(Red Nose, Necrotic rhinitis) Infectious Bovine Rhinotracheitis (IBR) is an acute contagious viral disease of cattle characterised by fever, rhinitis, dyspnoea, meningo-encephalitis, kerato-conjunctivitis, vulvo-vaginitis and abortion. Disease is widely prevalent and reported from almost all parts of the world. Cattle of all ages are affected and it is reported from wild ruminants, goat, swine and water buffaloes. Bovine Herpes Virus-1 (BHV – 1) is the causative agent and this RNA virus is stable at a pH of 6.9. Virus is susceptible to lower pH, ether, acetone and alcohol. This virus is antigenically related to Equine rhinopneumonitis virus and can be cultivated in calf kidney, skin and testis cell cultures. Disease is usually transmitted through infected feed and water. Virus can be spread through ocular, nasal, vulval discharge and other excretions of the infected cattle. Droplet infection is the main mode of transmission. Transmission through semen is possible. Latent infection is possible and reactivation of virus is possible in stress conditions. Stress during parturition, infestation with Dictyocaulus viviparous, Se and Zn deficiency predisposes. Pathogenesis: virus multiplies in the upper respiratory tract and cause rhinitis, laryngitis and tracheitis. Lesions may extend to eyes through nasolacrymal duct and may give rise to conjunctivitis. It will produce meningoencephalitis if infection spread through trigeminal nerve. Changes in placenta and foetus cause abortion. Clinical signs 1. Respiratory form: Rise in temperature, anorexia, respiratory difficulty, mucopurulent discharge, bronchitis and pneumonia. 2. Reproductive form: Erythematous and pustular lesions on vulvar and vaginal mucosa mucopurulent discharge from vulva and vagina. In bulls it will leads to pustular balanoposthitis and semen of such bulls will be infected. 3. Ocular form: Cause conjunctivitis, serous to purulent discharges, peticheal haemorrhages on conjunctiva and may leads to corneal opacity. Infection can lead to abortion at four months of gestation and in some cases autolysis of the foetus is also reported. 4. Encephalomyelitis: Rise in temperature, incoordination, tremor, circling falling, coma and death within four days of clinical signs. Lesions: Necrotic lesions on nostril and muzzle, pustular lesions on mucosa of vulva and vagina, foetal mummification, necrosis and autolysis are reported. Cowdry type A inclusion bodies are observed in epithelial cells. Diagnosis: Clinical findings and characteristic lesions, laboratory tests such as ELISA, CFT, FAT and SNT. Virus can be isolated from conjunctival swab, aborted materials, nasal swab, vaginal swab, semen, placenta, blood and serum. It should be differentially diagnosed from Pasturellosis, Para influenza, CBPP, and Verminous pneumonia. Treatment: Symptomatic. Broad spectrum antibiotic and fluid therapy can be done. Corticosteroids are contraindicated. Control: Isolation of the affected and treatment. Vaccines are available. a. IBRIVAX (Hoechst): Cattle &Buffalo- 2 mL IM/SC. Booster after 3 months and annual revaccination. Calf can be vaccinated at the age of 4-6 weeks.
