Necrobacteriosis of cattle: pathogen and diagnosis. Description of the disease, symptoms, treatment

Necrobacteriosis of cattle is an infectious disease of animals caused by an anaerobic bacterium Fusobacterium necrophorum from the genus Fusarium. Its main unpleasant consequences are a significant decrease in milk yield and tribal losses. Although the mortality of livestock is rare in this disease, it can inflict enormous damage on farms. And therefore, it is important for farmers and owners of household plots to know how to properly carry out its prevention and treatment.

A bit of history

The causative agent of cattle necrobacteriosis is, thus, the bacterium Fusobacterium necrophorum. It was described already quite a long time ago - in 1882 by Leffler in the diphtheria of calves. He selected this stick from the cornea of a ram struck with smallpox, in 1881 R. Koch. Later, this virus was also detected by Schutz and Tartakovski. The pure culture of Fusobacterium necrophorum was first obtained by Bang in 1890. Regardless of it, in 1891 the microbiologist Schmorl did the same.

Necrobacteriosis of cattle: causative agent of the disease

The microbe Fusobacterium necrophorum is polymorphic and has the form of rods or of thin long filaments. The latter can form spherical or bulbous swellings. The bacterium Fusobacterium necrophorum is immobile, has no flagella and does not form spores or capsules. At the same time, it ferments glucose, levulose, galactose, sucrose, salicin and maltose. Ammonia does not produce this microbe. It does not restore nitrates to nitrates either.

The causative agent of Fusobacterium necrophorum is relatively unstable. But, unfortunately, it can persist for a long time in a variety of environmental objects. So, in feces of animals he lives up to 50 days, in urine and water - up to 15, and in milk - up to 35 days. The sun's rays on this microbe are destructive. Not in shadow, the bacterium dies after half a day.

The sensitivity of Fusobacterium necrophorum to various kinds of disinfectants is high. Therefore, observing the purity in barns, it is possible to significantly reduce the risk of development in animals of this disease. Kill the bacterium Fusobacterium necrophorum such antiseptics as:

• Sodium hydroxide and potassium (0.5%);
• Lysol (5%);
• Creole;
• Phenol (2%);
• Potassium permanganate (1: 1000).

Also this microbe is extremely sensitive to tetracycline drugs.

Symptoms of the disease

Necrobacteriosis of cattle shows itself mainly purulent lesions. They are manifested in cattle more often:

• On the udder;
• Lower limbs;
• The mucous membrane of the vagina and the uterus.

Necrobacteriosis of cattle is also characterized by diphtheritic inflammation of the mucous larynx, oral cavity and internal organs. Such symptoms are usually observed in young animals.

How does the infection occur?

Necro-bacteriosis develops in cattle often during trauma with damage to the skin. In the wounds, as a result of violation of the integrity of the capillaries, an oxygen-free environment favorable for the life of this anaerobic rod is formed. In particular, this virus multiplies in blood with hematomas. As a result of the vital activity of Fusobacterium necrophorum, a huge amount of toxic substances is formed. The latter block intracellular enzyme systems, which causes tissue necrosis. In this case, there is also an unfavorable process, such as blockage of capillaries with microbial cells.

There can be no infection only through wounds, but also through the mucous membranes of the digestive tract, in pathological births or in mating.

It spreads through the body this hematogenous way, that is, with blood flow. As a result, secondary lesions appear in the tissues. In addition, due to the penetration of the virus into the blood, septicemia develops and metastases of necrotic foci in the heart, liver and lungs are formed. If the disease passes into this stage, the treatment is usually inconclusive. When metastases are formed, the necrobacteriosis of cattle becomes malignant and the animal dies in most cases. Unfortunately, the cows who have undergone this disease, unfortunately, are practically not produced.

When can an animal be infected?

