Prevention and treatment of Bovine brucellosis

Brucellosis (brucellosis), also known as infectious abortion, is a contact infectious disease caused by brucellosis (brucellosis).

I. pathogen

The pathogen of this disease is Brucella. This pathogen is a tiny, nearly spherical bacterium with a size of 1.5 microns and 0.5 microns, irregular shape, no spores, no capsule and negative Gram staining. The pathogen is not resistant to heat and can be killed in 30 minutes at 60 ℃, but it has strong resistance to dryness and can survive for more than 2 months in dry soil. It can survive in hair and skin for 3 to 4 months. The resistance of sunlight exposure and general disinfectants is not strong. This pathogen has a strong invasive ability, which can invade the body not only from the operating mucosa and skin, but also from the normal skin and mucous membrane.

II. Popular characteristics

The susceptibility of cattle to the disease increases with the maturity of sexual organs. Sick cattle are the main source of infection. Bacteria are excreted with the vaginal secretions of diseased cows and semen of diseased bulls, especially aborted fetuses, placentas and amniotic fluid, which are transmitted through the digestive tract, mainly due to the intake of contaminated feed and drinking water by susceptible cattle. In addition, it is infected through direct contact, such as contact with contaminated appliances, or direct contact with diseased cattle, skin or mucous membranes. The disease is often endemic. In newly diagnosed herds, abortion can occur in different parity; in frequent herds, abortion mostly occurs in the first pregnancy.

III. Clinical symptoms

Except for miscarriage, other symptoms of cows are often not obvious. Abortion often occurs in the 5th to 8th month after pregnancy, resulting in stillbirth or weak fetus. Placenta retention or endometritis may occur after abortion. Continue to discharge brown malodorous fluid in the vagina after abortion. The bull develops orchitis and loses the ability to mate. Some sick cattle develop arthritis, synovial bursitis, lymphadenitis or abscess.

IV. Autopsy examination of pathological changes

Autopsy showed that the placenta showed yellowish colloid infiltration, with bran-like flocs and thick juice on the surface. There are mucous flocs in the stomach of the fetus, pleural effusion, enlarged lymph nodes and spleen, and necrotic foci.

5. Diagnosis

According to the epidemic characteristics, clinical symptoms and pathological changes, it is not easy to make a diagnosis, and it can only be diagnosed through laboratory diagnosis.

VI. Prevention

We should persist in self-breeding, strengthen the hygienic management of feeding, do a good job of killing insects and rats, and quarantine regularly (at least once or twice a year). It is strictly forbidden to buy cattle in epidemic areas. When you have to buy cattle, you must observe them in isolation for more than 30 days, and use agglutination reaction and other methods to do quarantine twice to confirm your health before you can join the group. In the aspect of immune prevention, brucellosis vaccines include Brucella sheep No. 5 vaccine, Brucella pig No. 2 vaccine and Brucella 19 vaccine. Cattle that have been vaccinated will no longer be quarantined. After the occurrence of brucellosis, if the number of cattle is small, it is better to eliminate the whole herd; if the herd is very large, you can eliminate the cattle through quarantine, or strictly isolate the diseased cows, temporarily use them to breed healthy calves, and the rest of the cattle should be vaccinated regularly every year. Aborted fetuses, placentas, amniotic fluid and vaginal secretions should be buried deeply, and contaminated barns and utensils should be disinfected by 3% to 5%. At the same time, to do a good job of personal protection, such as wearing gloves, masks, work clothes are often disinfected and so on.

VII. Treatment

The general diseased cattle should be eliminated and have no therapeutic value. The more expensive breeding cattle can be treated under isolated conditions. For cows with miscarriage with endometritis, 0.1% potassium permanganate solution can be used to rinse the vagina and uterus, once in the morning and once in the evening. In addition, antibiotics (such as tetracycline, oxytetracycline, streptomycin, etc.) were used.