Anaemia, diarrhoea and opportunistic infections in Fell ponies

This report summarises clinical and pathological observations on Fell pony foals with a range of signs that included ill thrift, anaemia, respiratory infection, glossal hyperkeratosis and diarrhoea. Some of the foals had norm ochromic, normocytic anaemia and some had low levels of plasma proteins, in cluding immunoglobulin G. Antibiotic and supportive treatment was ineffecti ve and all affected foals died or were killed on humane grounds. Postmortem examination of 12 foals and tissues from 2 other foals revealed a range of lesions that included glossal hyperkeratosis, typhlocolitis, intestinal cr yptosporidiosis, granulomatous enteritis, proliferative and necrotising bro nchiolitis consistent with adenovirus infection; lesions similar to those i n the respiratory tract were present in the salivary gland and pancreas of individual foals. Lymphoid tissue was judged to be smaller than expected, T hese observations suggest the possibility of opportunistic infections secon dary to some form of undefined immunocompromised state.