If sanitary standards for cattle are not observed, animals of various kinds can be infected with infectious diseases. This, in turn, leads to a decrease in productivity, a loss of livestock, and, consequently, to a decrease in the profitability of farms. There are many diseases that affect cattle. In this case, one of the most dangerous is nodular dermatitis.
A bit of history
The disease is relatively new. Our ancestors did not know a similar problem with cattle. Nodular dermatitis was first recorded in 1929 in Madagascar and Northern Rhodesia. In 1945, cattle infection was recorded in Transvaal and Kenya. In 1963, cows were infected in Romania. Now this disease is especially common in India, as well as in South and East Africa.
Virus in Russia and in the territory of the former USSR
In our country, for the first time, animals infected with nodular dermatitis were detected on the territory of Chechnya in 2015, in the fall. More recently, in early June 2016, a disease such as cattle nodular dermatitis was discovered in the Krasnodar Territory (in the Tbilisi region). There is also information about previously infected animals in Dagestan, South Ossetia and Azerbaijan.
What causes
Cattle are infected with nodular dermatitis when DNA-containing Neethling, Allerton or BLD viruses enter the body of animals. They belong to the genus Capripoxvirus, the family Poxviridae. And most often the infection is caused by Neethling. This virus is reproduced in renal or testicular tissue. Its danger lies, among other things, in that it can withstand up to 3 freezing cycles. At a temperature of 4 degrees, it can remain viable for 6 months.
Sources of infection
Unfortunately, this disease can spread, including subject to sanitary standards for cattle in cowsheds. The fact is that mosquitoes and horseflies often become its carriers. Thus, infection can occur even when grazing cattle.
Actually, nodular cattle dermatitis (Neethling virus) enters the environment with pieces of animal skin falling from ulcers, with milk, saliva, sperm or blood. This disease gives additional difficulties to farmers also due to the lack of a visible pattern in distribution. That is, in some cases, the animal next to the infected does not become infected. In this case, a cow or a bull from a herd several kilometers away can get sick.
As can already be understood from the foregoing, the largest number of infected animals is observed in places of accumulation of blood-sucking insects. Sometimes nodular cattle dermatitis (virus) can also be carried by birds. In particular waterfowl. The dermatitis virus is also released with the respiration of infected animals. In some cases, it can be transmitted through feed and water.
Symptoms
The incubation period of the disease can last from 3 to 30 days. Since nodular dermatitis does not manifest itself in this period, animals are not isolated. Therefore, the risk of spreading the infection significantly increases.
The disease can manifest itself in two forms: acute and chronic. Atypical nodular dermatitis is also known. In acute form, a sick animal rises sharply body temperature (up to 40 degrees). At the same time, the appetite decreases in the cow or bull, tears flow and mucous discharge from the nose appears. After two days, nodules with a diameter of 0.5 to 7 cm and a height of up to 0.5 cm are formed on the skin of the animal. Their number can range from 10 to several hundred. In some cases, they merge.
The nodules are dense to the touch. After a few hours, the epidermis begins to exfoliate along their contour. At the same time, a hole is formed in the center of each nodule. With it, necrosis begins to spread. The affected areas are bordered by a roll of granulation tissue up to 3 mm wide. After a week, the necrotic area, which has the shape of a cylinder about 1 * 2 cm in size, dries and disappears. Subsequently, the cavity formed on the skin of the animal is filled with tissue and overgrows with pigment-free skin with hair. But this happens only in the absence of complications. It also happens that ulcers form on the skin of the animal. Some nodules may not dry out for a year or more.
In addition to skin lesions, nodular dermatitis in cattle (photos of sick animals can be seen on the page) are characterized by the following symptoms:
Pink color of milk. It gives up very hard - drop by drop. When heated, the milk of the infected animal takes on a gel-like appearance. It can be fed to calves after pasteurization at a temperature of 85 degrees for half an hour.
Emaciation of an animal due to loss of appetite.
The appearance of sores or erosion on the eyelids of a cow or bull.
Flowing saliva from the mouth and purulent fetid mucus from the nose.
Clouding of the cornea and decreased vision in the animal.
Sometimes ulceration appears in the respiratory tract of a cow or a bull. In this case, the animal may die from suffocation.
The atypical form of nodular dermatitis proceeds without the formation of nodules. It appears only in newborn calves.
How is the diagnosis
Infection is determined primarily on the basis of the overall clinical picture. In addition, laboratory diagnosis of a disease such as nodular cattle dermatitis is also carried out. San examination is carried out with the preliminary selection of biomaterial of suspicious animals. An established disease is considered when a virus of nodular dermatitis, its antigen or genome is detected. In especially severe cases, the diagnosis is made on the basis of pathological and anatomical studies.
Symptoms of nodular dermatitis are similar to manifestations of urticaria, dermatophilia, smallpox, demodecosis and lymphongitis. Sometimes this disease is confused even with banal insect bites. Therefore, when any nodules appear on the skin of animals, laboratory tests are mandatory.
