Mucosal disease (bovine pestivirus or BVDV - bovine viral diarrhoea virus)
Causes:
Transmission is usually by direct contact with a carrier animal. The virus is common and if present in a herd many animals will be exposed and show antibody titres. The disease has its largest effect when it is introduced into a susceptible naïve herd in early pregnancy.
Clinical signs:
Wide range of signs depending on strain of virus and time of infection. Transient non-specific infection of cattle; however, if foetuses of naïve pregnant females are infected in-utero, immune incompetent calves can become persistently infected (PI) and will usually succumb to infection between six months and two years of age. Signs in affected young animals vary from mild diarrhoea to chronic ill-thrift and wastage in cattle up to 18 months to sudden death of cattle.
Clinical signs can also include temporary infertility, early embryonic death, neurological damage, weak, stunted or deformed calves
PI cattle spread the viral infection within and between herds.
Management strategy to prevent disease:
A vaccine is now available to control the disease.
Ensure replacement heifers develop a strong immunity before joining.
Strategies for managing mucosal disease (bovine pestivirus):
- Define pestivirus status in herd with serological testing of mobs.
- Identify and cull persistently infected cattle in conjunction with your veterinarian if outbreak has occurred. Note that removal of all persistently infected cattle may expose the herds to further outbreaks unless vaccination implemented
- Expose naive breeding cattle before mating to ensure they are immune when pregnant.
- Vaccination: Pestigard™ Vaccine (see more information on vaccination to prevent disease).