Health care of farm animals Introduction The first step in controlling a disease is its diagnosis. Once the disease is known control measures should be based on the knowledge of the nature of the causal agent, the way it is excreted from the animal body and the mode of transmission. Hence, the farm manager should observe his animals daily and any incidence of ill health should be promptly studied and necessary measures taken. Help of a veterinarian should be sought whenever there is problem.

How to control / reduce the infection ? As soon as an outbreak occurs Segregate sick animals. Stop all animals, animal products, vehicles and persons coming into and out of the farm. Call a veterinarian for advice, adopt containment vaccination. Avoid grazing in a common place. Ban all visitors to the farm. Provide foot dips containing disinfectants at the entry of the farm and gear up sanitation and hygiene.

Isolation Isolation means segregation of animals, which are known to be or suspected to be affected with a contagious disease from the apparently healthy ones. The isolation ward should never be at a higher level than that of the healthy shed. Attendants working on sick animals and equipment such as buckets, shovels etc. used for them should not be used for healthy stock. If this is not practicable, the sick animals should be attended to daily, after the healthy stock. After this, the equipment should be thoroughly disinfected before they are used on healthy stock next day; the attendant too should wash his hands and feet in antiseptic and discard the clothes in which he worked. The isolated animals should be brought back into the herd only when the outbreak ends and they are fully recovered.

Quarantine Quarantine is the segregation of apparently healthy animals (especially animals being brought into the herd for the first time), which have been exposed to the risk of infection from those animals, which are healthy and unexposed to the risk of infection. The idea is to give sufficient time for any contagious disease that the quarantine animals may be having, to become active and obvious. Hence, the quarantined period depends on the incubation period of a disease. But in practice a quarantine period of 30 days covers almost all diseases. For rabies, the quarantine period should be about six months. During the quarantine period, animals should be thoroughly screened for parasitic infestation by faecal examination and de-worming carried out on the 23rd/24th day, if need be. The animals should also be subjected to dipping or spraying on the 25th/26th day for removing ectoparasites if any.

Vaccination Vaccination is a practice of artificially building up in the animal body immunity against specific infectious diseases by injecting biological agents called vaccines. The term vaccine is used to denote an antigen (substance form organisms) consisting of a live, attenuated or dead bacterium, virus or fungus and used for the production of active immunity in animals. The term also includes substances like toxins, toxoids or any other metabolites etc. produced by microbes and used for vaccination.

Immunity When a vaccine for any particular disease is injected into the animal body, after an interval of 14-21 days, antibodies against the particular disease are produced, that cause active immunity against the disease. During this interval, before antibodies make their appearance, there is often increased susceptibility to the disease in question. The duration for which immunity is imparted varies from vaccine to vaccine. Against certain diseases a second booster dose is required after the first vaccination for achieving stronger immunity.

Ring vaccination Vaccination may be used prophylactically to confer participation to confer protection in anticipation of a disease; but it is never a substitute to good sanitation and hygiene on animal farms. A vaccine is not used as a rule in a locality, where an acute infection has already broken out, because of the period of increased susceptibility and the delay before protection is established. Vaccination is used to develop an immune zone all around an area of actual infection. This ring vaccination is done to all susceptible animals at a radius of 5 km from the focus of infection. This vaccination starts from the periphery and reaches the centre. This prevents the spread of disease. Also, vaccination can be used routinely on animal farms as an insurance against possible disease flare-ups.

Brucella vaccination One important point about vaccine for control of brucellosis in cattle and buffaloes need be mentioned here. Vaccine for brucellosis consists of live organisms. Hence it should only be used on farms where the prevalence of this disease has been established.

Where from vaccines produced? Services of the local veterinarian should be utilised for vaccination. Vaccines and immune sera can be obtained from the Indian Veterinary Research Institute, Izatnagar, Uttar Pradesh, M/s Indian Immunologicals, Hyderabad and Various Biological Products Laboratories in different States. Immune sera against certain bacterial and viral diseases are also available. Immune sera are prepared by repeated injections into suitable animals of increasing doses of live, attenuated or dead bacteria or virus which leads to the production of antibodies against the specific bacterial or viral disease. Serum of such animals containing antibodies is harvested and used to protect valuable animals in the face of an actual infection.