Mycobacterium Bovis
CAUSE: Bovine tuberculosis (TB) is a highly infectious disease of cattle caused by the bacterium Mycobacterium bovis. It is a notifiable disease so any incidence of same on the farm has to be reported to the authorities and confirmed cases must be slaughtered. It is also a zoonose and so can be transmitted to humans via infected milk. It spreads throughout the herd via contaminated air, consumption of contaminated food and water, contact with infected animals through urine and faeces and contact with certain wildlife, such as the badger.
SYMPTOMS: TB is a progressive disease and symptoms can take months or years to manifest in the infected animal. These symptoms include weakness, loss of appetite, weight loss, fever and diarrhoea.
TREATMENT: There is no treatment available for bovine TB and so the ideal long term solution to the disease is eradication. A compulsory eradication programme introduced in Ireland in 1962 ensures that cattle are regularly tested for the disease to identify ‘reactors’ — animals that test positive for the disease. Such animals are slaughtered and restrictions are put in place in relation to the movement of animals onto or off the farm.
PREVENTION: Biosecurity on the farm serves to keep infectious diseases out of holdings and to reduce infectious disease threats on the farm. Adopting a closed herd policy ie no inward movement of cattle will eliminate the chances of TB and other infectious diseases entering the farm. Care should be taken when buying in cattle to ensure only recently tested animals are brought in contact with stock. Other measures such as footbaths, restriction of visitors, stock and disease-proof boundaries from neighbouring farms and disinfection of farming and veterinary equipment will all reduce the spread of infectious disease on the farm. Exercising caution in relation to wildlife will also help in the prevention of the disease. Checking fields for badger carcasses and being vigilant to unusual daytime sightings of the nocturnal animal will reduce the risk of spread of the disease if the badger is a possible cause.