Infectious Bovine Rhinotracheitis, commonly called IBR or “Red Nose” is a highly contagious virus disease of cattle. The causative agent of IBR is Bovine Herpesvirus-1 (BHV-1). IBR is recognized as one of the major cattle diseases of economic importance. This herpes infection has been linked to Shipping Fever in feedlot and back grounded cattle, reproductive failure, and neurological damage. Cattle of all ages that have not been vaccinated are susceptible to IBR infection.
IBR has a worldwide occurrence and 10-50% of cattle may be carriers of the virus depending on the herd’s vaccine status. If an infection starts in a herd or group of cattle, it may cause illness in 20-30% of unvaccinated animals. The death rate is low (1-5%) in uncomplicated cases. Spread of the virus is through direct contact with an infected animal. The reproductive form of the virus can be spread during mating. Risk factors that increase the transmission include a high rate of unvaccinated animals, crowding, and unsteady weather in the fall months.
IBR can manifest in multiple forms. The most common and most economically important is its association with Shipping Fever. It is often implicated as an infection which initiates the shipping fever complex 3-6 weeks after starting on feed. The virus diminishes the body’s ability to eliminate bacteria and other viruses and therefore the animal develops pneumonia. These animals generally first show a red nose and eye appearance. They develop a fever, become inappetent, and have trouble breathing. They typically stand with their head and neck extended when breathing with or without their tongue extended. These animals tend to stay bright and alert.
IBR plays a vital role in decreased fertility rates in a cow herd. Shortly after infection, cows and bulls can develop a genital disease manifested as swelling and pain. The cow herd may show some signs of red nose and eye, with or without evidence of pneumonia. These animals will often have sores in the middle of the eyes that closely resemble “Pink Eye.” Abortions occur several weeks after infection, usually at 6-8 months of gestation. The infection in calves 4-6 months of age may result in infection of the brain, known as meningitis.
A diagnosis of uncomplicated IBR can be established on history and physical exam. However, the diagnosis should be confirmed through a laboratory via nasal swabs. With pneumonia, it is important to remember that IBR may be just one component of the problem.
Treatment for IBR is symptomatic as there are no antiviral products available. At Twin Valley Veterinary Health Services, we recommend treating affected animals with a broad spectrum antibiotic to minimize secondary bacterial infections. Such antibiotics include Resflor, Draxxin, Nuflor, Excenel, and Micotil. During an outbreak, sick animals should be identified and isolated. New entries into the feedlot or group of cattle are advised against. Any animals that are not sick and have not been vaccinated, need to be vaccinated in the face of an outbreak.
Since IBR is common and highly contagious, control through vaccination is essential. At Twin Valley VHS, we recommend that all calves be vaccinated a 3 months of age and again at weaning for IBR. Any yearlings that are being back grounded, put in a feedlot, or being used as replacement heifers or bulls should also be vaccinated. All cows and bulls need to be vaccinated on an annual basis.
If you have any questions regarding the above information or any questions/concerns in general, please contact Twin Valley VHS at 745-6642.
Dr. Justin Noble DVM
Twin Valley Veterinary Health Services