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Leptospirosis in cattle is a fairly common disease of an infectious nature. Most often, the lack of proper care and feeding of cows leads to the mass death of animals from leptospirosis. The disease occurs with various lesions of the internal organs of cattle and poses the greatest danger to young and pregnant cows.
What is leptospirosis
Leptospirosis is a contagious disease of humans, wild and domestic animals, and has a bacterial character. For the first time this disease was noted in 1930 in the North Caucasus in cattle.
The causative agent of cattle leptospirosis is leptospira
The causative agent of leptospirosis in cattle is leptospira, pathogenic microorganisms. They have a curved body shape and are unusually active when moving. They live in a humid environment, for example, in the soil, they can remain viable for about a year. The bacteria get there with the faeces of infected cattle. Leptospira does not form a spore, quickly dies in the external environment. Exposure to direct sunlight is especially detrimental to her. Disinfectants also act on the bacteria.
Important! Leptospira die when water is heated to 60 ° C. When frozen in ice, they are able to remain active for a month.
Leptospirosis causes significant damage to the economy of many farms. In addition to the death of young cattle, leptospirosis provokes spontaneous abortions in adults, the birth of dead calves, the depletion of animals, and a significant decrease in milk production. The activity of leptospirosis is most often observed during the period of the beginning of grazing on pasture, in spring. Young animals suffer more from the disease, since they have not yet strengthened the immune system.
Sources of infection and routes of infection
One of the symptoms of leptospirosis is yellowness of the mucous membranes.
- aerogenic method;
- through open wounds on the skin, mucous membranes.
Outbreaks of infection occur during the warmer months. After the penetration of leptospira into the bloodstream of cattle, they begin active reproduction. The body of an infected individual, trying to get rid of the pathogen, releases toxins. They are the reason for the ailment. After infection of one animal, the infection is rapidly transmitted to the entire livestock with urine, saliva, and feces. Then the disease becomes epidemiological.
Forms of the course of the disease
Leptospirosis in cattle can take the following forms:
Each of these forms of the disease has its own characteristics of manifestation and treatment.
Symptoms of leptospirosis in cattle
Symptoms and treatment of leptospirosis in cattle largely depend on the course and form of the disease. For adults, an asymptomatic course of the disease is characteristic. Young animals suffer from the following manifestations:
- increased body temperature;
- the development of anemia and jaundice;
- atony of the proventriculus;
- muscle cramps;
- rapid pulse, shortness of breath;
- dark urine;
- loss of appetite;
- conjunctivitis, necrosis of the mucous membranes and skin.
The acute form of the disease causes death of the animal within 2 days after heart failure or kidney failure. In the chronic course of leptospirosis, the symptoms are not so pronounced, however, in the absence of therapy, they also lead to the death of cattle.
One of the first symptoms of leptospirosis in cattle that you need to pay attention to is a sharp hyperthermia, followed by a decrease in body temperature. In this case, the animal can show aggression.
A body of dirty water can be a source of contamination
The manifest form lasts up to 10 days. Typical signs of this form of the disease:
- increased body temperature up to 41.5 ° C;
- oppression of the animal;
- lack of gum;
- yellowness of the skin;
- painful urination;
- diarrhea, stool retention;
- soreness in the lumbar region on palpation;
- abortion of pregnant cows;
- tousled coat;
If treatment is not started on time, the mortality rate of livestock reaches 70%.
The chronic form of leptospirosis is characterized by exhaustion, a drop in milk yield and fat content, and the development of mastitis. The prognosis is most often favorable, as well as in the atypical form of the disease, which proceeds with erased clinical manifestations.
The subclinical course of leptospirosis in cattle is usually detected during routine diagnostics.
Attention! In pregnant individuals infected with leptospirosis, abortions occur 3-5 weeks after infection. Sometimes a miscarriage occurs in the second half of pregnancy.
Studies on leptospirosis in cattle
Diagnosis of cattle for leptospirosis involves the use of epizootological data, pathological observations, identification of symptoms and changes in the blood. During hematological examination in infected individuals, it is noted:
- low content of red blood cells;
- increased or decreased hemoglobin content;
- drop in blood sugar;
- increased bilirubin and plasma proteins.
Another of the clear signs of leptospirosis is the detection of antibodies to the pathogen in a fifth of the total cattle population. This will require a bacteriological analysis of cow urine. In addition, the diagnosis should be differentiated from listeriosis, chlamydia, piroplasmosis and brucellosis.
