Veterinary Notes for the Farmer

New Zealand Journal of Agriculture, Volume 68, Issue 5, 15 May 1944, Page 369

Veterinary Notes for the Farmer

Common Misconceptions of Animal Diseases

IN THEIR contact with farmers veterinarians sometimes meet with beliefs or notions which, when examined in the light of facts definitely established by science, prove to be erroneous. Here are some of them:— 1. That hydatid cysts are commonly found in rabbits. The reason for this common misbelief is that although cysts are often found in rabbits they are not the same as the hydatid cysts found in other animals, such as sheep, cattle, or pigs. , The cysts found in rabbits and hares may ■ be the intermediate stage , of either of two large tapeworms (several feet in length) which occur in dogs, (a) Cysticercus pisiformis is the intermediate stage of Taenia pisiformis in the dog. These cysts are found in the abdominal cavity of the rabbit. Each contains a tapeworm head which develops into a tapeworm when eaten by a dog. (b) Multiceps serialis is the intermediate stage of the tapeworm Taenia serialis in the dog.' These cysts are found in the intermuscular tissue of rabbits. Each cyst contains many tapeworm heads which develop into tapeworms when eaten by a dog. Hydatid cysts are never found in rabbits and are the intermediate stage of a quite different tapeworm (Echinococus granulosis) also found in the dog. This important tapeworm is only about a quarter of an inch in length. Rabbits, therefore, play, no part in the spread of hydatid disease in man and animals. Tuberculosis 2. That if a cow has tuberculosis her calf is likely to have it. This is not the case, as heredity plays a very small part in the transmission of tuberculosis. It is only very rarely that a calf is born with tuberculosis. The disease is

definitely uncommon in calves up to one year and the incidence increases with age. A calf reared on a tuberculous cow may, however, contract the disease from the milk, but tuberculosis is essentially an acquired disease, not a hereditary one.

3. That kidney disease is common in horses. This statement has no more truth in it than the common belief that backache is usually a sign of kidney trouble in human beings. On being called to a case of colic veterinarians are often told that the horse is “having trouble with his water.” This is probably because a horse suffering from colic, of ten makes frequent attempts to pass urine. The term colic means “pain in the abdomen” and is nearly always a sigh of trouble in the intestines and not in the kidneys or bladder. . Colic is the cause of nearly half the general death-rate in horses. The cause is usually neglect of the proper methods of feeding and watering. Horses, like other animals, respond to good treatment, and many cases of colic could be avoided by attention to the quality of the feed and avoidance of irregularities of feeding and watering. Strong Antiseptics 4. That the stronger an antiseptic is the more effective it is. Much harm is often done in the treatment of wounds or injuries in animals'by the application of strong or unsuitable antiseptics. The animal body has a very effective defence against. infection and modern antiseptic treatment aims at assisting this natural defence as far as possible. Strong disinfectants may kill bacteria, but they also irritate the tissues, kill ‘ the cells that would normally deal with the invading bacteria and so retard healing. Many modern anti-

septics do not kill the bacteria, but bypreventing their multiplication enable the natural defence mechanism of the body to overcome them. .• ~lt is wise, therefore, never to use antiseptics above the strength recommended by the manufacturers, and never to use irritant or unsuitable applications. 5. That if a cow is feeding on ergotaffected pastures the milk is dangerous to human health. Although this idea has been widely circulated there is no truth in it. The toxic substances found in ergot are not excreted in the milk, even when animals are suffering badly from ergot poisoning. It should therefore be quite clear that the idea that the milk ,is likely to have widespread effects on the health of those drinking it has not been proved. Assisting Nature 6. That the recovery of an animal can always he attributed to the effects of the medicine administered. Veterinarians are sometimes amazed at the faith farmers place in drugs, which are often administered indiscriminately, regardless of the requirements of indi-

victual cases. They are also amazed at the amount of money farmers are prepared to spend on drugs. If the . animal recovers the last particular medicine administered is invariably credited with a cure. This is not a very scientific attitude to adopt, and results from failure to recognise that natural powers of recovery exist to a-greater or less extent in the majority of disease conditions., . It. is .obvious that there must first of all be an accurate diagnosis of the complaint before rational treatment can be provided. All medicine should as far as possible, and in the absence of expert veterinary opinion, be given with a view to assisting nature to overcome the disease. 7. That tuberculosis of the lungs in human beings, is commonly contracted from cows. Although the bovine type of tubercle bacillus is an important cause of some tuberculosis in human beings, tuberculosis of the lungs is not one of them. This erroneous belief is not uncommon, and the . cow is often wrongly blamed for the spread of all forms of human tuberculosis. As a matter of fact less than one half per cent, of tuberculosis of the lungs in human beings results from the bovine type of infection. . The form of the disease for which infected . cows can often rightly be blamed is. tuberculosis other than that of the lungs in children up to 16 years of age. This refers particularly to tuberculosis .in the glands of the neck and to a less extent of the bones and joints and of the abdominal cavity. Children are much more susceptible than adults and it is . a wise procedure where cows are not tested for tuberculosis to make the milk safe by boiling or suitably pasteurising.

—A. G. BRASH,

B.V.Sc.,

Veterinarian, Christchurch.