AARC Blog #8
Dr. Teresa Bousquet
Exotic Animal Veterinarian and AARC Board Member
Ranavirus is a virus that playing a major role in the decline of wild amphibians, and it’s impact has been compared to the devastation caused by chytridomycosis. Like Chytrid, Ranavirus has a world-wide distribution, having been identified in North America, South America, Europe, Asia, Australia and Africa.
Ranavirus can infect not only amphibians, but reptiles, and fish as well. More than 173 different species of affected animals have been identified so far, which broadens the economic and conservational concern of this disease.
Transmission can occur through exposure to contaminated water, contaminated soil, direct contact with an infected individual, or ingestion of infected tissue through predation, or cannibalism. “Stressors”, like pesticides and herbicides appear to increase susceptibility to Ranavirus infection.
Clinical signs can appear rapidly, and vary with the species affected. Mass die-offs can occur, particularly among juvenile and larval animals, and can affect more than 90% of animals in a given area. In amphibians, symptoms include lethargy, generalized reddening, fluid accumulation under the skin in lymphatic sacs, hemorrhage, swelling of the body and the limbs. Cases have been identified in wild Eastern Box Turtles, and in those cases, symptoms included weakness, swollen eyelids, discharge from the mouth and nose, and plaques in the mouth. Given that the virus cannot survive and replicate above 30C, it does not appear to pose a risk to humans, mammals and birds.
Prevention of spread would be similar to chytrid:
To reduce the risk of spreading Ranavirus from captive populations to wild populations, captive individuals must never be released into the wild. Water from captive tanks should never be poured into storm drains, which are not treated before flowing into lakes and rivers.
To avoid accidentally spreading Ranavirus between wild populations, boots, clothing and equipment must be thoroughly cleaned and disinfected between herping trips. Do not relocate amphibians between bodies of water. If you ever find evidence of a mass mortality event, please report it to your local Fish and Wildlife office, and the Alberta Volunteer Amphibian Monitoring Program.
For more information, please see the following websites:http://www.ranavirus.org/