Vladislav Hanyeyev, Doctor of Veterinary Science

Bovine herpesvirus type 1, the virus known as infectious bovine rhinotracheitis (IBR), is common on farms around the world. This disease causes significant economic losses due to violations of cows’ reproduction and respiratory disease in calves. Animals after infection become lifelong carriers of the virus IBR, but due stressors of various origins (calving, changing diet and welfare, regrouping, extreme weather conditions, etc.) the virus begins to multiply, causing disease.

Clinical signs and economic losses

Clinical signs of IBR very different. Key signs are as follows:

• fever (up to 41ºC);
• loss of appetite and weight gain;
• increased frequency of breathing;
• nasal discharge (clear or turbid);
• leakage from the eye;
• redness around the eyeball (where usually is white);
• abortion;
• pustular vulvovaginitis in cows;
• cow infertility and early embryonic mortality.

Preliminary diagnosis is often put on the basis of history, clinical signs or pathological-anatomical changes. However, the different farms and in different groups of animals, they can be different. Diagnosis is confirmed in the laboratory based on the results of serological tests or analysis of nasal swabs (preferably in the acute stage of the disease when leakage is transparent), eyes or genitals for the presence of the virus or its particles (polymerase chain reaction).

Economic losses from IRT are huge and expressed in a reduction in milk production and fertility of cows, and a slowdown in weight gain in youngstock. In the worst scenario, animals can die.

Read more information in the magazine «Milk and Farm» № 6 (13), December 2012