The final diagnosis is made after all the necessary studies (microscopy, histology, serological tests). Leptospirosis is established only after culture isolation. Thus, the diagnosis of leptospirosis in cattle should be comprehensive.
Treatment of leptospirosis in cattle
First of all, it is necessary to isolate diseased individuals from the herd in a separate room and create comfortable conditions for them. To combat leptospirosis in cattle, an injection of antileptospirotic serum is performed. Antibiotic therapy and symptomatic treatment of leptospirosis in cows will also be required.
Serum against bovine leptospirosis is injected subcutaneously at a dosage of 50-120 ml for adults and 20-60 ml for calves. The injection should be repeated after 2 days. Of the antibiotics, streptomycin, tetracycline or biomycin are used. The drugs are used for 4-5 days twice a day. To eliminate hypoglycemia, a glucose solution is administered intravenously. To normalize the function of the gastrointestinal tract, Glauber's salt is prescribed. Good results are obtained by taking caffeine and urotropine. If there are lesions of the oral mucosa, rinse with a manganese solution.
Attention! Leptospirosis is also dangerous for humans. Therefore, farm workers should take all necessary precautions.
The instructions for cattle leptospirosis provide for the examination of all animals in the herd if at least one sick individual is found. Further, all the livestock is divided into 2 halves: in one, animals with clinical signs of the disease, which are treated according to the scheme, as well as hopeless cows, subject to culling. Healthy cattle from the second half undergo compulsory immunization.
Pathological changes in leptospirosis in cattle
The corpse is emaciated, dry, the coat is dull with bald patches. When the carcass of an animal is opened, the following changes are observed:
- yellow tint of the skin, mucous membranes and internal organs;
- necrotic lesions and edema;
- accumulation of exudate mixed with pus and blood in the abdominal cavity and thoracic region.
Changes in the liver of an animal
Leptospirosis is especially strongly reflected in the cow's liver (photo). It is significantly increased in volume, the edges are somewhat rounded. In this case, the color of the organ is yellow, hemorrhages and foci of necrosis are visible under the membrane. The kidneys of the cow are also subject to changes. At autopsy, punctate hemorrhages and exudate are noticeable. The bladder is severely distended and full of urine. The gallbladder is filled with contents of a brown or dark green color.
Samples and analyzes taken from the organs of the corpse show changes as a result of the invasion.
Prevention of leptospirosis in cattle
Timely vaccination is one of the most effective measures to prevent disease in a livestock. For this, a multivalent vaccine against leptospirosis of cattle is used, which prevents the development of the disease in unfavorable farms. It includes various cultures of infectious agents that are inactivated by artificial means. The drug, entering the cow's body, leads to the development of stable immunity for a long time. After a certain time, re-vaccination will be required. The frequency of the procedure depends on the age of the animal.
In addition, the veterinary rules for leptospirosis of animals provide for the observance of sanitary and hygienic rules when breeding cattle on farms. Farm owners are required to:
- carry out regular inspection of individuals in the herd;
- feed with high-quality proven food and drink with clean water;
- change the litter in time;
- to fight rodents on the farm;
- carry out daily cleaning in the barn and disinfection once a month;
- graze livestock in areas with a clean water body;
- conduct routine diagnostics of the herd;
- to declare quarantine of cattle in case of suspicion of leptospirosis and when importing new animals.
It is also recommended that the fetus be tested for bacteria in a cow's miscarriage.
When quarantine is introduced on the farm, the movement of livestock within the territory and beyond is prohibited, individuals are not used for breeding work during this period, they do not sell products from the farm and grazing is prohibited. Disinfection and deratization of the barn and adjacent areas and premises should be carried out. Milk from infected cows is boiled and used only inside the farm. Milk from healthy individuals can be used without restriction. The quarantine is removed only after all the necessary measures and negative tests.
The vaccine is polyvalent
Warning! After quarantine for leptospirosis of cattle, the owner of the farm needs to revise the diet of the livestock, add vitamins and trace elements, and improve the conditions of detention.
Leptospirosis in cattle is a complex infectious disease in which all organs of the animal are affected. It is quite dangerous for humans, therefore, if a sick individual is found in a herd, it will be necessary to take all the necessary precautions to prevent further spread of infection in the herd and among staff on the farm. It is worth noting that with strict preventive measures, infection can be avoided.