How to treat hemorrhagic disease of rabbits?

Viral hemorrhagic disease of rabbits is a relatively recently discovered disease. It was first identified in the northern regions of China in the mid-80s of the last century. The highest degree of contagiousness led to the fact that this disease spread literally within a decade to all countries of the world, excluding Australia.

How to treat hemorrhagic disease of rabbits?

The lightning-fast course of the disease and almost 100 percent mortality among infected rabbits made this disease a real scourge of rabbit breeders around the world, because of which they suffered and still suffer enormous financial losses.

Essence of pathology

VGBK or necrotizing hepatitis of rabbits occurs when an animal is affected by an RNA-containing Caliciviridae virus. The causative agent of the disease has the strongest virulence. In environmental conditions, it remains active for several years. Resistant to chloroform, polyoxyethylene alkyl ether and phenol. In a 0,1% formalin solution, it is inactivated within an hour.

Unlike other diseases, the HBK virus has a high resistance to high temperatures. So for its deactivation, heating at a temperature of 50 degrees for at least an hour is required. At low temperatures, the virulence of the HBV pathogen persists for more than five years.

Distribution routes and signs

An HBV epidemic on a farm can begin when rabbits are purchased that are in the incubation period of the development of the disease and are kept together with the main livestock without observing quarantine periods. When using non-disinfected vehicles for transporting animals, in which sick or infected animals, their slaughter products (meat, skins), contaminated feed, equipment were previously transported.

In addition to airborne infection of healthy animals from sick animals, the spread of the virus, due to its high resistance in the external environment, can occur through feed, water, soil, bedding, and excrement of infected rabbits. It is also transmitted sexually from virus carriers.

Infection of healthy animals is possible through equipment, hands, clothes and shoes of the attendants. Cases of transmission of the disease through the skins and fluff of diseased rabbits have been reliably recorded. It is possible to become infected with viruses through the bites of blood-sucking insects. If hemorrhagic disease has attacked, rabbits can be affected by another disease called myxomatosis. For people and animals not related to rabbits, the causative agent of the disease is not pathogenic.

A feature of the disease is that rabbits up to two months are more resistant to it, in contrast to adult animals, which the disease affects regardless of gender and season. First of all, this pathology is distributed among pregnant and lactating rabbits. As a result of the disease in pregnant rabbits, spontaneous abortion occurs.

How to treat hemorrhagic disease of rabbits?

This pathology also differs in that it has only an acute and super-acute form. The incubation period can be fleeting – lasting several hours and longer developing within 2-3 days, in rare cases – up to 5. With a super-acute form, all the symptoms of the disease appear in a few minutes. An outwardly healthy animal is struck by a convulsive syndrome and it dies.

In the acute form, the symptoms of the disease can appear up to one and a half days before the death of the animal. This is expressed in the depressed state of the animal, refusal to eat. A sick animal sits motionless in a secluded corner. In some animals, yellowish or bloody discharge from the nose is observed just before death.

A small percentage of affected animals can survive. They acquire lifelong immunity from VGBK. Although without visible signs, they remain virus carriers for several months and are able to infect other rabbits. Therefore, after an HBV epidemic on the farm, it is recommended to get rid of even surviving animals or keep them for a long time in a separate room and have separate equipment for them.

Diagnostic measures

In laboratory studies, it was found that half an hour after infection, blood coagulation occurs in rabbits inside the vessels. Then the body temperature rises above 40 degrees and after a few hours the animal dies.

Pathological anatomical studies show small hemorrhages in almost all internal organs. In this case, particularly destructive effects of the virus are observed in the liver, lungs, kidneys, heart, spleen and intestines. The liver becomes loose and acquires a brown color, on which lesions stand out with yellow spots. The heart and spleen significantly increase in size. In the last stage of the disease, the animal develops pulmonary edema and the animals die of suffocation.

Laboratory research methods make it possible to differentiate VGBK from myxomatosis, escherichiosis, pasteurellosis, salmonellosis, smallpox, eimeriosis and toxic liver damage.

Preventive measures

Since there are currently no cures for HBV, the only way to protect rabbits from this terrible disease is timely vaccination and compliance with veterinary and hygienic rules for rabbit breeding.

Both mono- and complex vaccines are used as preventive measures. The monovaccines against VHD include

  • tissue inactivated aluminum hydroxide vaccine;
  • tissue lyophilized vaccines: formol vaccine, teotropin vaccine and thermovaccine;

Comprehensive vaccines used to prevent two or more diseases include:

  • associated vaccine containing attenuated pathogens of myxomatosis and VGBK;
  • associated vaccine containing inactivated pathogens of pasteurellosis and VGBK.

The first vaccination against hemorrhagic disease should be given to rabbits at the age of one and a half months. 0,5 ml of the drug is administered intramuscularly, intradermally or subcutaneously. Immunity to the disease occurs on the third day after vaccination and persists for a year. If there is a risk of infection, re-vaccination is carried out every six months.

How to treat hemorrhagic disease of rabbits?

Pregnant rabbits can be vaccinated at any stage of pregnancy. Rabbits born from them have passive immunity to this type of infection for up to two months. In case of an acute threat of infection, an anti-HBV serum is used, which provides passive immunity for a month. Vaccination does not provide 60% protection to animals. However, even in the event of an epidemic, about XNUMX percent of the breeding stock survive.

Measures to combat the spread of VGBK

When the diagnosis is confirmed by laboratory tests, a quarantine is declared in the rabbit farm. At the same time, it is forbidden to import and export rabbits outside the farm. All sick or suspicious animals are slaughtered by a bloodless method, and the carcasses are burned.

In principle, slaughter products, skins and down from infected rabbits can be used. Their export outside the farm is prohibited in order to prevent the spread of the disease. The causative agent of infection on the skins remains viable for three months. If the skins are subjected to disinfection and aged for more than the specified period, they are suitable for sale.

To prevent the spread of the disease within the holding, it is prohibited to regroup animals and vaccinate against other diseases. You can not mow the grass in places where sick animals grazed, and take out infected manure to the fields.

Total disinfection is subjected not only to inventory and overalls of staff, but also to all farm equipment, including cages, drinkers and feeders. As well as the walls and floors of the building, walking yards and slaughterhouses. Quarantine is lifted two weeks after the last death.

The following measures will help reduce the risk of diseases among rabbits: fencing of the territory and entrances to the territory of the farm equipped with disinfectant barriers; change of clothes and footwear for service personnel; disinfectants at the entrance to the premises; the use of transport only within the farm and separately only for external trips, regular insecticidal treatment of the premises where the rabbits are kept.

How to treat hemorrhagic disease of rabbits?
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Anna Evans

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