Scientific Review: rabbit haemorrhagic disease virus
OIE World Animal Health report
Immune Cell Pathology RHD paper
Clinical Veterinary Advisor
Birds and Exotic Pets
2013, Pages 381-383
Rabbit hemorrhagic disease is a serious and extremely contagious viral disease of domesticated and wild rabbits. Morbidity and mortality rates are high in unvaccinated animals; on some farms, most or all of the rabbits may die.
The first known outbreak occurred in China in 1984, apparently spread by Angora rabbits that had been imported from Europe. Within 9 months, this disease had killed 14 million domesticated rabbits in China. By the late 1990s, outbreaks had been reported from forty countries, and rabbit hemorrhagic disease had become endemic in a number of areas throughout the world. Other regions, including the Americas, have experienced only small periodic outbreaks in domesticated rabbits.
The pathogen that causes rabbit hemorrhagic disease belongs to the calicivirus family which infect a wide variety of animals. The three major viral subtypes include: RHDV ("RHDV1" or "classical RHDV"), RHDVa, and RHDV2.
The clinical signs of the disease don't vary between subtypes but RHDV and RHDVa, which are closely related, have shorter incubation periods and higher mortality rates than RHDV2, as detailed in a 2016 report from Iowa State University.
Rabbits can contract the virus through contact with infected rabbits or with other animals or materials — such as food, water, bedding and vehicles — that have been in contact with infected animals.
According to the U.S. Department of Agriculture, a very low dose, possibly as little as a few viral particles, is enough to cause infection. The virus is highly stable, especially in organic materials, and can remain viable for months in varied temperatures and over distances, enabling it to be spread by biting insects.
Transmission of RHDV may occur through direct contact with an infected animal, since infected rabbits may shed viral particles in their secretions and excretions, or indirectly by means of fomites-contaminated food, bedding, water, clothing, cages and equipment -or vector-borne transmission by scavenging mammals, birds and insects.
Although RHD does not pose a threat to humans, other animals or the food supply, the World Organisation for Animal Health, an international group based in France that tracks and disseminates information about animal diseases, requires that cases be reported by member countries, which includes the U.S. and Canada.
ANIMAL EMERGENCY & REFERRAL CENTER
Dr. Andrew Bean, DVM MPH DABVP
Exotic Animal Companion Mammal Practice, MN
The Rabbit Show interview of Dr. Chris Hayhow