Content
Necrobacteriosis of cattle is a fairly common disease in all regions of the Russian Federation where livestock farming is carried out. The pathology causes serious economic damage to farms, since during the period of illness, livestock loses milk production and up to 40% of body weight. Farm animals and humans are susceptible to necrobacteriosis. The disease is recorded most often in breeding and fattening farms and is characterized by damage to the limbs. The main cause of this disease in cattle is violation of veterinary, sanitary and technological standards. It can occur in acute, chronic and subacute forms.
What is necrobacteriosis
Examination of the oral mucosa of cattle
Bovine necrobacteriosis has another name - bovine panaritium. The disease is infectious, characterized by purulent lesions and necrosis of areas in the hoof area, inter-hoof cleft, and corolla. Sometimes the udder, genitals, lungs and liver are affected. In young individuals, necrosis of the mucous membranes in the mouth is often observed.
In the absence of proper therapy and the animal’s weak immune system, the disease becomes more serious within a few weeks. Bacteria multiply quite quickly, penetrating internal organs and tissues, causing severe intoxication in the body of cattle.
Necrobacteriosis of cattle began to actively spread on farms in the early 70s after a large batch of breeding animals arrived in the territory of the former USSR. To this day, veterinary specialists are doing everything possible to prevent the disease from spreading so actively. It is believed that leg infections are the biggest threat to dairy farms, because only a healthy cow can produce high milk yields. This requires good, strong limbs to move actively. With pain in the legs, individuals eat less and move less, thus significantly reducing milk production.
The causative agent of necrobacteriosis in cattle
The causative agent of necrobacteriosis in cattle is a non-motile toxin-forming anaerobic microorganism. A comfortable habitat for it is the digestive tract of livestock. Upon contact with oxygen it dies instantly. In the affected tissues and organs, the bacterium forms long colonies; single microorganisms are less common.
The causative agent of necrobacteriosis in cattle
The pathogen is divided into 4 types, of which the most pathogenic are serotypes A and AB. In the process of life, they form toxic compounds that are involved in the development of the disease. The bacterium dies, losing its pathogenic effect:
- while boiling for 1 minute;
- under the influence of sunlight – 10 hours;
- under the influence of chlorine - half an hour;
- upon contact with formaldehyde, alcohol (70%) – 10 minutes;
- from caustic soda - after 15 minutes.
Also, the necrobacteriosis bacterium is sensitive to antiseptics such as Lysol, creolin, phenol, and drugs from the tetracycline group. The pathogen is able to remain viable for a long time (up to 2 months) in soil and manure. The bacterium lives in moisture for up to 2-3 weeks.
Sources and routes of infection
The causative agent of infection in cattle enters the environment with various excretions of individuals - feces, urine, milk, mucus from the genitals. Infection occurs through contact. Microorganisms enter the body of cattle through the wound surface on the skin or mucous membranes. The danger is caused by individuals with a pronounced clinical picture of the disease and animals that have recovered from the disease.
Typically, the disease is registered on a farm after the import of a batch of livestock from a dysfunctional farm, without observing a 30-day quarantine. Further, necrobacteriosis is periodic in nature with an exacerbation in the autumn-spring season, especially if feeding and living conditions worsen. In addition, the following factors have a great influence on the development of the disease:
- untimely manure removal;
- poor quality floor in the barn;
- no hoof trimming;
- high humidity;
- skin parasites and other insects;
- injuries, wounds;
- decreased body resistance;
- walking in wetlands;
- lack of veterinary and zootechnical measures on farms.
Throughout the body of cattle, the infection spreads through the bloodstream, so secondary areas of damage are formed in the tissues, and necrosis also develops in the heart, liver, lungs, and other organs. As soon as the disease passes into this form, the prognosis becomes increasingly unfavorable.
Symptoms of necrobacteriosis in cattle
Without an examination by a veterinarian, it is difficult to recognize the manifestations of the disease, because the symptoms of necrobacteriosis in the body of cattle are also characteristic of a number of other pathologies.
Damage to cattle limbs by necrobacteriosis
Common symptoms of infection include:
- lack of appetite;
- depressed state;
- low productivity;
- limited mobility;
- weight loss;
- foci of purulent lesions of the skin, mucous membranes, and limbs of cattle.
With necrobacteriosis of the limbs (photo), an individual cattle tucks its legs under itself and limps. Examination of the hooves shows swelling, redness, and purulent discharge. At the first stage of the disease, necrosis has clear boundaries, then the lesions expand, fistulas and ulcers form. When palpated, severe pain occurs.
The skin is most often affected in the neck, limbs above the hooves, and genitals. Manifests itself in the form of ulcerations and abscesses.
With the development of necrobacteriosis in cattle on the mucous membranes, the mouth, nose, tongue, gums, and larynx suffer. On examination, foci of necrosis and ulcers are visible. Infected individuals experience increased salivation.
Necrobacteriosis of the cattle udder is characterized by the appearance of signs of purulent mastitis.
With necrobacteriosis of cattle, necrotic formations appear in the stomach, lungs, and liver from the internal organs. This form of the disease is the most severe. The prognosis of the disease is unfavorable. The animal dies after a couple of weeks from exhaustion.
