Prevalence, risk factors and economic impact of sheep coccidiosis in the Canary Islands: a preliminary approach

Abstract

Eimeria spp. is a group of protozoa, monoxenous and intracellular parasites of the gastrointestinal track of mammals and birds which are species-specific. Coccidiosis in ruminants, depending on the mode of management, may affect 100% of the animals of the herds and cause severe economic losses by affecting animal health and profitability. In particular, ovine coccidiosis due to Eimeria spp. has been poorly studied: there no data from the Canary Islands and those of mainland Spain are scarce. The goal of this study has been to investigate the prevalence of ovine coccidiosis in farms from Gran Canaria island and to identify, by using questionnaire, risk factors and the economic impact of this parasitic disease. For this purpose, faecal samples were taken from seven different farms for individually parasite quantification (oocyst per gram of faeces) and further identification of the different ovine Eimeria species. Both adult sheep and lambs were included in the study. Farmers and their respective farm’s veterinarians were surveyed in person to acquire information about each specific farm: characteristics, environmental and management conditions, to properly interpret the parasitological results. The overall results of the present study show that Eimeria spp. were found in all the 7 farms sampled, with E. weybridgensis/crandallis being the most prevalent among all eleven species identified. The parasite’s prevalence was variable, but consistent, reaching almost 70% of all samples studied in adults and close to 100% in lambs. Clearly, the level of infection for lambs was much higher than in adults in all farms, but clinical signs of coccidiosis were barely appreciated in both age groups. Some management conditions were found to be correlated to parasitological data, such as the size of the farm, the rearing system or the used of anticoccidials. Interestingly, awareness of farmers about coccidiosis and parasitic diseases in general was poor in contrast to the high prevalence and associated costs reported, which could be a risk factor for the improvement of control strategies against ovine coccidiosis. Further studies are need to increase sampling and questionnaires in order to get more consistent conclusions for the development of effective management strategies against ovine coccidiosis, including the prevention of anticoccidial resistance.