Lymphocytic enteritis and systemic vasculitis in sheep.

Lymphocytic enteritis and systemic lymphocytic vasculitis may be a new or previously unrecognized syndrome in sheep suffering from chronic wasting. Seven cases in three separate flocks were seen over an eight-year period at Veterinary Laboratory Services in Brighton, Ontario. Most of the animals were between five and twelve months of age and exhibited weight loss and inappetance, with or without diarrhea. All were Suffolks or crossbred Suffolks. In one of the flocks, there were also several sheep with lymphoma. Postmortem examination of carcasses and ancillary testing did not reveal an etiology; however, the intestinal and vascular lesions resembled those described in certain viral diseases, such as malignant catarrhal fever and Border disease, and immune-mediated diseases, such as polyarteritis nodosa. Submission for necropsy of sheep that exhibit signs of chronic wasting is encouraged, to help establish the etiology of the disease and its significance to the industry.