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 maintained and spread within a herd by the existence of persistently infected (PI) animals. PIs are created when pregnant cows become infected with the virus in the first 125 days of gestation. The disease is then passed through the placenta to the foetus. Many foetuses will die and be reabsorbed, whilst others will be aborted or stillborn, but many will survive to full term.

These live born calves are likely to be born PIs, many of which will grow poorly whilst others will appear clinically normal. PIs are known as ‘super-shedders’, excreting the virus throughout their lifetime in bodily secretions, such as nasal discharge and faeces. The virus can then spread through the herd by contact with PIs or their secretions.

Non-pregnant cattle which encounter the BVD infection may suffer only a mild disease, but the immunosuppressive impacts caused by BVD mean these cattle are more 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.

Find information on the BVDFree England scheme here.

Costs of the disease 

The true cost of the disease to the national herd is quoted as being between £25m and £61m per year; however, costs to individual herds will vary depending on the number of infected animal