Veterinary Notes for the Farmer

New Zealand Journal of Agriculture, Volume 66, Issue 2, 15 February 1943, Page 97

Veterinary Notes for the Farmer

The Clinical Symptoms of Tuberculosis in Cattle

IT is important to be able to recognise a cow suffering from tuberculosis. First, a cow showing clinical symptoms usually has the disease in an advanced stage, and in such a condition is not only a danger to public health but also to the rest of the herd. Secondly, tuberculosis is a notifiable disease under the Stock Act. Although most farmers have a fair idea where to look for signs of tuberculosis, one still meets with some rather confused ideas on the subject. Only a small percentage of infected animals show clinical symptoms. A cow may in fact be quite badly infected and seem healthy to all outward appearances, although sooner or later, especially under the strain of intensive milking, symptoms appear. Fortunately, however, we have in the tuberculin test a very sure means of diagnosing tuberculosis in all stages of infection. The incidence of the disease increases with age, being uncommon in calves under one year and commonest in old cows. Lymph Glands As tuberculosis is primarily a disease of lymph glands it is necessary to know something about the position of these to understand the clinical symptoms. The lymph glands are situated in various parts throughout the body. Most of them are internal and cannot be seen or felt. Others are quite superficial and can be readily examined. The position of the superficial lymph glands is shown in the accompanying diagram:— The submaxillary glands are situated at the corners of the lower jaw, one on each side. They are slightly larger than a walnut in size. They can be readily felt, and in fact can be seen as slight swellings in the normal animal, especially when the neck is extended while grazing. The pharyngeal glands are situated deep in at the back of the throat and cannot be felt unless enlarged. When enlarged they cause the symptoms described later.

The parotid glands are situated a little below and slightly in front of the base of each ear. _, , -xx, The piescapular glands are situated about a hands breadth above and in front of the point of each. shoulder. Each is oval in shape, about four inches long, and if the fingers are passed over the skin can be felt slipping oeneatn tnem. The precrural glands are situated in the flanks just above and in front of each stifle. They are similar in size and shape to the prescapular and can be easily felt. The mammary glands are situated above the two hindquarters of the

udder and are not easily felt unless enlarged, _ , , . Tuberculosis of the lungs and generaSed tuberculosis: Tuberculosis of the lungs j s the commonest form in o j der cattle. The beginning of the disease usually passes unnoticed as it j s sow and insidious. When the lungs are involved a dry short cough is noticed, especially after exercise. The cough may later become very troublesome to the animal. ' Discharge from the nose is rare or absent. In calves coughing is nearly always due to lung worm infection, but in older animals a chronic cough, especially with loss of condition, is very suspicious of

tuberculosis. The general effect on the body is at first slight. In fact, animals may remain in good flesh for a considerable time. Infected cows are frequently removed from the herd for

other reasons before symptoms appear. Invariably as the disease progresses there is loss of condition. The coat becomes dry and staring, and the skin hidebound. In the advanced stages

the animal has a debilitated and tucked up appearance generally. Tuberculosis of the throat region: This is the commonest form, in young animals, and is also often present in older cows; either ’ alone or together with infection in other parts. An infected submaxillary gland appears as a rounded ■ firm, swelling which is freely movable beneath the skin and strictly confined to the gland. The swelling develops slowly over a period of months, and shows no tendency to rupture and discharge. One or both glands may be infected. In abscesses of this region, which are not uncommon, the swelling usually develops rapidly and commonly ruptures and discharges. In this case it is more ill-defined, as the soft tissues and the skin are often involved. Another condition which may be confused with tuberculosis is lumpy jaw. Here the bone of the jaw is usually involved as well as the surrounding soft tissues, although the gland may also be infected. In the case of lumpy jaw the swelling commonly ruptures and discharges at several points. Tuberculosis of the pharyngeal gland at the back of the throat is ( more common than that of the submaxillary gland, but is much more difficult to detect in the early stages. It is only when the gland is considerably enlarged that symptoms appear. The animal then holds its head and neck stretched out in a typical manner, and the pressure interferes with breathing and causes a snoring noise. Tuberculosis of other superficial lymph glands. Infected parotid, prescapular and precrural glands may be seen as lumps bulging beneath the skin. Enlargement of these, is often a sign of extensive, infection internally. It is important to know the position of these glands, as lumps in any other parts of the body are not likely to be due to tuberculosis. The early removal of all clinical cases helps to keep down the incidence of tuberculosis, and in any suspicious case application should be made 'to have the cow tuberculin tested. ;

—A. G. BRASH,

8.V.5.C.,

Veterinarian, Christchurch.

CobaH Deficiency- in Sheep and Cattle '

As the result of investigations into the, prevention of bush sickness by the use of cobalt, it is now possible to recommend to farmers in the districts concerned, methods by which they can economically prevent the incidence of the disease. These recommendations are made jointly by the Department of Agriculture and the Cawthrbn Institute, and are available in a bulletin issued free by the Department. . "•/.

Middle-Ear Disease in Pig

Answer to Correspondent

“V.J.R.” (OTOROHANGA):— I have a sick pig aged three months which, although not appearing to be in pain, goes about with its head on the right side, that is, with the right ear lower than the left. It is a little weak, but runs about and has quite a good healthy appetite. LIVESTOCK DIVISION:— The symptoms described are consistent with what is known as middleear disease in young growing pigs. This is due to abscess formation in the middle ear, and has been described as due to vitamin deficiency in the young growing animal. Although the diet of the pig is not given, it is advisable to give the. pig access to young leafy pasture containing clover. It is also advisable in this case to supplement the. diet by the addition of cod-liver oil to the milk or other feeding stuff. About two

tablespoonfuls of cod-liver oil should be added to the feed night and morning for a period of several weeks to build up the vitamin deficiency. It will be necessary to discontinue the use of the oil a few weeks before slaughter, in order to prevent tainting of the meat of the animal at slaughter. Although the use of codliver oil or other vitamin-rich food is excellent in preventing these cases, it

is more, difficult to cure a case when the abscess is already in existence. However, access to green pasture combined with cod-liver oil will build up the constitution, enabling the animal to throw off its present weakness and overcome the ear trouble. If the present weakness is neglected, the animal will later develop paralysis of the hind-quarters.

—MH —KU—UH—IIIi—. MH——MM MH——UM KM-MN— MU , g u m' _ Advisory Service on Veterinary Matters.

Farmers are invited to submit inquiries connected with the health of their stock, and the replies will be published under this heading.