Animal Health - Treatment & Needs - Cattle

What has animal experimentation achieved so far?

In any agricultural system animals are kept at a higher density than would be normal for their wild ancestors. As a result, when a disease enters a herd or flock it is likely to be transmitted easily between animals. So there has been a great emphasis on preventive treatment in veterinary research for farm animals. There are a large number of diseases in cattle that can be effectively controlled by vaccines – including blackleg, tetanus, rotavirus, infectious bovine rhinotracheitis, respiratory syncytial virus, pasteurellosis, enteritis, leptospirosis, ringworm, parainfluenzavirus, coronavirus and salmonella. It is estimated that the vaccines developed to prevent just two common diseases of cattle – rinderpest and anthrax – have been responsible for saving the lives of more than 100 million cattle around the world.

Meanwhile, the common respiratory condition of young cattle called husk was the first disease in any species in which an effective vaccine was developed against a large multicellular organism, the lungworm Dictyocaulus viviparous. Worm parasites of the gastrointestinal system are another important cause of disease in cattle. Effective treatments have been developed against all the common parasitic species but research into new treatments continues because of the ever-present risk that these organisms will become resistant to the currently available treatments.

Vaccines developed to prevent just two common diseases of cattle have saved more than 100 million cattle worldwide [Edinburgh University].

What diseases are important now?

Infectious diseases of cattle cause only a fraction of the economic damage now than they did, say, 50 years ago. So much of the attention nowadays focuses on those ‘production’ diseases that are not necessarily life threatening but can have a long term debilitating effect on animal welfare and productivity. Many of these conditions are caused by a combination of genetic, environmental, husbandry and nutritional factors such as lameness and some forms of mastitis in dairy cows.

Some infectious conditions have proved particularly difficult to eliminate even when a suitable vaccine is available, such as bovine virus diarrhoea. Research continues into the peculiarities of the virus that have made the condition so unresponsive to normal control measures. Other research is focussed on newly emerging conditions in cattle like neosporosis, an increasingly important cause of abortion. Of course, efforts will also continue to find more effective ways of dealing with devastating exotic diseases like foot-and-mouth.

How can humans benefit from research on cattle?

Protecting consumers of beef and dairy products is the main reason for carrying out research into cattle diseases – studies into the origins of BSE and its links to human variant CJD are by far the largest element in the British veterinary research budget. But this is by no means the only zoonotic disease associated with cattle.

Several other organisms normally found in cattle can be a cause of serious food poisoning incidents, such as salmonellosis, listeriosis, E coli and campylobacter. Also a mysterious organism called Mycobacterium paratuberculosis, the cause of Johne’s disease in cattle, has been cited as a possible cause of the human condition Crohn’s disease.