Non-systemic erosive stomatitis of unknown aetiology in a dairy cow herd in New Zealand

CASE HISTORY: Veterinarians from the Investigation and Diagnostic Centre (IDC), Wallaceville, New Zealand, investigated a novel vesicular disease in a 397-cow dairy herd, characterised by erosive stomatitis. CLINICAL AND PATHOLOGICAL FINDINGS: The investigation commenced with a report of erosive stomatitis in four dairy cows. The herd was examined that day and 30/397 (8%) adult cows were found to be affected. Two weeks later, the oral cavity of 180 cows from one management group were re-examined, and it was estimated that 80% of this group had healing erosive lesions. During the course of the investigation, intact vesicles were observed on the muzzle of two affected animals. None of the affected animals was systemically ill and there was no decrease in milk production. DIAGNOSIS: No infectious aetiological agent was detected using virus isolation, polymerase chain reaction (PCR), electron microscopy (EM) and serological tests, for any exotic infectious vesicular disease or any endemic cause of vesicular disease. CLINICAL RELEVANCE: Lesions of erosive stomatitis occurring in cattle must be differentiated from vesicular disease during exotic disease investigations.