on 30 % of sheep farms in their practice, with treatment primarily based on clinical signs and faecal examination results. Potential obstacles to a correct diagnosis included practical difficulties in collecting faecal samples, and additional costs. Remarkably, questionable treatments were common, including treatments without a history of coccidiosis, treatments of lambs younger than one month of age and treatments of adult sheep. Although correct dosage of coccidiostats is crucial, 43 % of veterinarians advised dosing based on the heaviest animals, while in most cases weight was visually estimated by both farmer and veterinarian. Unfortunately, treatments were frequently applied without a proper diagnosis, and the applied dosage was often not correct, which may lead to unnecessary and incorrect use of coccidiostats resulting in an increased risk of resistance development. Since veterinarians are regarded as the most important advisors, they play a key role in the solution. By supporting veterinarians, preventive measures and more prudent use of coccidiostats can be promoted.