Multicentric schwannomas causing chronic ruminal tympany and forelimb paresis in a Holstein cow.

A nine-year-old Holstein cow that developed recurrent ruminal tympany and an abnormal forelimb gait and posture ultimately became recumbent and unable to rise, and was euthanased. A postmortem examination demonstrated numerous schwannomas affecting peripheral nerves and several thoracic and abdominal viscera.

Chronic hepatitis associated with leptospiral infection in vaccinated beagles.

Sixteen juvenile Beagle dogs originating from a single breeding colony and regularly vaccinated against Leptospira interrogans (serogroups Canicola and Icterohaemorrhagiae) developed a clinical syndrome characterized by retarded growth, weight loss and often ascites. Over a 10-month period, post-mortem examinations were performed on all affected dogs. Gross lesions were confined to the liver which was often firm, tan-coloured and mottled. Microscopically, hepatic lesions ranged from those of severe chronic hepatitis to mild diffuse hepatocellular vacuolation, with bile stasis, occasional scattered lymphocytic aggregates and haemosiderin granulomas. Special stains and electron microscopy revealed spirochaetes within bile canaliculi. The genus Leptospira was recognized by immunohistochemical methods in nine dogs. Leptospires were isolated from six dogs, but serological tests failed to detect significant titres of antibody to L. interrogans in these animals. A serological survey of 37 kennelmates demonstrated that 20 dogs had high titres of serogroup Australis leptospiral antibody, which could not have resulted from vaccination. These findings strongly suggest a connection between the presence of leptospires and the hepatic lesions.