BVD - Bovine Viral Diarrhoea


Bovine viral diarrhoea (BVD) is considered widespread in the UK and is also found in North America and some central European countries. The disease is caused by a pestivirus which principally infects cattle but which also infects sheep and other ruminants.

How is the disease transmitted and spread?

The BVD virus is spread by the existence of persistently infected (PI) animals in a herd through nose-to-nose contact and the constant excreting of the virus.

The main disease occurs when pregnant cows are infected and the disease is passed to the foetus; the earlier in the pregnancy this takes place, the more severe the infection as the foetus has less immunity. The foetuses can die and be reabsorbed but many survive to term; of these some will present as damaged and grow poorly but many will appear normal. However, they will all be persistently infected with the virus which is widespread in their bodies.

Non-pregnant cattle which encounter the BVD infection may suffer only a mild disease but could be susceptible to other infections such as pneumonia.

What are the clinical signs?

Acute infection with the BVD virus is usually subclinical, causing mild or undetected disease. In dairy cows, it may result in a temporary drop in milk yield and/or scour. In calves dual infections with respiratory or intestinal viruses may produce more serious clinical problems.

In some cases acute infection can cause severe intestinal diseases and even mortality for adult animals; it can also result in reproductive losses.

Prevention & control of the disease

Control and prevention can only be achieved through adhering to strict biosecurity procedures, vaccination and long term control strategies.

There are national initatives working with numerous parties across the countries to try to eradicate the disease.

Costs fo the disease 

The true cost of the disease to the national herd is quoted as being in the millions per year - costs to individual herds will vary depending on the number of infected animals.

Setting up a BVDFree programme on farm is a four-step process - ADAM

A - Assess the level of biosecurity and disease risk on farm

D - Define the BVD status of your herd

A - Action plan for control of BVD on farm put in place

M - Monitor progress - annual status check