Infection with necrobacteriosis of cattle often occurs:

• Because of unsanitary conditions in the barn;
• Due to non-compliance with the prescribed frequency of preventive trimming of hooves;
• Due to the lack of equipment of the barn (in severely shortened stalls, in the absence of litter in animals);
• As a result of chronic rumen acidosis.

Sources of infection

The causative agent of necrobacteriosis is released into the environment with feces, saliva and urine of infected animals. Also this virus is contained in purulent discharge.

On the farm, the causative agent of necrobacteriosis most often falls with the acquired patient with repair young animals or producers. Some time after infection of the first animal, the infection in the barn becomes stationary. If the cattle treatment measures are not taken on time, the pathological processes become heavier because of the multiple transfer of bacteria from one individual to another.

The disease of nekrobakterioz cattle in the barn is uneven, manifesting itself in small epizootic outbreaks (sequential infection of animals).

Clinical picture

The incubation period of necrobacteriosis lasts several days. The symptoms of this contagious disease depend on many factors. For example, such as the age of the animal, the form of manifestation of necrobacteriosis and the features of its course. This disease can be both acute and chronic, as well as benign or malignant.

There are three main forms of necrobacteriosis:

• Limbs (ungulate);
• Mucous and skin;
• Internal organs.

The most common is ungulate nekrobakterioz cattle. A photo of the characteristic lesions that appear in this disease is presented below on the page. Most often in cattle with this form of the disease, hind legs (or one of them) suffer. Such a necrobacteriosis usually begins with the reddening of the intercostal fissure. At the next stage of the disease, bleeding purulent wounds, fistulas and abscesses appear. The animal experiences extremely unpleasant sensations and holds the affected limb by weight. During the examination, the swelling of the hoof phalanx joint is found. With further development of the disease, ligaments, bones and tendons are affected. If the process takes a malignant character, the overlying joints begin to ache in the animal - up to the hip.

The body temperature of the infected individual can rise to 42 g. Sometimes it also remains within normal limits. The necro-bacteriosis of the extremities is mainly caused only by adult cows and bulls. In calves this form is extremely rare.

With necrobacteriosis of mucous membranes and skin, lesions are most often observed in the trunk region, usually in the posterior part of the body. In young animals, purulent necrosis of the mucous membranes of the mouth, gums, trachea, tongue, nose, larynx, gastrointestinal tract, etc. can also be observed.

Necrobacteriosis of internal organs in cattle manifests itself most often as a liver abscess. In this case, typical clinical signs are usually not observed. But the animals themselves, infected with this form of necrobacteriosis, feel extremely unimportant - eat poorly, lose weight quickly, significantly reduce productivity, groan when trying to get up. With necrobacteriosis of internal organs, among other things, the cows can greatly increase body temperature.

Diagnostics

In addition to the symptomatic signs, the necrobacteriosis of cattle (the photo of the pathogen is presented below) can be determined by the results of laboratory tests. Such a check must be carried out necessarily. The fact is that the clinical picture of this disease can be similar to other common infections of cattle. It can be, for example, foot-and-mouth disease, vesicular stomatitis, viral diarrhea, plague or dermatophilia. Also, in the diagnosis of necrobacteriosis, arthritis of different etiology, erosion, hoof ulcer, dermatitis should be excluded.

How is it specifically determined such a disease as the necrobacteriosis of cattle? Diagnosis of it is usually performed according to a selected piece of tissue affected by necrosis, taken at the border with a healthy site. In the laboratory, this material is placed in a special medium (most often Kitt - Tarozzi with 10% blood serum) and incubated for two days at 37 ° C. To determine the concomitant microflora, additional studies are performed on the MPB and MPA. The final diagnosis of the animal is put in the event that a pathogen is found in the smears.

Necrobacteriosis of cattle: treatment with antibiotics

To take measures when there are signs of this disease should be immediately. Otherwise, pathological changes can become irreversible. Treatment of necrobacteriosis in the complex is under way. At the same time large farms use group methods, and in small farms they use individual methods. When treating dairy cows, only drugs that do not become milk are used.

