Brucellosis in cattle: symptoms and transmission routes, treatment regimen and prevention

Brucellosis is a disease of infectious etiology of cattle, which is also dangerous for humans. In many animals, the consequences of the pathology are spontaneous abortions, defective discharge of the placenta, inability to reproduce, the birth of dead young or its early mortality. Brucellosis is a socially dangerous disease, which is why when it is detected on farms, a quarantine regime is mandatory.

What is bovine brucellosis

Brucellosis is an infectious disease transmitted from cattle to humans and manifested by multiple lesions of internal organs and systems. The pathology was discovered by the scientist D. Bruce in 1886, the pathogens were called brucella, and the disease itself was brucellosis.

The causative agent is a group of pathogenic microorganisms that are small and immobile. They do not form spores, but can form capsules. Brucella remain viable in favorable conditions (warm soil, manure, food) for up to several months. Under the influence of direct ultraviolet rays, they die after 1.5 days.

The danger of the disease lies in the high risk of human infection through the consumption of meat, milk and products prepared from it (cheese, cottage cheese, butter) obtained from cows with brucellosis. A person can become infected by contact with cattle secretions, for example, when fertilizing a summer cottage with manure from sick animals.

Transmission routes

The infectious disease is transmitted through injured skin, mucous tissues of the respiratory tract and gastrointestinal tract, as well as through skin punctures made by mice and blood-sucking insects.

A cow can get infected from an already sick animal. Often the pathogen is taken from infected amniotic fluid at the birth of a calf, spreads from a dead fetus during an abortion. The sources of the disease are the affected fluids - urine, semen, secretions from the genital tract, milk, and also feces.

Transmission factors are inventory, dishes, clothes of household workers, dirty hands, obstetric instruments that are not subjected to the necessary hygienic treatment.

How to recognize the disease

The incubation period of brucellosis lasts from one to three weeks, before a blood test does not detect antibodies to the pathogen. In most cases, the disease is asymptomatic and chronic. Often, farmers can only suspect a pathology after several abortions in adult cows that occur in the second half of gestation. Common complications of childbirth with brucellosis are retention of the placenta with further infection of the uterus, the development of mastitis, and a prolonged increase in temperature.

Sharp shape

Acute illness has the following symptoms:

raising the temperature to 38 ^oC;
excessive sweating;
lethargy, weakness;
enlarged lymph nodes;
eye damage;
inflammatory process of the heart, joints, bronchi and lungs.

There are severe pain in the ligaments, muscles, loss of appetite and weight loss.

Subacute animal

Signs of the subacute form are reduced to the appearance of inflammation of the joints (arthritis) in cows. Knee, carnal and other joints are painful and swollen. The subcutaneous tissue of the extremities, the mucous membrane of the vagina is affected, the udder becomes inflamed. Bursitis and abscesses may form on the hind legs. Sometimes the temperature rises to 37-37.5 ^{o, but decreases on its own.The subacute form of the disease can last up to three to six months.}

Chronic

In the chronic form of brucellosis, a cow is sick for six months or longer. Symptoms of the disease are erased. Pathology is manifested by subfebrile temperature, chronic inflammation of the joints, and spinal damage. Involvement in the process of the nervous system causes the development of neuritis and polyneuritis.

Diagnostic Methods

Since the signs inherent in brucellosis can also appear in other diseases, the main diagnostic method is to take blood to detect antibodies to the pathogen. In parallel, pathogenic microbes are looked for in milk, amniotic fluid. Pieces of tissue from a stillborn calf are examined. An allergy test is required.

The diagnosis of "brucellosis" is sometimes established post-mortem, when the pathogen is detected during a biopsy of the lymph nodes, joints, examination of the testes in bulls.

Disease treatment regimen

It is recommended to treat brucellosis with antibacterial agents, but this group of drugs is effective in the acute form of the disease. Antibiotics stop the process of reproduction of pathogenic microorganisms and contribute to the destruction of their colonies.

Antibacterial drugs are combined with each other, drugs are changed to avoid loss of sensitivity of the pathogen to the active substance. Combine two or three drugs from the following at once:

"Tetracycline";
"Doxycycline";
"Streptomycin";
Gentamicin;
Netilmicin.

The listed drugs have a better effect on the pathogen while using drugs that can penetrate the affected tissues - Biseptol, Ofloxacin, Ciprofloxacin and Fleroxacin (this medication is considered the most effective).

To relieve pain and reduce the level of inflammation, anti-inflammatory nonsteroidal agents are used - Brufen, Indomethacin. Reducing the intoxication of the body of cows is achieved by the appointment of "Methionine", "Adenosine triphosphate".

With the mass death of the pathogen in animals, a pronounced allergic reaction may occur, which is reduced by antihistamine preparations. At the stage of recovery, vitamins of group B and immunomodulators ("Dibazol", "Timalin") are necessarily introduced into therapy.

Vaccine and general prevention

Immediately after the detection of an infected animal, it is isolated from the general stall. To avoid further spread of the disease, disinfection is carried out with bleach or caustic soda (solution of 3% concentration). General prevention involves the prevention of infection of cows in prosperous farms and includes:

regular disinfection and disinfestation;
maintaining proper stocking;
observance of sanitary and hygienic standards when feeding, watering, keeping, mating animals;
carrying out routine serological examinations of cattle for brucellosis.

Animal caregivers are required to treat their hands with a 0.5% solution of chloramine or soda ash. Washstands with warm water, hygiene products and clean towels should be installed in the barn.

The most cost-effective means of preventing brucellosis is routine vaccination. Commonly recognized and effective vaccines against bovine disease:

Brucella abortus: CZV B-19 and RB-51 CZV;
Brucella melitensis CZV Rev-1 and

Vaccines provide strong and long-lasting immunity against brucellosis.

Is it possible to eat meat and drink the milk of sick people

When brucellosis is detected on the farm, it is declared unfavorable. Animals with a diagnosed pathology and with manifesting symptoms of brucellosis are sent for slaughter. It is forbidden to slaughter cattle on a farm where cattle are bred - for this, cows are sent to meat processing plants and sanitary slaughterhouses.

It is not recommended to eat the meat of sick animals, despite the fact that the causative agent of brucellosis quickly dies when boiled.

Milk and cream obtained from cows from a dysfunctional herd should be pasteurized at 70 ^oC for half an hour or boiled for 15-20 minutes. Milk taken from cows that react to brucellosis samples is used only in animal feeding, after boiling for half an hour.

To prevent the spread of brucellosis in a successful farm, it is important to carry out frequent hygienic processing of stalls. The causative agent of the disease is easily destroyed by a solution of carbolic acid at a 2% concentration, solutions of chloramine and bleach (0.2-1% concentration), solutions of creolin and lysol at a 3% concentration.

To prevent disease in humans, it is important to eat cow meat purchased at points with certificates confirming the absence of brucellosis in cattle. For prevention, milk from domestic cows is recommended to be pasteurized for 20-30 minutes.