Corynebacterium equi Infections in Horses, 1958-1984: A Review of 131 Cases

Of 131 cases of Corynebacterium equi infection in horses submitted for necropsy to the Ontario Veterinary College or Veterinary Laboratory Services, OMAF, Guelph, Ontario from 1958 to 1984, 115 were diagnosed as suppurative pneumonia, and of these 55 had associated ulcerative enterocolitis. Only five animals had intestinal involvement without pulmonary lesions. The remaining 11 cases included arthritis/cellulitis, skin abscesses and submandibular lymphadenitis. While the lung, intestine and associated lymph nodes yielded C. equi most frequently, in 21% of cases C. equi was also cultured from parenchymatous organs (spleen, liver or kidney) or blood. Corynebacterium equi infection accounted for 10% of all foals submitted for postmortem examination and 45% of all foals with pneumonia. Affected foals were one to four months of age. Submissions occurred between the months of May and August with a peak during July. There was a significantly greater prevalence of C. equi infection in Standardbreds when compared with other breeds. Of foals in this study, 36% were from farms which had had other horses succumb to this disease. Of the foals with pulmonary involvement, 21% did not have fever or clinical signs referable to the respiratory or gastrointestinal systems, findings which indicated that a large percentage of cases were subclinical.     

Cerebellar disease in an adult cow

This is the report of clinical signs and lesions of a cerebellar disorder in an adult four year old Limousin cow grazing perennial ryegrass (Lolium perenne). The most striking histopathological lesion was a marked paucity of Purkinje cells throughout the cerebellum.     

A Field Trial of a Pilated Moraxella bovis Bacterin for the Prevention of Infectious Bovine Keratoconjunctivitis

Two field trials were conducted to evaluate the efficacy of a Moraxella bovis bacterin in the control of infectious bovine keratoconjunctivitis. The bacterin did not affect the incidence of infectious bovine keratoconjunctivitis in either trial but did appear to reduce the severity of lesions, treatments required and withdrawals from pasture required in one trial. Possible reasons for the apparently contradictory results are offered. It is suggested that the bacterin may be of some value when used in conjunction with other preventive measures.