Thousands of wild and domestic rabbits across the southwestern United States died from anviral infection.
The California Department of Fisheries and Wildlife has recently reported new cases from Palm Springs, making California the sixth state since viral haemorrhagic disease virus type 2.
First identified in wild American rabbits in March, this virus kills these animals and their close relatives such as hares and pika that lives in the mountains.
Sometimes, after death, it is possible to find blood signs on these rodents near the nose and mouth.
This virus cannot infect humans. However, the experts they fear that threatened species are endangered is that a disease that mainly affects wild rabbit populations could have very serious effects on the food chain.
In mid-May, the virus had hit wild rabbits found in New Mexico and then in Texas, Arizona, Colorado, Nevada and California.
Some cases of this disease had been found in domestic rabbits in the United States as early as 2018, but now that the virus is in nature, it is spreading uncontrollably.
Robust and highly contagious, according to the National Wildlife Health Center, this virus can survive freezing temperatures and for almost four months in dry areas.
It would seem to spread among rabbits not only through contact with a sick rabbit, but also through contact with their skin, meat or even the insects with which they have contact.
It is not currently clear how the virus reached the wild rabbits of North America, but a veterinarian from the state of New Mexico told the New York Times that a possible cause was the import of domestic rabbits from Europe.
In 2010, in fact, the virus was identified in France and has since spread to Europe and later appeared in Australia.
The original strain of the virus type 1 was first identified in China in 1984. Probably, some infected subjects have unknowingly reached the States and from there then the specimens present in nature.
In addition to the numerous wild rabbits, 470 domestic rabbits in New Mexico alone died from this virus and over 600 were euthanized on sites that raise rabbits as pets or for slaughter.
European veterinarians readily offered the US a vaccine against this disease, but because the virus was rare in the United States, the vaccine is not yet widely available.
States that have seen rabbit deaths related to bleeding disease may coordinate with the United States Department of Agriculture to import the vaccine, as did the state of New Mexico in order to protect much of the 6.7 million domestic rabbits in the United States.
As for the free specimens in nature, the discussion becomes more complicated. At present, work is underway in Portugal on a safe way to deliver the vaccine to wild rabbits, without subjecting them to stresses that could cause their death.
In the USA, however, work is also being done to look for possible subjects immune to the virus.