Malignant Catarrhal Fever Do Not Eat
Causative Agent
  • Malignant catarrhal fever (MCF) is an infectious, viral disease of many ruminants, including bison (Bison bison). It occurs worldwide and is generally sporadic, although herd outbreaks have been reported.
  • In North America, MCF is caused by ovine herpes virus-2, which infects sheep with no ill effects and spreads to susceptible species like bison.
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MCF Eye MCF Muzzle
Domestic cattle showing signs of MCF.
  • MCF has been documented worldwide in both wild and domestic ruminants.
  • MCF has not been detected in wild ruminants in BC.
  • MCF can occur any time throughout the year.
Hosts and Transmission
  • MCF has been documented in wild ruminants globally.
  • In Saskatchewan, MCF has been found to have been transferred from sheep to free-ranging moose (Alces alces).
  • Transmission of MCF had been shown to occur from animal to animal within the same species as well as from mother to young during pregnancy or birth.
Signs and Symptoms
  • Gross pathological changes are generally widespread and may involve most organ systems. The severity of this disease does vary, and signs include:
    • severe inflammation of the oral and nasal mucosa;
    • bleeding and inflammation of stomach and small intestine (hemorrhagic gastroenteritis);
    • fever;
    • diarrhea;
    • redness of oral and nasal mucosa with accompanying discharges;
    • encrustation of the muzzle and nasal area, causing obstruction of the nostrils and shortness of breath, open-mouthed breathing, and drooling;
    • skin lesions occasionally are seen, and horn as well as hooves wall may be loosened or sloughed;
    • clouding or ulceration of the eyes.
Meat Edible?
  • Not suitable for human consumption.
Human Health Concerns and Risk Reduction
  • The CFIA has recognized Bovine Malignant Catarrhal Fever as an annually notifiable disease, which in general are diseases that are present in Canada, but are not classified as reportable or immediately notifiable.
  • There is no zoonotic potential for this disease.
Samples for Diagnosis
  • A set of affected tissues should be collected in a 10% solution of formalin for microscopic examination.
  • Blood samples also can be submitted to diagnose this disease.
Further Reading
Return to Manual Home Page Disease List - Body Region Affected Disease List - Causative Agent or Risk Factor Disease Surveillance Form Glossary Contact Information
Return to Manual Home Page Return to Disease List - Body Region Affected Return to Disease List - Causative Agent or Risk Factor Disease Surveillance Form Download Glossary Contact Information