Photo: Crezalyn Nerona Uratsu / Getty Images
The deaths began on February 15: seemingly healthy bunnies who wander back and forth on a regular basis, eat normally, defecate regularly, and then seizures begin. “Someone saw them jerking and screaming,” recalled Lorelei D’Avolio, LVM, a certified veterinary practice manager with a veterinary-technical specialty in exotic at the Center for Avian and Exotic Medicine in Manhattan. “We tried to do CPR, but these rabbits died within minutes. They would convulse, scream horribly and die. “
D’Avolio saw some of the rabbits leave; Others expired overnight, their delicate bodies offering no visible clues as to what killed them. “It was terrifying,” D’Avolio said to the Cut. These were the people’s pets, who were housed together only temporarily, and it wasn’t until the fourth or fifth death that staff identified a possible culprit: the Type 2 rabbit hemorrhagic disease virus, a very rare calicivirus that never it had been detected in New York City. “It wasn’t really on our radar,” said D’Avolio. “We knew what it was, but we didn’t think it could happen [here], because it had never happened before. “
The center stopped accepting new rabbit patients on February 19 and sent as many of its furry wards as possible home, quarantining the rest on site. “The last rabbit, that we know of, died on February 29,” said D’Avolio. “We didn’t get the actual positive diagnosis until March 4.” Of 16 rabbits directly exposed to the virus, 14 died, baffling D’Avolio and his colleagues, who were unaware of any RHDV2 outbreak in New York. And meanwhile, across the country, the New Mexico state veterinarian’s office began hearing about massive deaths in wild cottontail and hare populations. Soon after, sudden and unexplained deaths occurred in domestic bunnies. Testing of one of these rabbits confirmed this: RHDV2 had arrived in New Mexico.
“We still have no idea where it originated,” Ralph Zimmerman, a New Mexico state veterinarian, told Cut. “It’s covered in snow and moved like crazy,” spreading across the southwest. So far in 2020, the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service says it has confirmed RHDV2 at 146 domestic locations and wildlife sites in Arizona, California, Colorado, Nevada, New Mexico , Utah and Texas. Although the trajectory of the rabbit virus mysteriously mirrors that of our own pandemic, timelines are almost the only common ground shared by RHDV2 and the new coronavirus. RHDV2 is “much more infectious than COVID”, D’Avolio warns. “It is much more persistent, it is resistant to extreme temperatures, it can be transmitted in insects, in channels. It can spread in water, it can spread in shoes. “
“We refer to him as the ‘Ebola bunny’,” says Dr. Amanda Jones, a veterinarian based in Killeen, Texas. He says he saw his first death from RHDV2 in mid-to-late April, shortly after the state’s first Hockley County case emerged hundreds of miles away.
The first recorded outbreak of rabbit hemorrhagic disease, according to a report from the University of Iowa, occurred in China in 1984. This genotype may have traveled in imported Angora rabbits from Europe and ended up killing about 14 million domestic buns. The variation behind the current outbreak came to the United States recently, appearing in Ohio in 2018 and then in Washington state in the summer of 2019. It may have originated in France around 2010 and has since established itself in Australia and Canada.
RHDV2 only affects rabbits, hares, and pikas, destroying cells in the liver and causing hepatitis. It also creates lesions in other organs (the heart, lungs) that lead to internal bleeding, which in turn explains why some RHDV2-positive rabbits present with bloody fluid around the mouth and nose. Jones “emphasizes that” it is not related in any way, shape or form “to Ebola, but its effects on the body may seem comparable: RHDV2 causes inflammation throughout the system and often bleeding. It moves quickly and ruthlessly once it invades a colony. Incubation takes three to nine days, and the death rate ranges from 50 to 70 percent, according to the USDA. And it’s tremendously contagious: “We had a guy with 200 rabbits, and the he lost everyone between a Friday afternoon and a Sunday night, “Zimmerman said.” It just happened and killed everything. “
The first and only warning sign for RHDV2 infection often occurs after the virus has already spread. Some rabbits with RHDV2 may appear a little sleepy once they get sick; some may lose interest in food. A sick bunny may experience seizures akin to a seizure, his lips peeling from his teeth in a morbid, cleft squeal. Normally, however, the only symptom is sudden death, but even that is not a true sign. “Rabbits are notoriously fickle creatures and tend to … die without good reason,” Jones explains. “It is really difficult to distinguish between a rabbit that was sick [with RHDV2] and a rabbit that was sick with something else. “The only way to know for sure if your rabbit had it is to send its carcass to the USDA Foreign Animal Disease Diagnostic Laboratory in Plum Island, New York, for posthumous testing.
