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The slogan about rabbits that was circulating in the Soviet Union, “rabbits are not only warm fur, but also 4 kg of dietary meat,” is still remembered. And before, rabbits really were a profitable occupation for summer residents who kept animals on land plots issued to them by the state, without knowing the hassle. Rabbits could be bred in almost any quantity without concern for protection from disease. The main thing is that the neighbors in the dacha cooperative do not write slander.
Paradise for rabbit breeders lasted until 1984, when an RNA-containing virus first appeared in China, causing an incurable disease in rabbits. Moreover, a disease from which it is difficult to protect yourself, since usually the course of the disease is lightning fast.
Due to the fact that the quarantine barrier to the virus was not put in time and the Chinese rabbit came to Italy, the virus began to spread from China all over the world, and the viral hemorrhagic disease of rabbits began its victorious march.
The problem of counteracting the disease was aggravated by the fact that rabbits were often outwardly absolutely healthy until the last minutes of their lives, when they suddenly began to scream, fell, made agonizing movements and died.
In fact, the rabbits had been sick with HBV for at least 2 days, during which they managed to infect neighboring healthy animals with the virus.
In addition, at first the owners did not suspect that the virus could persist even in skins, which at that time were often exchanged for animal feed. Since often the feed for rabbits and the skins of slaughtered animals were stored in the same room, the feed also turned out to be infected with the virus. This helped the virus conquer more and more new territories.
The virus entered the Soviet Union from two directions at once: from the west, from where they bought European rabbit meat, and to the Far East directly from China through customs points on the Amur.
Thus, in the former USSR there was no area free from hemorrhagic disease of rabbits.
Today, two viruses: VGBK, together with myxomatosis, are literally the scourge of rabbit breeders all over the world, except for Australia, which do not allow rabbits to be raised even to slaughter weight.
A rabbit of any age can get sick with HBV, but the disease is especially dangerous for rabbits aged 2-3 months, among which the mortality rate from HBK reaches 100%.
The HBV virus is quite stable in the external environment and can withstand relatively high temperatures. At 60 ° C, the virus dies only after 10 minutes, so it is impossible to “warm up” the rabbit in such a way as to kill the virus. The animal will die sooner. Although many less resistant viruses die already at a temperature of 42 °, which a living organism is able to withstand. The same “fever” in case of illness is the body’s struggle with the virus.
In skins from sick rabbits, the virus persists for up to 3 months.
Ways of infection with the HBV virus
With a good resistance of the virus of this disease in the external environment, it can be brought to your rabbits by simply visiting a rabbit breeder friend who decided to show off a new rabbit. The virus is perfectly transmitted through clothing, shoes or on car wheels. Not to mention the hands, which are almost impossible to disinfect properly.
The main sources of infection are feed, manure from sick animals, bedding, water and soil contaminated with secretions from sick rabbits. Down and skins are also sources of the virus.
But even if the farm is in the wilderness, there is no guarantee that the rabbits will be able to avoid contracting hemorrhagic disease. In addition to the sources already mentioned, the virus can be carried by blood-sucking insects, rodents and birds. Themselves remaining immune to the disease.
Symptoms of the disease VGBK
The incubation period for the virus ranges from several hours to 3 days. There are no four forms of VHD that are standard for other diseases. This disease has only 2 forms of the course of the disease: hyperacute and acute.
With hyperacute, the rabbit looks completely healthy. The animal has a normal temperature, normal behaviors and appetite. Until the moment when he falls to the ground in convulsions.
In the acute form, the animal can notice signs of depression, CNS disorders, sometimes before death, the rabbit appears blood from the mouth, anus and nose. Moreover, blood from the nose can be mixed with mucopurulent discharge. There may be only blood from the nose. Maybe nothing will show up at all.
Therefore, if the rabbit suddenly “for no apparent reason” took it and died, it is necessary to give the corpse of the animal for research to the laboratory.
Diagnosis of the disease
An accurate diagnosis is established on the basis of anamnesis and pathoanatomical studies. In a rabbit that died from VGBK, at autopsy, hemorrhages are observed in the internal organs. In addition, virological studies are also carried out.