Necrobacteriosis occurs differently in mature cattle and young animals. In adult animals, the incubation period can last up to 5 days, and then the disease becomes chronic. In this case, the infection is difficult to treat. Sometimes bacteria begin to spread through the lymphatic system, resulting in gangrene or pneumonia.
The incubation period in young individuals lasts no more than 3 days, after which the pathology becomes acute. Young animals experience severe diarrhea, which leads to rapid dehydration. As a rule, the cause of death is blood poisoning or exhaustion.
Vaccination of cattle against necrobacteriosis
Diagnosis of necrobacteriosis in cattle
Diagnosis is carried out comprehensively, taking into account epizootological data, clinical manifestations, pathological changes, as well as using laboratory tests according to the instructions for bovine necrobacteriosis. The diagnosis can be considered accurate in several cases:
- If laboratory animals become infected, they develop necrotic lesions at the injection site, resulting in their death. A culture of the pathogen is detected in smears.
- When determining a culture from pathological material with subsequent infection of laboratory animals.
When conducting a differential analysis, it is important not to confuse the infection with diseases such as brucellosis, plague, pneumonia, tuberculosis, foot and mouth disease, aphthous stomatitis, purulent endometritis. These pathologies have similar clinical manifestations to necrobacteriosis. In addition, veterinarians should rule out laminitis, dermatitis, erosion, ulcers and hoof injuries, and arthritis.
After the animals recovered, the development of immunity to bovine necrobacteriosis was not detected. For immunization, a polyvalent vaccine against bovine necrobacteriosis is used.
All types of laboratory tests take place in several stages. Initially, scrapings are taken from infected tissues and mucous membranes. In addition, urine, saliva, and genital swabs are collected.
The next step will be the isolation and identification of the causative agent of necrobacteriosis. The final stage involves some research on laboratory animals.
Pathoanatomical changes in dead animals with necrobacteriosis of the limbs in cattle suggest purulent arthritis, accumulation of exudate in muscle spaces, tendovaginitis, abscesses of various sizes, phlegmonous formations, foci of necrosis in the thigh muscles. With necrobacteriosis of organs, abscesses containing a purulent mass and necrosis are found. Pneumonia of a purulent-necrotic nature, pleurisy, pericarditis, and peritonitis are noted.
Necrobacteriosis of the skin of cattle
Treatment of necrobacteriosis in cattle
Immediately after the diagnosis of necrobacteriosis, treatment should begin.First of all, the infected animal must be isolated in a separate room, and the affected areas must be chemically cleaned and dead tissue removed. Wash the wounds with a solution of hydrogen peroxide, furacillin or other means.
Since the bacterium creates a kind of barrier between the vessels and infected tissues, the penetration of drugs is very difficult. That is why antibiotics in the treatment of necrobacteriosis in cattle are prescribed in slightly higher dosages. The most effective drugs include:
- erythromycin;
- penicillin;
- ampicillin;
- chloramphenicol.
Antibacterial agents for topical use, for example, aerosol antibiotics, show a positive effect. They are used after chemical cleaning of hooves.
Group therapy based on regular foot baths is widely used. Containers are installed in places where the animal most often moves. The bath contains disinfectants.
The treatment regimen for necrobacteriosis in cattle is drawn up by a veterinary specialist, based on the research conducted. Then he can change therapeutic measures depending on changes in the condition of the sick livestock.
Since bovine necrobacteriosis is a contagious disease for humans, it is necessary to exclude the slightest possibility of infection. To do this, farm employees need to know and follow basic rules of personal hygiene, use special clothing and gloves while working on the farm. Skin wounds should be treated promptly with antiseptic agents.
Preventive actions
Treatment of cattle hooves
Treatment and prevention of necrobacteriosis in cattle should also include improving the health of the entire farm where the disease was discovered. It is necessary to introduce a quarantine regime on the farm. During this period, you cannot import or export any livestock. All changes in maintenance, care, and nutrition must be agreed with a veterinarian. Sick cows and those with suspected necrobacteriosis are isolated from healthy ones, a treatment regimen is prescribed, and the rest are vaccinated. All livestock must be driven through special corridors with disinfectant solutions in containers every 7-10 days.
To slaughter cattle, it is necessary to prepare special sanitary slaughterhouses and obtain permission from the veterinary service. Cow carcasses are burned, or they can be processed into flour. Milk can only be used after pasteurization. Quarantine is lifted several months after the last infected animal has been cured or slaughtered.
General preventive measures include the following:
- the herd must be completed with healthy individuals from prosperous farms;
- arriving cows undergo a month-long quarantine;
- before introducing new individuals into the herd, they must be driven through a corridor with a disinfectant solution;
- daily cleaning of the barn;
- disinfection of the premises once every 3 months;
- hoof treatment 2 times a year;
- timely vaccination;
- balanced diet;
- vitamin supplements and minerals;
- Regular inspection of animals for injuries.
Also, to prevent the development of necrobacteriosis, the keeping of animals should be normalized. The premises must be promptly cleared of manure and the flooring replaced to avoid injury.
Conclusion
Necrobacteriosis of cattle is a complex systemic disease of an infectious nature. The risk group primarily includes young cattle. In the initial stages of the disease, with a competent treatment regimen drawn up by a veterinarian, the prognosis is favorable. Necrobacteriosis is successfully avoided by farms that are actively involved in prevention.
