Canadian research conducted by John Ellis, veterinarian at the Western College of Veterinary Medicine in Saskatchewan, shows a significant reduction in clinical signs of bovine respiratory syncytial virus (BRSV) in young calves vaccinated against the disease.

In the study of 17 colostrum-fed calves, eight were vaccinated with a killed virus vaccine at nine weeks of age, followed by a second shot three weeks later. At 15 weeks of age, all calves were challenged with a virulent disease-causing strain of BRSV.

"Results from the study reveal vaccinated calves had a significant reduction in clinical signs and lung lesions compared to the non-vaccinated calves," says Myron Brown, veterinarian and manager of large animal veterinary professional services for Merial. Additionally, six of the nine non-vaccinated calves died during the trial, while none of the vaccinated animals did. Necropsies of all the calves found that 51 percent of the lung tissue in the non-vaccinated calves contained pneumonic tissues, with vaccinated calves having just 2.28 percent pneumonic tissue.

This study suggests that vaccinating calves for BRSV with a commercially-available killed BRSV vaccine is an important tool in fighting respiratory problems.