Otitis media in dairy calves: a retrospective study of 15 cases (1987 to 2002)

Epidemiological data, clinical signs, complementary examination findings, antimicrobial treatments, and outcome were reviewed in 15 calves diagnosed with otitis media at the Centre hospitalier universitaire vétérinaire de l'Université de Montréal between 1987 and 2002. Age at presentation ranged from 2 to 18 weeks. A purulent ear discharge and epiphora were seen in 8/12 and 6/15 cases, respectively. Neurological signs observed were head tilt (13), eyelid ptosis (7), paresis/paralysis of the pinna (8), ataxia (2), strabismus (2), and convulsions (1). Concurrent pneumonia was frequently diagnosed (n = 11). A Mycoplasma sp. was the principal pathogen isolated from ear discharge; 6 out of 6 samples submitted were positive for mycoplasma. Tympanic bullae radiographs were considered abnormal in 12 out of 13 cases. Cerebrospinal fluid analysis was considered abnormal in 2 out of 5 cases. The antibiotic most commonly used was enrofloxacin (n = 7). Average treatment duration was 19.6 days. Four out of 8 treated animals for which follow-up information was available completely recovered. These results suggest that M. bovis is a major pathogen of otitis media in dairy calves and effective antimicrobial therapy should be of long duration.