Definition. Epizootic manifestations. Faulty hygiene, insanitary stables, impure air, defective drainage, fermenting food, overwork, overfeeding, excitement, heat exhaustion, electric tension. Probably complex. Horse, ox, sheep, goat, dog. Microbian factors in man and rabbit. Lesions: meningeal, brain and spinal congestion, effusion, suppuration, circumscribed necrosis, softening, petechiæ. Blood dark, fluid or a diffluent clot. Symptoms: _horse_: paresis, anorexia, dysphagia, mucous congestion, reddish brown: in severe cases, chill, stupor, apathy, debility, palsy, tonic spasms of neck, back or loins, hyperæsthesia, twitching, trismus, hyperthermia, delirium, coma, convulsions, and early death. Duration averages 7 to 15 days. _Ox_, as in encephalo-meningitis. _Sheep_, microbes. _Dog_, dulled senses, stupor, coma, palsy, hyperthermia, heat of head, spasms, etc. Diagnosis: by brain and spinal symptoms; cases in groups. More sudden than tetanus, or rabies, and shows no mischievous purpose, nor depraved appetite: from tubercular meningitis. Treatment: Avoid suspected stable, food, water, or suspicious environment, disinfect, correct local diseases, unload bowels, belladonna, atropia, chloral, bromides, ergot, phenacetin, potassium iodide. Bleeding. Cold to head or back. Derivatives. Sling. In convalescence, regulated diet and tonics. _Definition._ Concurrent inflammation of the meninges of the brain and spinal cord. This appears at times in many horses in the same locality, as in New York in 1850 (Large), in Denmark since 1852 (Stockfleth, Bagge), and in Egypt in 1876 (Apostolides). In Cairo alone about 6,000 horses, mules and donkeys perished. Hence the disease is known as _epizootic cerebro spinal meningitis_. But again it is often seen in scattering or sporadic cases. Add to this that no evidence has ever been adduced that the disease is communicated from one animal to another, and in these days of the parallelism of _epizootics_ and _pathogenic microbes_, we may well hesitate about continuing to use such a qualifying term. Friedberger and Fröhner claim “that a large number of clinical facts have been erroneously reported under the name of spasm of the neck. Rabies, tubercular basilar meningitis, apoplexy, simple encephalitis, and certain poisonings have been confounded with that disease.” They assure us that “cold, damp, chilly weather, hot stables, clipping and overfeeding are of but secondary importance,” but they fail absolutely to tell us what is of _primary importance_ in a causative sense. American writers who have attempted to account for the disease have groped somewhat blindly for causes in the idea of poison. Large charged it on insanitary conditions, poisonous gases, and defective sewerage in cities, and lack of drainage and deficient stable ventilation in the country. J. C. Michener attributes it to foods undergoing fermentation and considers it as a paralysis due to toxic fungi. W. L.