Synonyms
Bovine herpes mammillitis virus
Introduction
Bovine herpesvirus-2 affects the teats and udders of cows as well as the perineum of cows in some cases and occasionally on the mouths and muzzles of suckling calves. It can also causes generalised disease in rare cases and lead to pseudolumpy skin disease. The disease is mostly seen in lactating cows. The virus is also zoonotic, causing lesions on the hands of milkers that touch the lesions.
Transmission is by entry into the skin through trauma, such as from rough milking or poor milk machine quality or other types of teat trauma.
Signalment
Usually dairy cattle in milk. It can also affect the muzzles of suckling calves.
Clinical Signs
Signs include the appearance of the lesions, which are generally moist, raised erosions or plaques found on the teat and udder. The cow may develop secondary bacterial mastitis and her milk production may drop.
Diagnosis
Characteristic lesions can lead to a presumptive diagnosis. Definitive diagnosis is by virus isolation from a sample of the lesion.
Treatment and Control
Control measures include ensuring the milking machine is in full working order with no faults e.g. check the pressure and clean or replace teat liners to prevent teat damage, which allows virus entry.
If treatment is neccesary, then there are topical antivirals avalibale where this is economically viable. There are no vaccines against this virus.
References
Andrews, A.H, Blowey, R.W, Boyd, H and Eddy, R.G. (2004) Bovine Medicine (Second edition), Blackwell Publishing
Merck & Co (2008) The Merck Veterinary Manual (Eighth Edition) Merial
Russell, P (2007) Virology Study Guide, Royal Veterinary College