A constitutional disorder, with local manifestations of an inflammatory nature, affecting the lymphatic glands and vessels of the limbs. It is usually confined to one hind extremity, but occasionally involves both, and sometimes attacks a fore one.
Predisposition to this disease is especially marked in heavy coarse-bred draught horses with a thick skin, round fleshy legs, and lymphatic temperament. It may, however, and occasionally does, attack the lighter breeds, but this is of comparatively rare occurrence. Lymphangitis seldom appears before the adult period of life has been reached. Animals out on grass enjoy an immunity from it, and it is only when they are housed and liberally fed on highly stimulating food in the course of active work that the disease presents itself.
Under these conditions the disorder appears to be excited by insufficient exercise or a temporary respite from work; hence it is sometimes termed " Monday morning disease", from the fact of its frequent occurrence after Sunday's rest. The intimate cause of the malady cannot be clearly stated, but it would seem to have its origin in some vitiated state of the blood, either resulting from imperfect assimilation of the food or the too tardy elimination from the system of the waste products of the wear and tear of the body.
Two groups of symptoms are clearly manifested in this disorder; one group has reference to the diseased limb, and the other to the general system. In respect of the former it is observed to become suddenly enlarged, hot, and painful. The swelling commonly extends from the foot to the stifle, but may be less extensive in the milder forms of attack. The animal shows intense lameness, and will sometimes hold the leg suspended in the air as evidence of pain. The glands in the groin are swollen, and in the more severe cases an oozing of a straw-coloured fluid appears upon the skin.
The constitutional symptoms are ushered in by rigors or shiverings, an accelerated pulse, and hurried breathing. The temperature rises two or three degrees above the normal standard. The mouth is hot and clammy, the bowels constipated, and the urine thick, and somewhat dark in colour, and loaded with solid matters. Under judicious management the fever symptoms subside in thirty-six to forty-eight hours, and the local symptoms show signs of abatement.
As a rule to which there are but few exceptions, a bold dose of aloes in the form of a ball should be promptly administered, and while waiting for its effects relief may be afforded by warm fomentation and the employment of soothing emollients to the swollen limb. The anodyne effects of warm water may be increased by the addition of opium and solution of the acetate of lead, and the emollient chosen may be improved by the addition of extract of belladonna or cocaine.
Diuretic agents may here be employed with great promise of success, as they stimulate the kidneys to carry off the morbid material in the blood. Nitrate and bicarbonate of potash is a convenient form in which to give diuretic drugs. Sometimes benefit results by a free scarification of the swollen limb, i.e. making a number of small punctures through the skin with a fine lancet.
Movement during the first two or three days is very painful, and although a reduction of the swelling and greater mobility of the limb is the immediate result, it appears to increase the inflammatory action afterwards. With the first subsidence of pain and swelling, short walks at frequent intervals may be recommended as reducing the liability to permanent thickening. The appetite is generally impaired at first, and should not be indulged immediately when it returns; a low diet during the period of convalescence being all-important in the matter of treatment. Grass and young vetches or other green food should be supplied, if obtainable, and corn withheld until a good deal of exercise can be taken. In the absence of green fodder, bran mashes, carrots, and a moderate amount of hay should be given. It invariably results that more or less permanent thickening remains after the acute symptoms have subsided, especially in the more depending parts of the limb. This, however, may be in some measure obviated by repeatedly subjecting the limb to brisk rubbing with a straw wisp and afterwards to a course of massage. Increased susceptibility usually follows the first attack. Animals so predisposed require special attention and management. In this connection walking exercise should be given whenever a rest-day comes round, and the food ration should be diminished. An aperient dose of medicine, given every three or four months, will greatly assist in warding off an attack.
Fig. 209. - Lymphangitis.