The autopsy shows that the cause of death of the rabbit was pulmonary edema. But the virus begins to develop in the liver, leading to irreversible changes in it by the time the animal dies. In fact, the liver after the death of a rabbit resembles a rotten rag, which is easily torn at hand. The liver is yellow-brown in color and enlarged.
In the photo you can see changes in the liver and lungs.
The heart is enlarged, flabby. The kidneys are red-brown in color with petechial hemorrhages. The spleen is dark cherry, swollen, enlarged from 1,5 to 3 times. The GI tract is inflamed.
Laboratory studies are needed to separate VBHC from viral respiratory diseases, pasteurellosis, staphylococcosis, and poisoning.
The latter is especially true since some poisonous plants also lead to rapid death. And many plants are so poisonous that you may not notice a small piece of poison in the hay for a rabbit.
Prevention and treatment of VGBK
With an outbreak of VGBK, only quarantine measures are possible. No treatment is carried out, since there are no medications for the virus. In the event of an outbreak of the disease, all sick and suspicious rabbits are slaughtered and burned.
Another thing is that the owners, who have seen what is happening inside a sick animal, are unlikely to eat this meat.
The remaining healthy rabbits are vaccinated. In the absence of a vaccine, the entire livestock on the farm is slaughtered. The farm is considered safe only 15 days after the last death of the rabbit and after all sanitary procedures have been carried out, sick rabbits have been slaughtered and healthy ones have been vaccinated.
Types of vaccine and vaccination schedule against the disease
To create immunity against HBV in Our Country, 6 variants of vaccines are produced, at least two of which are bivalent: against myxomatosis and VGBK and against pasteurellosis and VGBK. Previously, with a less rich choice, there was a vaccination scheme in which the first time the vaccine was injected into rabbits at the age of 1,5 months. The next time the vaccine was pierced 3 months after the first vaccination. The third and all subsequent vaccinations were carried out every six months.
Today we need to focus on the instructions for the vaccine.
And sometimes it happens that animals get sick immediately after vaccination. The last case suggests that the rabbits were already sick, they just had time to vaccinate just in the incubation period of the disease.
Veterinary stations recommend vaccinating rabbits at 1,5 months, but it happens that the cubs begin to die as early as a month. To prevent such cases, you must strictly follow the vaccination schedule for rabbits. Cubs from vaccinated queens have passive immunity up to 2 months.
In the event of a “breakdown” of the vaccine by the virus, all sick and suspicious rabbits will have to be slaughtered, and the serum against VBHK will be administered to conditionally healthy animals. This is not a vaccine, it is a drug that stimulates the immune system and has a preventive effect up to 30 days. Not the fact that it will help, but it will not make it worse.
What and how to disinfect
At VGBK, after the destruction of sick animals, they carry out a complete disinfection of not only equipment and staff clothing, but also all farm equipment, including cages, drinkers and feeders. As well as the building itself.
Disinfection is carried out with conventional disinfectants from the most available: chlorine, phenol, formalin and others. Also, a blowtorch or a gas burner is often used to burn out microorganisms. But if you remember that it takes 60 minutes for a virus to die at 10°C, it is easy to guess that either the blowtorch will be ineffective, or everything but the metal parts will burn out by then.
Today, there are more effective disinfectants that will help deal with the virus. Methods of disinfection and preparation for vaccination against HBV can be viewed on the video.
Rabbit vaccination scheme, reliable protection against death
Bedding, manure and contaminated feed are burned.
On forums and websites, you can often find the questions “is it possible to leave a rabbit that has survived after an outbreak of VGBK” or “is it possible to treat VGBK with folk remedies”. People, of course, feel sorry for losing all the animals on their farm, but in both cases the answer is no. The surviving rabbit becomes a carrier of the infection. Newly purchased rabbits will very quickly become infected with the virus and die.
Results
If the farm has been visited by the virus of this disease, the best option would be to slaughter all the available livestock and thoroughly disinfect the inventory, sparing neither effort nor time.