Vibriosis/campylobacteriosis
This is genital disease of cattle and sheep. The causal organism Campylobacter fetus is a gram negative, curved or spiral shaped bacteria having sometimes a longer form consisting of 4 or 5 coils. The organism is motile and needs low oxygen tension for growth. The saprophytic species can be differentiated from pathogenic ones on high tolerance of sodium chloride and glycerine for growth and certain biochemical tests. The organism is killed in 5 minutes at 580 C. It is easily destroyed by desiccation, direct sunlight and standard disinfectants. The organisms are usually present in faeces, soil and water.
Transmission: Transmission occurs by coitus. The organisms are found in the preputial cavity of infected bulls. Mature cows and heifers also carry the infection for long periods. Infected bull and semen from an infected bull are important source of spread of the disease. The organisms survive at low temperature used in semen storage.
Symptoms: Infertility caused may become apparent only when the %age of pregnancies in a dairy herd is low. The infertility rate in heifers is more than in cows. Abortions usually occur between fifth and sixth month of pregnancy. Infected bulls show no symptoms and their semen is normal. Healthy bulls become infected during coitus with diseased cows. Often the infection results in permanent infertility. Among sheep the disease is characterized by abortion occurring towards the end of gestation. Usually abortion is preceded by vaginal discharge for several days. The aborted foetus is oedematous with petechial haemorrhages on serous surfaces and necrotic foci in the liver.
Diagnosis: A history of sterility or abortion may provide evidence of infection. The final diagnosis depends upon the examination of uterine exudate and stomach contents of the aborted foetus. In both the cases, the causal organisms can be demonstrated microscopically or culturally. Serological tests, like agglutination test using serum or the vaginal mucus of diseased cattle for approximately 2-12 months after infection are conducted. ELISA and Complement Fixation Test (CFT) are also used for diagnosis. The infected bull can be detected by inseminating virgin heifers and examining the heifer’s vaginal mucus after 3-4 weeks.
Treatment: The bulls can be treated by injecting antibiotic cream in the prepuce. There is no direct treatment of females.
Control: Abortion rate can be reduced by antibiotic therapy, and particularly by using chlortetracycline and concurrently with the development of specific immunity. Irrigation of uterus and prepuce with streptomycin is often effective. The use of killed vaccines may reduce the incidence of disease in a herd but does not eradicate the infection. The immunity is of short duration.