"All glory to God, only cows ... foot and mouth disease still has not been bred," Leo Tolstoy wrote to his wife, Sofia Andreevna, from Yasnaya Polyana in 1900. As we see, and then the animals suffered from this viral disease. And most often - cattle. The disease brings with it a reduction in milk yields and a loss in the weight of cows, a greater mortality rate among the young. The main economic damage associated with the need for quarantine measures, when you have to destroy millions of livestock. A person also sometimes gets infected, although it rarely happens. As a rule, children become ill after eating milk infected with foot and mouth disease.
Viral origin of the disease
Descriptions of foot and mouth disease are found already in the middle of the XVI century, in the works of the Venetian doctor and researcher D. Frakastoro. Currently, the virus is found in animals not only in Europe and Russia, but also in Asian countries, America, Africa. The last time in 2005 in the Far East among the cows was recorded a strong outbreak of foot-and-mouth disease, which crossed the Chinese border. Economic losses then exceeded 45 million rubles.
Due to the acute course and contagion of cattle foot and mouth disease, it was taken for a long time for the cattle plague. At the end of the XIX century, the culprit was discovered - a virus, a representative of the family Picornaviridae. It contains RNA (ribonucleic acid) in the protein coat.
In the first two days after FMD virus enters the body of the animal, its concentration occurs in the epithelium of aphthous blisters and in the lymph. In addition, it is contained in the physiological fluids: salivary and blood secretions, urine and feces. This extracellular agent has 7 types and a large number of varieties.
Far Eastern outbreak among cows was caused by Asia-1 type virus. Besides him, types A, O, and CAT-2 have a wide circulation in the world today. The ill animal receives immunity only to the type with which it was infected. Therefore, new infections of cows with other types of foot and mouth disease are not excluded.
Resistance to natural factors
In the external environment FMD virus persists for quite some time. On contaminated objects and animal dung - up to five months. For 40 days, the microbe maintains its activity even after rapid freezing of cow meat. Up to 50 days remains viable in milk after cooling. From 30 to 40 days he lives on wool and clothing.
However, in cow's milk at 37 degrees, the foot-and-mouth disease virus does not survive even 12 hours. In fermented milk products, it also quickly dies. Boiling kills his infection immediately, and the microorganism can withstand a temperature of 60 degrees for no more than 15 minutes.
How the virus enters the body
The microbe is transported by diseased animals and convalescents (virus carriers). A sick cow can still be dangerous for a long time, becoming the guardian and carrier of FMD virus. The most likely routes of infection are:
- contact with infected or ill animals;
- virus infected feeds;
- the use of milk from infected cows;
- pasture or place for watering;
- aerogenic transfer of particles of infected dust particles, feed, excreta.
The source of cow infection can be attendants who carry the virus on contaminated clothing and animal care items. Even transport used on farms can become a carrier. Non-diseased themselves, but mechanically carrying the virus, dogs, cats, poultry, also become the passive distributors of the infection. Such insects of FMD include various insects, including mites and flies.
How pest works
Penetrating with food or through the skin into the body of a cow, foot and mouth disease virus is fixed in the epithelial tissues of the animal. It also multiplies there, which leads to the inclusion of inflammatory reactions. After a day, microbes begin to spread through the blood throughout the body. The general condition is rapidly deteriorating, fever begins.
The infected organism of a cow responds by producing immunity, neutralizing the infection in organs and tissues. However, the skin is the most defenseless in this disease, because the least provided with blood, and, therefore, antibodies.
The process can affect the heart muscle and the musculature of the skeleton of a cow. The time to fight this pathogen is limited.
Only timely recognition of the disease and prompt treatment of FMD can save livestock from total annihilation.
How to determine the disease
The first signs of FMD are loss of appetite. The temperature rises to 40-41 degrees. Heartbeat is increasing. At this time, the disease can be seen in the form of several primary aft (bubbles) the size of a millet grain on the oral mucosa, nasal wings, in the cracks of the hoof, on the udder of the cow. Small bubbles merge into large ones the size of a walnut. When aphthae burst, the aphthae secrete the lymph and form painful erosions. It is difficult for an animal to chew food and chewing gum. A typical clicking and smacking sound and frothy saliva appears in the corners of the mouth.
Hoof rash leads to lameness, gait change. Most of the time sick cows prefer to lie down, refuse to stand up. Milk changes its texture, it becomes slimy, acquires a bitter taste.