At installation at КРС such diagnosis, as некробактериоз, carry out the following improving actions:

• Do a thorough chemical treatment of the affected areas with the removal of tissue.
• Wash rinsing with hydrogen peroxide, a solution of furacilin, etc.
• Apply liquid and powdered antiseptic drugs.

Anaerobic bacteria, including Fusobacterium necrophorum, always form a barrier between the vascular bed and the affected tissues. And this, in turn, greatly complicates the penetration of medicines. Therefore, antibiotics in the treatment of necrobacteriosis are used in elevated doses. In addition to tetracyclines, the most effective types of drugs from all used in this disease are:

• Levomycetin;
• Ampicillin;
• Erythromycin;
• penicillin;
• Telazine.

Also, for the treatment of a disease such as cattle necrobacteriosis in cows, modern antibacterial drugs of a wide range of action can be used. For topical application, aerosol antibiotics based on the above preparations are also suitable. They are used mainly for processing hooves after dry cleaning.

Restrictions on farms with outbreak of necrobacteriosis

When animals detect this disease on the farm, the following measures are taken:

• Infected animals are isolated from the herd;
• Hooves of healthy bulls and cows are treated in foot disinfectant baths;
• Treat the diseased animals according to the method described above.

If treatment, in view of the neglect of necrobacteriosis, is inappropriate, cows and bulls are handed over to a sanitary slaughterhouse.

What you need to know about

Unfortunately, necrobacteriosis of cattle is a contagious disease, including for people. Cases of infection of farm staff with this infection are rare, but not take into account the existing danger is not worth it. In order to exclude the possibility of infecting people working on the farm, with an outbreak of necrobacteriosis of cattle, it follows:

• Mandatory to observe the rules of personal hygiene when working with sick animals (wear overalls and gloves, after work take a shower);
• All the wounds on the skin need to be treated efficiently with effective antiseptic agents.

In the premises for the personnel of the farm there must be a first-aid kit, complete with all the necessary medicines.

Prophylaxis of necrobacteriosis

A number of pre-arranged activities helps to prevent the outbreak of a dangerous disease, such as necrobacteriosis of cattle. A vaccine for the prevention of this disease can be applied polyvalent, emulsified with VIEV or "Nekovak". In the farms located not far from the unfavorable for necrobacteriosis farms, among other things, the following measures should be taken:

• The farm personnel should carry out activities aimed at the overall strengthening of the animal organism. For this, balancing of animal feeding is performed first. In the diet of cows, bulls and calves, various vitamin and mineral supplements are mandatory. In addition, they carefully monitor the quality of feed.
• Perform activities aimed at improving the conditions of animals on the farm. Dung in the stalls must be cleaned carefully and on time. Also, if you suspect a possible infection with necrobacteriosis, all rooms should be inspected for signs of trauma.
• Purify and drain pastures and walking areas.

Among other things, should be periodically conducted on the farm with an outbreak of a disease such as necrobacteriosis of cattle, disinfection. In order to reduce the possible risks of loss of livestock to a minimum, it is also necessary to perform timely prevention and treatment of endometritis and mastitis. The fact is that these diseases can greatly complicate the course of necrobacteriosis.

How to deal with meat and milk

Necrobacteriosis of cattle causes significant damage to households primarily due to a decrease in the productivity of diseased animals. In the local pathological process, only the affected parts of the carcass of a cow or bull are sent for disposal. If the disease was septic, all slaughter products are burned. If the animal is afflicted with several internal organs, but its carcass thus has a sufficient degree of fatness, the decision on the possibility of using meat for food or for sale is taken after a thorough microbiological examination in the laboratory.

Skins of animals that have suffered from necrobacteriosis are dried in isolated rooms, disinfected according to instructions and implemented. Milk sick cows can be eaten only after pasteurization, carried out according to all the rules. From healthy animals, even from a dysfunctional farm, it is allowed to realize it freely.