Additional rules to contain deadly rabbit disease

Chris McGann
Communications

Good biosecurity practices will reduce risks to your
 fuzzy friends and help control the spread of disease.  

January 6, 2020 UPDATE: Rabbit hemorrhagic disease (RHD) continues to spread in northwest Washington. Three dead rabbits kept at a property in Clallam County tested positive for the disease last week.  

Washington State Veterinarian Brian Joseph said he expects the areas affected by the disease to continue to expand because it can be spread easily by a wide variety of means including small rodents, birds and larger carnivores.  

WSDA has quarantined the property where the disease was identified. WSDA is not currently expanding the general quarantine area described in the article below. We will continue to monitor the situation. Rabbit owners are urged to continue to maintain high levels of biosecurity to protect their animals.  

Original Post: 

A deadly rabbit disease that struck in the San Juan Islands this summer, but appeared to be under control, reemerged much closer to the mainland this month raising new concerns about containing the disease before is spreads further into the state.

WSDA has added Whidbey Island to a rabbit quarantine area established this summer in the San Juan Islands to contain an outbreak of rabbit hemorrhagic disease (RHD), an extremely contagious viral disease with high infection and death rates in domestic and feral rabbits.

Although the disease could be devastating to rabbit populations, it is not a human health risk.

Tracking the outbreak

In July and August, WSDA confirmed positive diagnoses of RHD found in domestic and feral rabbits on Orcas Island and San Juan Island. A die off consistent with the disease was also reported on Lopez Island in the following weeks. The department issued an emergency rule in these areas in September, restricting the movement of rabbits, rabbit products, rabbit equipment and crates to prevent the spread of RHD.

WDSA expanded the quarantine to Whidbey Island after a dead feral rabbit found there tested positive for RHD on November 7. There have been two additional reports of dead feral rabbits, and there are reports of no rabbits in places they had been seen frequently, such as Ft Casey.  The department stopped movement of rabbits in or out of the area to contain the disease before it spreads further onto the mainland and becomes endemic in Washington.

Impact

Rabbit breeders, people who own rabbits as companion animals, 4-H participants, and those who raise rabbits for consumption face substantial losses if the spread of RHD goes unchecked. The state veterinarian will investigate and test all domestic rabbit mortalities and will test feral rabbits in new geographic regions where RHD has not been diagnosed.

The RHD virus is easily spread through numerous means, including direct contact with infected live or dead rabbits and/or contact with contaminated equipment, tools, hutches, and bedding.

Biosecurity is the best defense 

In the U.S., RHD is considered a foreign animal disease; only rare, sporadic, and isolated cases have previously been reported in the U.S. This year’s outbreak in the San Juan Islands appeared to have been contained and run its course since no new cases had been confirmed since August.

The Whidbey Island case reinforces the fact that the virus can survive in the environment for several months. Maintaining biosecurity measures is critical in our effort to stop the spread of this disease.

Essential steps include:

• Keep a closed rabbitry
• Exclude wild and feral rabbits and predators from rabbitry
• Wash hands between handling rabbits in different pens or cages
• Clean and disinfect equipment, tools, footwear, feed and water containers, cages, etc.
• Control flies and biting insects
• Remove brush, grass, weeds, trash, and debris from rabbitry
• Protect feed from contamination by flies, birds, rodents, etc.
• Do not feed grass or other forage that could be contaminated with the virus
• Do not use forage, branches, etc. for bedding
• House rabbits indoors if possible
• Do not share equipment with others who raise rabbits
• Remove and bury or dispose of dead rabbits promptly
• Submit carcasses for examination and sampling promptly
• Contact a veterinarian promptly if sick or dead rabbits are observed
• Do not transport rabbits into or out of RHD quarantine areas
• Quarantine new rabbits or those returning from shows for one month

Vaccines

Vaccines for RHD exist but are costly and, because RHD is considered a foreign animal disease, the vaccines are only available in the U.S. through private veterinarians who have USDA authorization.
Rabbit owners interested in vaccinating their rabbits should contact their veterinarian.

For more information about RHD, check out WSDA’s Animal Health webpage that include links to the quarantine, a fact sheet and articles about the disease. You can also contact a WSDA veterinarian by e-mail.

Hot weather tips for pets and livestock

Dr. Minden Buswell
WSDA Veterinarian

As the summer heat rises, it's important to help
 your livestock stay cool.

Hot weather can reduce animals’ feed intake, growth, production, reproduction, welfare, and overall health. Each year the livestock and poultry industries lose billions due to livestock heat stress.

Here are a few tips and links to help keep your livestock and pets healthy during the summer heat.

Livestock heat stress: recognition, response, and prevention

According to this Washington State University Extension fact sheet, "Livestock Heat Stress: Recognition, Response and Prevention," keeping animals cool with shade, water on the skin, airflow and cool drinking water is important, especially if they show signs of heat stress. These warning signs include:

• Crowding around water tanks or shade
• Lethargy
• Poor appetite
• Increased respiratory rate
• Elevated heart rate
• Immobility or aimless wandering
• Drooling or slobbering
• Non-responsiveness
• Seizures
• Death

If you observe signs of heat stress, it's time to take action. To help cool them down, you should

1. Provide shade immediately.
2. Soak the animal's body with lukewarm to cool water.
3. Increase airflow around the animal using fans if possible.
4. Provide cool drinking water.
5. Minimize handling, transportation, and stress.
6. Call veterinarian for consultation.

