Infectious Bovine Rhinotracheitis (Lecture)

Infectious Bovine Rhinotracheitis (Lecture)

1. INFECTIOUS BOVINE RHINOTRACHEITIS

2. Infectious Bovine Rhinotracheitis Highly contagious infectious viral disease of cattle and buffaloes that affects many systems. It affects younger and old cattle. In addition to causing respiratory disease, this virus can cause conjunctivitis, abortions, encephalitis, and generalized systemic infections.

3. Synonyms 1.Rednose 2.Infectious Pustular Vulvo Vaginitis 3.Infectious Balanoposthitis 4.Infectious Kerato Conjunctivitis 5. Coital vesicular exanthema, 6.Vesicular venereal disease 7.Vesicular vaginitis

4. INTRODUCTION BR is an acute, contagious respiratory disease of cattle caused by bovine herpesvirus type 1 (BHV-1), commonly affecting the respiratory tract and the reproductive system. It is highly contagious, resulting in rapid spread of respiratory disease among cattle in close confinement, particularly in feedlots and when groups of cattle are transported

5. Aetiology Agent—Herpesviridae –Bovine Herpes Virus -1. It has got different strains: 1.BHV 1.1-Respiratory 2.BHV 1.2-Genital 3.BHV 1.3-Encephalitic

6. SUSCPETIBLE HOST Cattle of all ages are affected. Besides, cattle, the disease have been traced in goat, swine and water buffalo. The disease has also been identified in wild ruminants. Wild animals remain as reservoir of infection.

7. TRANSMISSION Nasal exudate and Genital secretions Semen, foetal fluids and tissues Aerosol route Venereal transmission in genital diseases. IBRT virus survives up to one year in frozen semen. Tears, nasal discharge, coughed secretions, and all secretions and excretions of incubating and sick animals.

8. INCUBATION PERIOD 5-7 days normally.

9. PATHOGENESIS Virus enters through the respiratory tract, multiplies in nasal cavities and upper respiratory tract resulting in rhinitis, laryngitis and tracheitis. From the nasal cavities the infection spreads to the ocular tissues through lachrymal ducts and causes conjunctivitis. Virus also spreads through the trigeminal nerve to the brain resulting in non suppurative encephalitis. Localisation of the virus in various tissues results in systemic lesions. The virus is transported through the peripheral leucocytes to the placenta and foetus causing abortion. Foetus is highly susceptible to IBR virus.

10. CLINICAL SIGNS Young cattle are more susceptible Morbidity 100%, mortality–10% Fever , anorexia, mucus nasal discharge. Respiratory distress Mouth breathing, Dyspnoea, coughing Conjunctivitis . Ulcers in vagina and vulva, orchitis, abortion. Severe Rhinits and Running nose Tracheitis and Bellowing problems due to laryngeal infection.

11. 1.Respiratory Form: Rhinitis, Laryngitis, Tracheitis Red nose in calves, fever, nasal discharge which serous ,mucous and then turn to mucopurulent. Death due to asphyxia. Aspiration pneumonia, Dilated nostrils. Mouth breathing ,Lacrimation. Secondary bacterial infection by Pasteurella and Mannheimia. Latency due to settlement of virus in Trigeminal nerve.

12. Severe haemorrhagic tracheitis

13. 2.Neonatal/Encephalitic Form No respiratory involvement Brain-Non-suppurative encephalitis Ataxia Convulsion and Frothy mouth .

14. 3.Genital Form Called as Infectious Pustular Vulvo -Vaginitis, Infectious Balanoposthitis, , Coital vesicular exanthema, Vesicular venereal disease, Vesicular vaginitis. Petechia and erosion in vulva and vagina. Erosive ulcers in prepuce and penis. Spread through AI and by copulation.

15. 4.Abortion Form Abortion can happen at any stage but mostly during 3 rd trimester. Advanced Post-Mortem Autolysis of foetus. After death ,24-36hrs foetal expulsion occurs. Intranuclear inclusion bodies in foetal epithelial membrane.

16. DIAGNOSIS 1.Tentative:Clinical signs, History, etc. 2.Swabs from nasal mucosa, pharynx, tonsils etc. 3.Antibody: VNT , ELISA , 3. Antigen: PCR, FAT

17. PREVENTION AND CONTROL Quarantine the suspected. Treatment of diseased. Check the titre value of antibody. Proper Hygiene

18. FACTS 1.At a time, only one form is exhibited because of different strains producing different infection. 2.Latency due to settlement of virus in Sciatic and Trigeminal nerve. 3.Aspiration and Bronchopneumonia occurs due exudate aspiration and secondary bacterial infection respectively.

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