Vaccinating foxes against Parvovirus recommended
The parvovirus reproduces in rapidly dividing cells, such as the intestinal epithelium. The resulting atrophy of the intestinal villi may at worst cause hemorrhagic gastroenteritis and bloody diarrhoea. An infected animal excretes the virus in its faeces. The virus is persistent and can remain infectious for long periods in faeces-contaminated environments. Indirect infection between animals and farms occurs easily, for example via contaminated footwear or equipment.
The parvovirus is known to impair reproduction e.g. in pigs. In addition, it has been suggested that parvovirus infections decrease reproductive efficiency among foxes.
Disease prevention and vaccines
The problems caused by the parvovirus are partly due to conditions: high animal density increases disease pressure. Proper production hygiene is difficult to maintain if the animal density is high. It is therefore crucial to take care of the animals' general well-being and good production hygiene, to avoid traffic between fur farms and to ensure proper disease protection on farms. The parvovirus weakens bodily defence mechanisms, exposing the animal to other causes of disease.
There is no specific treatment for animals with the disease. Animals can be protected against problems caused by the parvovirus, through vaccination. There is no fox-specific parvovirus vaccination. Instead, foxes are vaccinated with vaccines developed for mink, using the mink parvovirus strain as the vaccine antigen. There have been suspicions that this vaccine offers foxes insufficient protection, but no reliable data exists on this. The Finnish Fur Breeders' Association (STKL) is organising a field trial to investigate the effectiveness of mink and dog vaccines on foxes.
Sufficient herd immunity is the only way to protect animals. Under high disease pressure, the virus may infect vaccinated animals also, but in such cases it is likely that the disease is less severe than among unvaccinated animals. At the moment, fur farms only vaccinate breeders. The whelps are protected only as long as they have maternal antibodies. Whelps lose the protection received from their vaccinated vixens in around two months. To ensure sufficient protection at herd level, infected fur farms should vaccinate whelps at the age of roughly two months. If the vixens have not been vaccinated, vaccines should be administered to the whelps at the age of 5–6 weeks.
The Finnish Fur Breeders' Association (STKL)
Researcher, Veterinarian Heli Kallio,
Production Animal and Wildlife Health Research Unit, tel. +358 50 405 5776
Senior Researcher, Veterinarian Karoliina Alm-Packalén,
Veterinary Virology Research Unit, tel. +358 40 486 0052
Field veterinarian Anna-Maria Moisander,
Pohjois-Suomen Turkiseläinten Kasvattajat ry (PSTK), tel. +358 50 586 8177
Information about the vaccination field test:
Veterinarian Tomas Häggvik,
the Finnish Fur Breeders' Association, tel. +358 50 464 8834