Bovine alphaherpesvirus 1 (BoHV-1) is a virus of the family Herpesviridae and the subfamily Alphaherpesvirinae, known to cause several diseases worldwide in cattle, including rhinotracheitis, vaginitis, balanoposthitis, abortion, conjunctivitis, and enteritis.

It is spread horizontally through sexual contact, artificial insemination, and aerosol transmission and it may also be transmitted vertically across the placenta.

Although these symptoms are mainly non-life-threatening it is an economically important disease as infection may cause a drop in production and affect trade restrictions.

Aerosols have to be exhaled, sneezed, or coughed from an infected animal during viral shedding in order for transmission to occur.

[4] Infected animals will be continuous shedders throughout their lifetime when the virus reactivates; therefore, successfully propagating the disease.

Aside from cattle, studies experimentally infecting animals have shown that goats and buffalo can act as reservoirs for BoHV-1, as well as red deer, sheep, swine, and reindeer.

[2] Shedding begins from the nasal mucosa as soon as infection occurs, and the virus has replicated in the upper respiratory tract.

[2] Clinical symptoms include fever, serous to mucopurulent nasal discharge, coughing, sneezing, difficulty breathing, conjunctivitis and loss of appetite.

Serology may be performed to identify latent carriers, but it is not completely reliable as not all of the infected animals have detectable antibodies.

Vaccination is widely used both to protect cattle clinically in the case of infection and significantly reduce the shedding of the virus.

[8] Using a killed gE deleted marker vaccine after infection will reduce viral excretion following reactivation, using a dexamethasone treatment.

Countries such as Austria, Denmark, Finland, Sweden, Italy, Switzerland and Norway have eradicated the disease, while Canada and the United States have control programs in place for it.

Eradication was accomplished in Switzerland in 5 years using a four-step protocol focusing on preventions on transmission with trade barriers, slaughtering animals with antibodies to BHV-1, detection and eradication of further reservoirs (feedlot cattle), and then putting in place a monitoring program to maintain the control.

BoHV-1 is a source of economic loss in both the dairy, and the beef industries in Canada due to a decrease in production, a higher susceptibility to secondary infections, and the occurrences of abortions.