A word about water

It may seem obvious that water requirements for livestock rise with the temperature, but some folks may not be aware of just how much more water animals need when it gets hot. According to information from University of Nebraska and University of Iowa extensions, water consumption when the temperature reaches 90 F can be almost twice what it is at 70 F.
Here’s a link to a useful fact sheet put out by the Iowa 4H.


Heat index:

 "Be prepared, even if the risk is several index units away. Additional
 solar heat, lack of air movement and heavy fat cover all can lead
 to disastrous effects of heat stress." NDSU Heat Stress Guide 

Many factors come into play when it comes to assessing the level of stress heat puts on animals. Physical workload, body weight, confinement and even hide color can all contribute to heat stress. For example, dark-hided animals are more susceptible to heat stress than their light-hided counter parts. But,  just like it does for people, humidity can really increase the discomfort on a hot day. As this table illustrates, the “feels like” factor should be taken into consideration, too.

Heat stress in cattle

With all that’s at stake, it pays to adopt a three-step plan for hot weather.

1. Learn how to identify the animals most at risk of heat stress.
2. Develop an action plan.
3. Know when to intervene.

North Dakota State University lays out a sensible approach to the problem in their brochure, "Dealing with Heat Stress in Beef Cattle Operations."

Visit WSDA's Animal Health Program webpage for other resources.

Washington rabbit owners - be aware of deadly rabbit virus reported in British Columbia

Dr. Lyndon Badcoe 
Animal Health Program, 
Field veterinarian 

A deadly virus that infects both domestic and feral European rabbits has been detected in British Columbia, and is good reason for owners of rabbits or fair managers with rabbit shows to take extra precautions this year. It is not known how this new rabbit hemorrhagic disease (RHD) serotype virus 2 would affect native North American wild rabbits.

The Canadian Food Inspection Agency (CFIA) reported the detection of rabbit hemorrhagic disease (RHD) serotype virus 2, or RHDV2, on March 8. Rabbit deaths were reported on Vancouver Island, and there are tests in progress to determine if this disease has spread to the Canadian mainland. Officials in Canada are currently reviewing a vaccine for RHDV2, but there is no vaccine available in the U.S.

Here is an in-depth, current report on rabbit hemorrhagic disease from Iowa State University's Center for Food Security and Public Health.

Rabbit hemorrhagic disease, or RHD, is easily spread among rabbits, causes a high rate of infection and death, and the agent (calicivirus) is very stable in the environment. The first signs of the disease can take up to nine days following infection, but affected rabbits can also develop a fever and die within 12 to 36 hours.

European rabbits have been shown to be affected by RHD and are the type of rabbit most commonly used as show animals by 4H, FFA and other hobby groups. The rabbits that died in British Columbia were European rabbits that had gone feral. It is not known how the virus would affect native North American rabbits, which are typically cottontail and jack rabbits.

Protecting your rabbit 

Since there are no vaccines currently available in the U.S. for the virus, the best way to protect your rabbits is by practicing good biosecurity, including good sanitation and disinfection, and keeping new rabbits separated from your existing flock.

With fairs, shows and exhibitions coming up soon, there is always the concern that someone could bring an infected rabbit from an area where the disease has been reported.

Remember that a certificate of veterinary inspection must accompany all animals entering Washington State, including rabbits.

Rabbits can shed the virus in urine or feces for as long as four weeks after infection. It can be spread on contaminated food, bedding, fur and water, or by direct contact with infected animals or contaminated objects. Rabbits can become infected through oral, nasal, or conjunctival routes in the eyes.

While the disease does not affect humans, it can be spread through contaminated clothing or vehicles, or other animal handling equipment. Biting insects, birds, rodents, and wild animals can also spread the virus. The virus can survive for long periods of time in the environment and remain infectious to animals.

Signs of infection in rabbits include:

• Listlessness
• Lack of appetite
• Congested membranes around the eyes 
• Nervousness 
• Lack of coordination 
• Excitement or paddling 
• Difficulty breathing 
• Blood-stained, frothy nasal discharge upon death

If you notice any of the symptoms listed above, contact your veterinarian. Rabbit hemorrhagic disease must be reported to state or federal authorities immediately upon diagnosis or suspicion of the disease.

To report a diagnosis or an unexplained increase in deaths among rabbits, you can contact WSDA at 360-902-1878 or 1-800-606-3056. Wild rabbit die-offs can be reported at wildlife.health@dfw.wa.gov or by visiting www.wdfw.wa.gov/conservation/health to file a report online.

Rabbit hemorrhagic disease in the RHD form has occurred in the U.S. before, back in 2000 in Iowa and in 2001 in Michigan, New York and Utah. However, the outbreaks were restricted to small groups of affected rabbits. RHDV2 has never been reported in the U.S.