Pathological and anatomical changes
At the autopsy of a dead animal that has undergone nodular dermatitis in cattle, the treatment methods of which have not yet been developed, the following changes can be detected:
enlarged, swollen, juicy lymph nodes in the section;
hemorrhages up to 1 cm in size under visceral pleura;
pulmonary edema;
congestive plethora on the nasal mucosa;
epidermal necrosis;
blood clots in the veins under the nodules;
hemorrhage in the intestinal mucosa.
What damage can the disease cause?
Nodular dermatitis in cattle, the treatment of which, unfortunately, is not carried out, can affect from 5 to 50% of the animals of the herd. Sometimes it happens that the disease affects 100% of cattle. The death rate due to infection is usually not more than 10%, and most often from 1 to 5%.
Although this disease does not "mow" the herd as a whole, they attribute it to one of the most dangerous. The fact is that with its distribution, the productivity of animals is significantly reduced. At the same time, farmers suffer significant losses in the sale of both milk and meat, as well as skins. Extremely negatively, this disease affects the reproduction of cattle. Infected bulls become temporarily sterile. In diseased cows, sexual cycle is violated. In pregnant animals, abortions occur and dead calves are born.
In Russia, this disease has not yet caused much damage to farmers, since not many cows have become ill. In India, where it is very widespread, losses due to it can amount to up to 50 million rupees annually.
Prevention
Unfortunately, as already mentioned, it is very difficult to prevent the epidemic of nodular dermatitis. This disease is transmitted simply instantly. The answer to the question of how to treat nodular dermatitis in cows does not exist. In addition, immunity after a transmitted infection is developed quite poorly. That is, an ill animal, if favorable circumstances arise, can become infected again.
It is very difficult to prevent livestock infection with dermatitis. However, farmers can still minimize the risk of illness. Immunization of cows is carried out using a strain of the Neethlin virus similar to sheeppox. The latter is grown in the tissues of the testes of the lambs. Only such a virus gives immunity from nodular dermatitis. An ordinary sheep’s has no similar effect.
In addition to vaccinations themselves, preventive measures include:
preventing the development of dampness and, as a result, the appearance of a large number of blood-sucking insects in cowsheds;
treating animals and stalls with repellents;
preventing animals of unknown origin from being imported into safe farms without appropriate documents;
on personal farms, providing veterinarians access to sheds for examining animals upon request.
Vaccination schedule
A strain of cattle is administered subcutaneously. The first vaccination of young animals is injected at the age of three months. Do this twice with an interval of 2 weeks. Next, the vaccine is administered with a periodicity of one year. In case of detection of the disease, all animals should be vaccinated without exception, regardless of when they were immunized before.
Nodular dermatitis in cows: danger to humans and other animals
To vaccinate against this disease relies only cattle. Fortunately, there have still been no cases of the transmission of this disease from them to MRS. Also, the virus of nodular dermatitis is completely harmless to humans.
How to prevent the spread
Nodular dermatitis in cattle, the treatment of which is impossible, tends to spread rapidly. Therefore, when detecting sick animals, contact with other cows and bulls, as well as maintenance personnel, should be completely excluded. In addition, measures must be taken to prevent the transport of particles of infected tissue from the territory of the economy. All vehicles leaving the territory must be pre-disinfected. Outerwear and shoes of maintenance personnel (using formaldehyde vapor) are subjected to the same procedure.
Identified sick animals, as well as cows and bulls that were in direct contact with them, are killed with a bloodless method. Corpses of cattle, as well as residues of feed and litter are destroyed. Three times disinfection should be carried out in the farm itself. Manure from the stall is overtaken and also disinfected.
In order to contain the epidemic, among other things, restrictions must be adopted:
Special centers for the fight against this disease have been created in regions unsuccessful for nodular dermatitis. Farmers and homeowners can call if they suspect infection. In the Krasnodar Territory, for example, specialists can be called by dialing 4-12-47 or 4-12-33.
Nodular dermatitis in cattle was discovered at the farm. How to treat?
The natural recovery of livestock with nodular dermatitis is 90%. The most susceptible to this disease are pedigree bulls and cows. Unfortunately, the treatment of nodular dermatitis, as already mentioned, has not been developed. In some cases, chemotherapy can be used to prevent complications due to second infections. Sometimes animals are given antibiotics for the same purpose.
What do they say about the disease?
Many farmers ask their colleagues and veterinarians a question: “Who cured nodular dermatitis in a cow?”. Reviews about this disease exist as very serious. Therefore, experienced farmers and veterinarians advise newcomers not to self-medicate cows, but to slaughter them. But sometimes you can find the opinion that with the disease to ease the course of the disease, you can use special steroids and vitamins, as well as the antibiotic "Thalidomide" (causing, by the way, malformations in the offspring).
In Russia, this disease is not too common, which means that for domestic farmers the issue, at least for the moment (2016), is irrelevant. And consequently, there are no opinions on possible alternative methods of healing. But, most likely, in case of further spread of the disease, advice on how to deal with livestock during infection will be the same - slaughter.
Thus, the problem is really serious - nodular dermatitis in cattle. "How to treat this disease?" - the answer to this question, unfortunately, does not exist. In case of infection, cattle are slaughtered. Of course, this can cause tremendous damage to households. Therefore, preventive measures and measures to prevent the spread of nodular dermatitis in case of an outbreak should be taken.