Myxomatoma, a type of pox, is hands-down the single most destructive virus to rabbits. Species specific to rabbits, it's a highly infectious disease caused by the Myxoma virus. It grows best in rabbit skin which makes it easy to contract from blood-sucking insects.
In 1950, the Commonwealth Scientific and Industrial Research Organization (CSIRO) in Australia released the virus in attempt to control the wild rabbit population which had reached plague proportions. Later, a French physician brought it to France with the same intention – to control rabbit over-population. Myxomatosis then spread through Britain either by farmers who wanted to achieve similar result, and surely by accident in some cases.
The ‘California Strain’ of Myxomatosis
Myxomatosis isn’t as rampant in the United States as it is in the UK, but the virus is common along the Pacific Coast of California and Oregon. While there are several known strains of the virus, the California strain is unique and has a 99% mortality rate. Myxoma’s ability to mutate each year is notorious, and the brush rabbit of California and Oregon is a natural host to the devastating disease.
Highly Contagious Disease
The European rabbit (Oryctolagus) is extremely susceptible to the disease, whereas, the Cottontail (Sylvilagus) and the Jack rabbit (Lepus) are barely affected. The least affected rabbits act as carriers and can spread the Myxoma virus wherever they wander. Unfortunately the European rabbit is the pet and breeding species in America.
Rabbit breeders become highly concerned when an infected rabbit shows up at a rabbit show or in a breeding facility, and for good reason. The virus has wiped out large rabbit breeding and showing operations in a matter of weeks. It’s important to note that humans can’t contract Myxomatosis.
Transmission of Myxoma virus
The incubation period from transmission to symptoms is anywhere form 48 hours to a week. Myxomatosis is transmitted through mosquitoes, rabbit fleas, mites, lice, and ticks. Most commonly mosquitoes transmit the deadly pox to our domestic rabbits by biting (and sucking the blood) a brush rabbit or hare, and then proceeding to bite a domestic rabbit. There is some evidence that the disease can winter-over in fleas only to be passed on the following year.
Signs And Symptoms
- One of the first signs is swelling of the eyes, lips, nose, ears, and genitals. The swelling could impair the rabbit’s vision.
- A thick eye discharge
- Lethargy
- Fever
- Loss of appetite
- Respiratory distress/lung infection in later stages
- Possible hemorrhaging and seizures
- Infected rabbits usually die within 7-10 days.
Prevention
- Mosquito control is the best prevention. No standing water in the vicinity, bug zappers, etc.
- Rabbit bedding kept as dry as possible, as mosquitoes thrive in moist conditions.
- Other external parasite control (fleas, mites, etc)
- Domestic rabbits should be kept away from areas where wild rabbits could frequent.
- Isolate ill rabbits immediately from herd.
- If treating the infected animal - always feed, and treat ill animals last. Wash hands and clothes in hot water immediately following the handling of ill rabbits.
- Isolate those animals thought to be exposed to the virus. Treat them exactly as you would an animal that was deemed infected. After 14 days, if there are no signs or symptoms, the rabbit can be brought back to the rabbitry.
Treatment
Currently, there isn’t an effective treatment for Myxomatosis. Euthanasia is recommended for the infected rabbit, as this is the most humane choice given the heart-breaking effects of the disease. If a rabbit does recover from the virus (which is incredibly rare), it is immune to the disease thereafter.
In the UK, there is an approved vaccination called, ‘Nobiva Myxo’. The vaccine isn’t currently available in the United States. Unfortunately, even if it does become available, it’s not effective on the California strain.
Related Reading
Interested in more on rabbits? Check out Rabbit Reproduction.
Chris McLaughlin - Chris McLaughlin's gardening books include "The Complete Idiot's Guide to Heirloom Vegetables." Check out her complete profile.
