Viral hemorrhagic disease of rabbits (HBVC “hemorrhagic pneumonia” of rabbits, “necrotic hepatitis”) is an infectious, acute leaking highly contagious disease, which is characterized by a very rapid spread among the adult livestock of rabbits with symptoms of hemorrhagic diathesis in all organs and accompanied by high mortality (80-100%).
VGBK was first registered in 1984 in China, where it received the widest distribution. Later, through rabbit meat, which was imported from China and Eastern Europe to Italy, the disease spread to most regions of Italy, where at that time there were about 80 million rabbits, as a result of which about 600 dysfunctional points of this disease were detected in the country, and rabbit breeders “overnight” "Went bankrupt. Subsequently, the disease was recorded in other countries of Europe, America and Southeast Asia.
In Russia For the first time, a disease among rabbits appeared in 1986 in the Far East at the Far East state farm bordering with China, specialists did not diagnose the disease in a timely manner, killed rabbits at the Birobidzhan meat processing plant, and sent about 5,000 skins to the Voskresenskaya felt factory. From there, the disease began to spread throughout the Moscow region and other regions of Russia. By 1987, 31 regions of the country, including the Vladimir region, were affected by the disease.
Pathways of transmission of the pathogen.
Source diseases with HBV are sick and ill rabbits and humans. The main ways of infection in the disease is alimentary and respiratory. As a transmission factor, there may be feed, manure, litter, water and soil infected with secretions from rabbit patients with HBV; fluff and skins from sick animals; infected articles made from fur raw materials, received within 3 months from items that were not healthy due to illness.
The causative agent of HBVC is an RNA-containing virus with extremely high virulence. It retains its virulence when frozen for 5 years, is resistant to ether and chloroform. Under natural conditions, adult rabbits and young animals older than 3 months are more susceptible to the virus, regardless of breed and gender. At the same time, young rabbits are more resistant to this disease. For humans and other animals, the disease is not dangerous. Outbreaks are not related to the season, epizootics occur at any time.
The incubation (hidden) period of the disease is 2-3 days, but sometimes it lasts up to 5 days. At lightning fast and super acute The rabbit breeder does not see any disease, he comes to feed the rabbits, and discovers their corpses. Usually apparently healthy rabbits make several jerky movements of their legs and die.
At acute course 2-4 days after infection, the rabbit breeder detects depression in the sick rabbits, lack of appetite, and nervous phenomena. The disease lasts 1-2 days. Rabbits refuse to feed, become irritable, make jerky movements with their limbs, throw their heads back, squeaks and groans are heard. Before death, individual sick rabbits may have a nasal discharge (yellow or bloody).
The main pathological changes in HBV are observed in the liver, lungs, kidneys, spleen, heart and gastrointestinal tract. Pathological changes are characterized by point and banded hemorrhages in the internal organs. In the lungs, edema develops, which is the ultimate cause of death of rabbits. All dead rabbits are defeated. liver, it is increased in volume, yellow-brown, flabby consistency, easily tears at hand, hemorrhages are visible under the capsule. The highest concentration of the virus occurs in the liver, in it it multiplies actively, causing changes that are incompatible with life, leading to death of rabbits. A heart usually increased in volume, the walls of the ventricles are stretched, flabby consistency, under the endo- and epicardium are multiple point and spotted hemorrhages. In the myocardium. granular dystrophy. Spleen swollen, dark cherry color, increased by 1.5-3 times. Kidney red-brown in color, with small-pointed hemorrhages under the capsule, increased several times. Gastrointestinal tract–– note catarrhal inflammation.
The diagnosis of HBVC is made in a comprehensive manner, taking into account epizootological data (sudden mass death of adults who are not vaccinated against HBVR rabbits, with rabbit immunity, fulminant spread of the disease in the absence of clinical signs), clinical signs (nervous phenomena and fever with a longer course of the disease, bloody and yellow discharge from the nose) and pathomorphological data in a laboratory study.