RHDV2 does not affect people, cats or dogs, but it clings to clothing, shoes and fur. A person or pet can easily pick it up and take it home, where the virus almost always seems to thrive. RHDV2 could happily live on surfaces for 3.5 months at room temperature and 225 days at 39 degrees Fahrenheit. It can survive both freezing and temperatures up to 122 degrees for at least an hour. Only a handful of disinfectants, including chlorine, can kill it. And it is powerful. “Any contact with a sick rabbit can cause indoor rabbits … to get sick,” he says. Anne Martin, Ph.D., executive director of the House Rabbit Society. That contact could be as indirect as a fly landing on the body of an infected wild rabbit before buzzing into your home and going through a table with its little feet of contagion. If her bunny then hits that table, Martin warns that “she could die that way.”
Potentially, but not definitely, RHDV2’s widely variable death rate introduces another layer of chaos into the equation. RHDV2 kills many of its rabbit hosts, but those that survive, Zimmerman noted, “can shed anywhere from 30 days to 105 days,” which could transmit the virus. To avoid “constantly keeping a source available for exposure in that herd,” explained Zimmerman, New Mexico, and some of its neighbors, instituted a depopulation policy: When a rabbit in a domestic nest contracts the virus, the state veterinarian’s office requires that all rabbits be slaughtered. Between March and June, New Mexico confirmed 492 domestic rabbit deaths from RHDV2, but when depopulation is taken into account, the plague has claimed around 1,100 bunnies so far.
Fortunately, there is a vaccine for RHDV2; Unfortunately, vets have to go through a tangle of red tape to get it. RHDV2 qualifies as a foreign animal disease. As such, the US does not have a licensed vaccine prepared, requiring veterinarians to import one of two formulas: Eravac from Spain or Filavac from France, both killed virus vaccines made from live rabbit livers, based on of “emergency need,” means once the virus has been confirmed in the state. But demonstrating “emergency need” to the USDA is a long and arduous process that involves the top of a mountain of paperwork. Jones said he began seeking approval in early and mid-April and only received his request on June 9.
His experience seems standard. Martin said his search for vaccines took 32 days. Zimmerman’s first order took five weeks to complete. D’Avolio says the Center for Avian and Exotic Medicine ordered 500 vaccines as soon as he received positive test results, only to have his request and an appeal rejected, allegedly because New York doesn’t have an “active” problem in his rabbits. domestic and wild. But given the speed at which RHDV2 swells, and how it intrinsically catches officials with flat feet, unable to send protection until after the infection is underway, a six-week wait to receive a vaccine feels like a large window to stop viral spread.
The USDA says a nationally licensed vaccine could be ready by year-end; Meanwhile, the country must rely on unlicensed European imports, leaving rabbit owners with few options other than surveillance.
For now, says Zimmerman, biosecurity measures should remain the top priority for rabbit owners, at least for those in the southwest: “Secure them, keep them home, keep people with rabbits away from their rabbits, make sure keep wild rabbits away from your domestic rabbits. ” That means window and door screens, strict handwashing, taking off shoes, and even outer clothing when re-entering a rabbit house, considering D’Avolio and Zimmerman still don’t know exactly how RHDV2 came to be. its doors, nor Jones.
“I’m going to be really honest with you. I think there are more cases than have been reported, “Jones said. “This is not only going to go away. This is a new problem that is here to stay. “
