FOAL DIARRHEA BETWEEN 1991 AND 1994 IN THE UNITED-KINGDOM ASSOCIATED WITH CLOSTRIDIUM-PERFRINGENS, ROTAVIRUS, STRONGYLOIDES WESTERI AND CRYPTOSPORIDIUM SPP

A case control study of foal diarrhoea in the United Kingdom was carri ed out over a 3-year period. Clostridium perfringens was significantly associated with foal diarrhoea (Odds Ratio (OR) = 3.0), being isolate d from 57% of 421 animals with diarrhoea but from only 27% of 223 heal thy foals. Also, C. perfringens was significantly associated with fata l diarrhoea (OR = 4.5). About half of diarrhoea with a fatal outcome w as attributable to this organism. The other pathogens significantly as sociated with diarrhoea were rotavirus (OR = 5.6), Cryptosporidium spp . (OR = 3.2) and the nematode Strongyloides westeri, which was signifi cant only when present in large numbers (> 2000 eggs/g of faeces: OR = 6.1). Salmonella spp. (OR = 14.2) and Cryptosporidium spp. (OR = 3.0) were the only other pathogens associated with fatal illness. Overall, C. perfringens, rotavirus, and large numbers of Cryptosporidium spp. or S. westeri were isolated from 80% of foals with diarrhoea. Thermoph ilic Campylobacter spp., Yersinia enterocolitica, Escherichia coli and other parasites were not associated with diarrhoea. Carriage of C. pe rfringens, rotavirus and Cryptosporidium spp. was significantly greate r in healthy foals in contact with cases of diarrhoea than in foals th at were not in contact with diarrhoea (P < 0.05). There were no statis tical interactions between any of the pathogens associated with diarrh oea although separate cases from one location often involved more than one pathogen.