Viral Infections and Respiratory Disease in Dairy-Bred Calves

Abstract

After salmonellosis respiratory disease probably remains the most important condition of market purchased dairy bred calves. Treatment rates for respiratory disease have been found to exceed 30% during the first three months of the rearing phase (1) and this disease is therefore responsible for significant losses in terms of animal performance, veterinary costs and labour irrespective of the implications for the welfare of the young calf.

The association between respiratory virus infection and clinical respiratory disease has been demonstrated in weaned beef calves and in home reared dairy calves, but in calves less than three months of age there was little evidence of viral involvement (2 and 3). However disease monitoring on one calf rearing unit led to the observation that despite good response to antibiotic therapy, the outbreaks of sudden onset high morbidity respiratory disease seen in calves less than three months of age, had a possible viral aetiology. To explore this further the following study was carried out.