Foot and mouth disease in small calves can pass without the formation of bubble rashes. The disease in this case is similar in symptoms to acute gastroenteritis. The development of pathology can be both benign and malignant. In the second case, the virus damages the cardiovascular system of the animal, and the disease manifests as shortness of breath, wheezing, and general weakness.
The expected improvement on the 8-12th day does not occur. The pulse of the cow increases to 120, the functional disorders of the nervous system take on extreme forms - paralysis, paresis. In 25-50 cases out of 100 comes cardiac arrest with a fatal outcome.
Erosion - the gateway for infections
During the formation of aft, animals require special care. The result of the treatment of foot and mouth disease largely depends on the quality of their content. The resulting erosion becomes a gateway for infection with a secondary infection. The development of dermatitis, endometritis, arthritis, bronchopneumonia and other diseases caused by streptococci and staphylococci is possible. Blockage of the nipple canals and mastitis on the udder is one of the forms of manifestation of foot and mouth disease in cows.
It is necessary to provide animals with a dry and clean hygroscopic litter, a sufficient amount of clean water, regular airing of the room. Feed must be soft. Cows give flour talker, grass, good silage. Rest is provided to animals. Aphthae are treated with solutions:
- acetic acid (2%);
- potassium permanganate (0.1%);
- furatsilina (0.5%).
In difficult cases, cows are shown pain relief so that the animal can receive feed. To do this, the affected areas are smeared with anesthesin, novocaine and copper sulfate in the ratio 1: 1: 2, which is prepared on the basis of vaseline and fish oil.
The hooves of the cow should be kept clean, smearing with tar mixed in half with fish oil. Iodine tincture or streptotsid with potassium permanganate will help in case of inflammation. With proper care after a week erosion delayed.
Fighting the virus from the inside
FMD virus is diverse, so special preparations for the treatment of animals are not released. Assistance is mainly aimed at combating symptoms. In addition to drugs, modern antibiotics (cephalosporin and its analogues) are used for the external treatment of ulcers, especially in cases of secondary infection. To support the heart of the cow - heart means.
As a general strengthening measures, intravenous glucose injections are given or a glass of honey is given. In some cases, the cow is fed with a talker through a tube. Crucial in the treatment of this disease belongs to the timely organization of vaccinations.
How to protect animals from the disease
In disadvantaged areas, vaccination against foot and mouth disease of cattle is carried out to prevent pathology. For this purpose, hyperimmune sera have been created. A vaccine against FMD based on the blood of convalescents (virus carriers) is also used. If the animal was vaccinated for the first time, by the end of the third week after vaccination it forms an immunity and retains it for a year. The stability of antibodies in the blood of vaccinated cattle lasts 6 months. Vaccination is one of the important factors of the FMD well-being of Russia. When a threat of infection of cows and to protect against complications, improves the conditions of animals and appointed diet food.
Measures to combat FMD depend on the geography of the outbreak, the epizootic picture, the traditions of farming and other features. There are four approaches to this question:
- the rejection of vaccination, the elimination of all infected and potentially infected animals (radical);
- immunization only around the outbreak and the destruction of animals in the outbreak of infection;
- conducting regular vaccinations to cows for prophylaxis in border areas, killing patients in the outbreak and vaccination around the outbreak of infection;
- elimination of infected stock in combination with intensive vaccination and quarantine arrangements.
The first method effectively destroys the FMDV virus in the zone of its primary detection. Developed countries can afford it, since the economic damage in such cases amounts to millions of dollars. The third, based on regular immunization, allows you to successfully maintain protection against a dangerous virus in Russia. The latter, a comprehensive method, aims to protect against foot and mouth disease, not only in the source of infection, but also throughout the epizootic chain. Therefore, it is recognized as the most effective and is used in disadvantaged and bordering areas.
In Russia, there is a program to combat FMD virus. The complex of measures includes monitoring of the situation, control over the movement of animals, over the production of livestock farms in combination with regular vaccination. In case of detection of FMD, the corresponding instruction comes into force. By order of the governor in the village or farm quarantine is established. Due to the high infectivity of the virus, sanitary and quarantine measures carried out by the veterinary service should be strictly observed.
Have you encountered the problem of foot and mouth disease? If you have a private farm, do you practice vaccinations in your compound?
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