The disease nodular dermatitis in cattle is also known as infectious nodular dermatitis or tuberculosis. The name is associated with the appearance of characteristic tubercles on the skin of animals. The disease rarely leads to the death of livestock, but impairs the ability to reproduce, reduces productivity, spoils the leather raw materials. In India and Africa, dermatitis annually causes millions of economic losses. In Russia, outbreaks of the disease in cows are mainly recorded in the southern regions.
Viral origin of the disease
Infectious nodular dermatitis is provoked by viruses that are transmitted by blood-sucking insects - mosquitoes, gadflies, and some species of flies. In the subsequent spread of the infection occurs through the particles of the affected skin, as well as through sick or ill animals. The main pathogens are the Orpheling virus and the Allerton and Nitling viruses. These are representatives resistant to low temperatures. Such a virus is not afraid of freezing and re-thawing. But it collapses in the sunlight.
For the treatment of premises from the virus use: a 20% solution of chloroform and ethyl, 5% solution of lysol or 1% phenol, 3% alkaline solution. It is possible to protect animals from the development of the disease by means of a vaccine against sheep pox.
As a rule, only cattle suffer from dermatitis. The virus is most dangerous for young and pedigree cows. They become infected more often and carry the disease harder. For a host, an infected cow is not dangerous - the person is immune to the nodular dermatitis virus.
Skin diseases may have a different etiology.
Viral origin of skin disease in animals is rare. More often, such violations are provoked by fungi, parasites, mechanical damage or disruption of the internal organs. Veterinarians are much more accustomed to other types of skin lesions, such as poddermatitis. Unlike nodular dermatitis, this disease is not contagious.
It usually occurs near the hooves and is caused by Staphylococcus aureus. Pododermatitis is not dangerous for an animal, modern antiseptics and antibiotics do an excellent job with such infectious pathologies. However, he also requires timely intervention. If Pododermatitis becomes a purulent form, then surgical treatment will be needed, otherwise the threat of bacterial sepsis arises.
How to notice that the animal is infected
The first symptom of cattle nodular dermatitis infection is redness and a skin rash in the form of tubercles. It can be both single formations, and multiple rashes. They appear a few days after infection. These places are noticeably hotter than the rest, indicating inflammatory reactions.
Inflammation can affect the deeper layers, including the muscles. The formation of painful ulcers is accompanied by fever, the temperature of the young can rise to 41 degrees. If a dairy cow is sick, then the pinkish color of milk may become a sign of nodular dermatitis, which, when heated, also becomes gel-like. The animal temporarily decreases appetite.
Often the lymph nodes are inflamed, but this can be associated with a secondary infection - just as with poddermatitis, the disease is often complicated by pathogenic microflora. Over time, the diseased areas as a result of tissue necrosis begin to flake off, the ulcers dry out and heal, forming scars.
Severe forms of the disease
In the acute form, nodular (to say “modular” - wrong) dermatitis in cows proceeds with a sharp critical increase in temperature, refusal of feed and weight loss. At the same time, the nodules are multiple, they are randomly located almost throughout the body, and over time they merge into large lesions.
In addition to the skin, necrotic processes occur on the mucous membranes. They look like serous-purulent formations. Erosion is observed on the eyelids. In this case, the eyes of the cow grow turbid, the animal partially or completely blind. Discharge from the mouth and nose become viscous and acquire a characteristic heavy smell.
Very quickly, swelling and purulent inflammation can move to the lower respiratory tract. In this case, the cow dies from asphyxia. It should also be borne in mind that the vaccine is not a medicine, and an already vaccinated animal may die if it was infected before the vaccination and was in the incubation period.
How to make an accurate diagnosis
Without the advice of an experienced veterinarian, signs of cattle nodular dermatitis can be confused with symptoms of other skin diseases. You should know that, in contrast to the tubercle:
- there is no peeling of the skin at the urticaria;
- tuberculosis does not have such a high temperature and the lymph nodes do not increase so much;
- when poddermatit ulcers are located symmetrically, the nodules are soft, purulent;
- with insect bites, the formations burst at the apex (with dermatitis, at the edges).
You can confirm the diagnosis by laboratory tests. In the blood and other biomaterials, the virus is detected in a few days. A more accurate result is obtained by histological examination of the elements of the neoplasms. However, during this time, the infection has time to penetrate into all organs. It happens that an accurate diagnosis can only be made after the death of an animal during an autopsy analysis.
What to do if the diagnosis is made
Contagious nodular dermatitis is a relatively young disease, it has not been studied enough, and how to treat animals for it is still unknown.
To stop the spread of the detected virus in the herd can only immediate elimination of infected animals and careful disinfection and disinfection in their places of detention. If the cow in the farm is one, or the area is permanently unfavorable, the animal is isolated, and the dermatitis is treated symptomatically.
In nine cases out of ten, the cow will recover independently. It is only necessary to help her complete feed and good care. The treatment consists in the antiseptic treatment of the nodules. Sulfonamides and antibiotics will help to avoid reinfection in cows. In this case, all rules of the sanitary and quarantine regime are strictly observed.
To protect cattle against nodular dermatitis, a subcutaneous vaccine has been developed. Vaccination is carried out for calves aged two months. Further repeated injections are required, since immunity is maintained only for a year. The vaccine can cause a local inflammatory reaction that lasts for two days.
Unpleasant consequences of the disease
Nodular dermatitis of cattle is a long-term disease. Symptomatic treatment helps the cow to get rid of a patchwork of skin lesions, although this is preceded by a long, phased recovery. First, on the affected areas there is a loss of hair, cracks, ulceration. And only with time the skin is restored completely.
Nodular dermatitis may be accompanied by pneumonia, breathing problems and reproduction. Late treatment leads to infection with a secondary infection, which often affects the joints. Sick cows reduce milk yield, bulls remain sterile for some time. The skin of the cattle that suffered dermatitis, after treatment, becomes leaky in the affected areas. In addition, the recovered animal can become a virus carrier and be a source of infection for other individuals.
Official orders of the Veterinary Department
By its climatic conditions, Russia is a territory that is not too favorable for nodular dermatitis. However, in some southern regions, outbreaks of a new disease are already registered, and the variability of the virus makes it necessary to take special measures against its spread. Therefore, according to the instructions of the Veterinary Department, it is recommended:
- total animal picking;
- preventive vaccination of cattle against nodular dermatitis (a vaccine against sheep pox is used in a 5-fold vaccination dose);
- constant treatment of livestock repellents;
- periodic veterinary examinations;
- when a virus is detected - quarantine measures for 30 days;
- restrictions on the sale of meat, dairy and leather products;
- during the year - ban on the movement of livestock outside the quarantine restricted zone.
For the first time, nodular dermatitis was described in 1929 in Madagascar and has long been a disease characteristic of the African continent, Argentina and India. After 40 years, this virus was detected in Europe. In Russia, the first infection with nodular dermatitis was recorded in 2015. Veterinary services are concerned to prevent the spread of infection throughout the country. In this case, in addition to preventive and quarantine measures, the awareness of cattle owners is extremely important.
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