To confirm the diagnosis VGBK regional and republican veterinary laboratories veterinarian should correctly select samples of pathological material: parenchymatous organs (preferably the liver), from dead rabbits no later than 2-3 hours from the time of death or fresh corpses of rabbits. Samples must be placed in a tightly closed container, which is treated with a 5% solution of chloramine, then it is placed in a vessel with ice, sealed and sent on purpose to the veterinary laboratory. In an accompanying veterinarian, he details the epizootic situation in the farm (village), the clinical signs and the results of the pathological dissection of rabbits.
When establishing a diagnosis of rabbit viral hemorrhagic disease, the Governor of the region imposes a quarantine on the settlement, which should be guided by the “Instructions for the Prevention and Elimination of Rabbit Viral Hemorrhagic Disease (HBVC)”, approved by the deputy. Head of the Main Directorate of Veterinary of the USSR State Agricultural Committee on January 14, 1998, January 27, 1998. No. 432-3.
Under the conditions of restrictions in a dysfunctional clause it is prohibited:
- import and export of rabbits, their slaughter products, skins, fluff, equipment and feed;
- rearrangement of rabbits;
- organization of exhibitions and other events related to the accumulation of rabbits;
- rabbit exchange among their owners;
- trade in rabbits, slaughter products, skins and down;
- Harvesting and feeding rabbits grass and hay from places where sick rabbits could be or their corpses were present;
- feeding rabbits without disinfection of plant waste from markets, as well as from the population, canteens, cafes, etc.
In a dysfunctional paragraph is carried out:
- with the help of the administration of the settlements, accurate household records of the entire rabbit population;
- a thorough clinical examination to identify sick rabbits;
- all sick and disease-suspicious rabbits are killed by the bloodless method and burned with subsequent disposal in the Beccari pit;
- passive immunization for therapeutic and prophylactic purposes to all rabbits without exception;
- vaccination of the remaining conditionally healthy livestock;
- in the absence of a vaccine, in order to prevent the spread of the disease, organized the slaughter of all rabbits in a disadvantaged point. Sick and young rabbits under 2 months of age are killed by the bloodless method and disposed of together with skins in a Beccari pit. Healthy adult rabbits are killed for meat directly in a dysfunctional point (farm) in compliance with veterinary and sanitary rules, ensuring that the spread of the disease is not controlled by the state inspector. The carcasses of rabbits killed for meat are boiled and sold in a dysfunctional point without restrictions. Heads, paws, internal organs, blood and other products of slaughter after their treatment with disinfectants are also disposed of in a Beccari pit;
- thorough mechanical cleaning and disinfection of walking yards, equipment, slaughterhouses, as well as premises where rabbits were kept;
- mass awareness campaign, incl. in the mass media to prevent the spread of VGBK;
- daily pest control in rabbit rooms;
- rabbit skins prepared in a dysfunctional point are stored in isolation, packed in a dense double disinfected tissue, and sent directly to the processing plant for disinfection and processing, in agreement with the leadership of the regional veterinary service, according to the veterinary certificate of form No. 3-vet.
For the prevention of HBV in Russia, the following vaccines are used:
- inactivated tissue hydroxide aluminum formol vaccine;
- three variants of tissue lyophilized vaccine: formol vaccine, theotropin vaccine and thermal vaccine;
- associated lyophilized vaccine against myxomatosis and HBV;
- associated inactivated vaccine against pasteurellosis and HBV.
Rabbits are vaccinated at any time during pregnancy!
The vaccine, administered to the rabbit at a dose of 0.5 ml intramuscularly, creates intense immunity in rabbits from 1.5 months already on the 3rd day after the vaccination and lasts at least 12 months.
Rabbits obtained from vaccinated rabbits, up to two months, have passive immunity to HBVC.
For passive immunization of rabbits, serum against HBV is administered, which provides a preventive effect for 30 days.