Malignant catarrhal fever

What to look for

There are 2 different forms of the disease.

Head and eye form:

  • Usually occurs in single animals
  • Sudden onset of fever, depression, lack of appetite
  • A big drop in milk production in lactating cows
  • Copious discharges from the nostrils, red nose and cloudy eyes
  • May develop ulcers in the mouth
  • Affected animals generally die within a few days

Gut form:

  • May affect individual animals or occur as an outbreak
  • Much milder changes to the nostrils, eyes and mouth seen
  • Animals rapidly develop profuse diarrhoea and die quickly

Cause

A virus normally found in sheep without causing clinical signs of disease.

Spread of the disease

Most sheep are infected with the virus which is secreted in their nasal secretions. It is not clear how cattle become infected but the disease rarely occurs in cattle that do not have contact with sheep. Some cattle appear to become infected without showing any clinical signs but it is believed that there is no transfer of MCF virus between cattle.

Animals likely to be affected

Malignant Catarrhal Fever is an unusual condition that is most often seen in yearling animals. Wild and domesticated deer are also susceptible.

Other diseases with similar signs

May resemble some forms of Bovine Virus Diarrhoea mucosal disease (caused by bovine pestivirus) or exotic diseases such as Foot and Mouth Disease.

Confirming the diagnosis

Any suspected case of MCF should be investigated by your vet to rule out the possibility of the Foot and Mouth Disease or other similar diseases that do not occur in this country.

Treatment

There is no treatment for MCF and so infected animals should be humanely killed.

Risk factors

Running sheep and cattle together. There is no vaccine for MCF and no specific preventive measures.

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