Experiments made on other dogs with the larval and mature ticks, fully confirmed the conclusion that the immature insect was harmless. A 14 days old puppy infected by mature ticks died on the 11th day so that the immunity of the other puppies cannot be due to a milk diet, as in the case of calves and Texas fever. Intravenous inoculation with the infected blood invariably conveyed the disease.
Symptoms. On the third day after inoculation the dog is dull, prostrate, apathetic and drowsy, refuses food and shows thirst. Temperature may reach 103° to 106° F. On the fourth day the mucosæ assume a yellowish tinge, and by the fifth this has encreased to a deep chrome yellow, which involves any white portions of the skin as well. Hæmoglobinuria is now well developed, the liquid being often as dark as claret, and the patient may lie perfectly prostrate, giving off an offensive odor from the skin, lungs, and especially from the mouth. The tongue is furred, the teeth dirty, and the gums may be congested or even ulcerated. Emaciation advances rapidly. The temperature may oscillate from day to day or it may rise steadily to a climax, and then descend suddenly when collapse occurs. In all cases the protozoön is found in the red globules, or free in the blood. In the worst cases the red globules may be so reduced in number that they can scarcely be found. Death comes usually by collapse. In some instances the hæmoglobinuria may be absent yet the disease advances to a fatal result.
Lesions. The carcass is usually shrunken and emaciated and exhales a fœtid odor. The mucosæ, white skin, and all naturally white structures (fat, connective tissue, fascia, tendons, ligaments, brain, spinal cord, etc.), are stained of a deep yellow. The muscles, liver and other darker tissues are of a mahogany yellow; petechiæ appear on the heart and serosæ; the liver is greatly enlarged and friable (10 lbs.) the spleen is swollen, gorged with blood and a soft, black, bloody pulp; the stomach and small intestines are empty, yellow and sometimes congested. The large intestines show muco-enteritis throughout with an abundant rusty red exudate. The kidneys are yellowish with cortex somewhat pale. The bladder also yellow contains dark colored urine. The red blood globules are greatly diminished in number, many are crenated, broken up and distorted and they contain the piroplasma in large numbers.
No system of treatment has proved successful. Essays would naturally be made with quinia and other antiperiodics.
Prevention would naturally be sought in keeping dogs off from the uncultivated land and brush during the tick season (summer, autumn), in clearing and cultivating the tick infested pastures, in drainage, or in smearing the coat of the dog with the oil of tar liniment or other insecticide when he goes hunting.
PALUDISM IN HORSES.
Alleged identity with ague. Geographical distribution. Points of difference from ague. Causes: low, damp, undrained, inundated localities, hot seasons; inoculation, congenital. Symptoms: restless, drowsy, stiff, shivering, hyperthermia, tremors, cough, frothy, rusty expectoration, excited breathing and pulse, anorexia; puffy, petechiated eyelids; epiphora; dyspnœa: albuminous, yellow or red urine with casts: hæmoglobinæmia: colics, constipation, fœtid diarrhœa. Death in a few hours to 6 days, or months. Lesions: reduction in blood globules, crenation, watery blood: petechiæ: enlarged, blood-gorged liver and spleen; congested, swollen, softened, kidneys; congested lungs with extravasations: in chronic—anæmia, dropsies, lung hepatization and suppuration. Prevention: keep susceptible horses from low, infected lands from June to November and from their water: protect from insect enemies. Treatment: quinia sulphate or bromide, hot baths, etc.
Cadeac and others describe an intermittent or remittent febrile affection of the horse, as identical with ague, and due, they allege, to the presence in the blood of the plasmodium malariæ of Laveran.
Geographical Distribution. It has been observed on the low marshy grounds of Sicily, the Danube bottom lands, Algiers, Tonkin, Madagascar, Soudan, Senegal and Cochin China (Dupuy, Lenoir, Pierre, Colin). Dr. Gelston informs me that in the American cavalry in the Philippines extensive losses are sustained from this disease.
Microbiology. The causation of the disease is attributed to the plasmodium malariæ, which is carried by the Anopheles and inoculated in the skin of man, in malarious regions at night, but we are confronted with the difficulty, that accepting the alleged identity, the disease in the horse should be coextensive with that occurring in man. Yet we have in the New World many areas characterized by the all but universal prevalence of intermittent fever in man, and at the same time by its entire absence in the case of the equine races. It may further be considered that protozoa, found in the red globules of birds, were at one time considered identical with those of malarious fever, but have been demonstrated to be entirely different so far as pathogenesis is concerned. There is every presumption that the protozoa of the red globules found in the horse in this disease are also distinct pathogenically.