Inflammation of the kidneys of the horse is much less frequent than in man - a difference which no doubt finds explanation in the absence in the one of those serious dietetic and alcoholic abuses which are so commonly prevalent in the other.
Chief among these are exposure to cold and wet while the body is heated and fatigued. It is often induced by the habitual administration of cantharides to excite the sexual instinct in travelling stallions. The abuse of diuretic agents, as turpentine, resin, nitre, and oil of juniper, undoubtedly contributes to the number of cases of inflamed kidneys, and it may be accepted as true that the less knowledge carters and grooms possess of the horse, the more frequent will be their use of drugs, and the more powerful those selected.
Inflammation of the kidneys may also result from inflammation affecting the bladder, by extension of the disease along the line of the ureters, or from absorption of cantharides into the blood when applied over large surfaces of the skin for blistering purposes; and it sometimes follows certain forms of blood-poisoning, during which the blood-vessels become blocked, and abscesses develop in the structure of the gland. Severe strains in jumping, and violent efforts at draught, are probably sometimes provocative of the disease.
In this affection the patient shows a frequent desire to stale, but the quantity of urine expelled at any one time is very small, and the total amount discharged in the twenty-four hours is much less than usual. Attempts to urinate are sometimes made without effect, and the penis is unsheathed and retracted from time to time without any attempt to stale being made. Now and again colicky pains appear, and the animal is restless and essays to lie down. The urine is thick and muddy, and sometimes blood-stained, or it may become charged with pus. Pressure over the loins causes the animal to cringe, and the hind-limbs are moved somewhat stiffly in progression.
As the disease advances there is marked constitutional disturbance, shown by the quick pulse, accelerated breathing, increased temperature, hot and clammy mouth, and the occurrence of patchy sweats. Rigors are sometimes present, the face wears a pained and anxious expression, and the mucous membranes of the eyes and nose are intensely reddened.
This should be commenced by the administration of aloes sufficient to open the bowels freely. The diet should be reduced to bran, with which a little boiled linseed may be mixed, and the tea from the latter will prove a most desirable drink, to which, if possible, the patient should be confined. Where pain is severe, opium may be administered in small repeated doses. Hot cloths to the loins will exercise a soothing influence, and enemas of warm water in which a little extract of belladonna has been dissolved will materially aid in subduing existing inflammation.
Where, as sometimes occurs, there are no conveniences for fomentations, the loins may be stimulated by means of soap liniment and strong ammonia (liquid ammonia). On no account are turpentine and cantharides to be used as local applications. Their absorption into the blood would inevitably aggravate the disease.