Puscarin and Vesesco have shown that the virus is rapidly weakened by heat up to 60° C. at which point the virulence is destroyed. It becomes easy therefore to secure in this way a toxin uncomplicated by any living microbe.
Theoretically the sterilization and use of infecting nervous substance, should share with the Pasteur method the advantage of the selective action of the medullary matter in uniting with the toxins and robbing them to a greater or less extent of their toxicity. It has the additional recommendation that it introduces no living germ, and thus obviates any possible danger of the propagation of disease through the animal operated on.
Fernandez claims an immunity from rabies for dogs that have survived the bite of a viper. Many facts and experiments are adduced in support of this.
TETANUS.
Synonyms. Definition: infectious disease, due to bacillus, and shown by tonic spasms of groups of voluntary muscles. Animals susceptible: warm-blooded animals—dogs and chickens least: ⅔ds solipeds, ⅐th cattle. Pathology and Causes: Bacillus tetani: 4 to 5µ by 0.2 to 0.3µ, often enlarged by spore at one end; anærobic, liquefying, tardily motile, until spore forms, grows in ordinary, alkaline media under hydrogen, death point 60° to 65° C. (140° to 149° F.), for spores 80° C. (176° F.), for an hour, dried it lives for years, in putrid matter 2½ months, stains easily, saprophytic in garden mould, in ingesta of man and horse, abundant in tropics; infection local, killed by oxygen in blood, toxins tetanize: tetanin, spasmotoxin, toxalbumin, diastase; spasms first local near wound, then abruptly general, intravenously causes general spasms first, theory of fermentation in blood; changes in nerve cells, neuroglia, ependyma, peripheral nerves: muscles soft, pallid, red, ruptured fibres, ecchymosis; rigor mortis early, marked: sarco-lactic acid. Accessory causes: traumas and their causes, parturition, umbilical infection, alimentary. General symptoms: incubation 3 to 15 days, minimum 6 hours; tonic contraction of muscle groups of locomotor system beginning near infection wound,—trismus, orthrotonos, opisthotonos, emprosthotonos, pleurosthotonos, ocular muscles; costive, difficult urination, hyperæsthesia, irritability, perspiration, hyperthermia, mastication, deglutition, sucking. Symptoms in horse: neck raised concave above, nose elevated, nostrils wide, eyes sunken, haw protruded, ears rigid, pricked, facial muscles rigid, prominent, mouth drawn back, muscles of back hard, tail elevated, trembles, limbs extended outward, stiff, stilty, jaws clenched or open slightly, stands. Symptoms in cattle; sheep and goat; swine; dogs; birds: Course: violent cases with short incubation are rapid and fatal; mild ones with prolonged incubation hopeful; cattle slow, sheep, goats and dogs acute. Mortality: sheep and pigs 100 per cent.; horses 75 to 85; cows 70 to 80; lambs very fatal. Death from asphyxia, hyperpyrexia, or exhaustion. Lesions: trauma, often healed; congested nerves, gray horns of myelon, increase of cells and granules in nervous matter of cord, corpus striatum, cerebellum; blood extravasations at torn muscle fibres, intestinal and cystic congestion. Diagnosis: from strychnia poisoning by slow advance, and persistence of spasm; from rabies by absence of bite, the continuous masseteric spasms, by absence of resentment, mischief, hallucinations or depraved appetite; from rheumatism by the persistent trismus, hyperæsthesia and excitability; from meningitis by the trismus, perfect mentality, absence of clonic spasm; from tetany by shorter and less perfect remissions, failure to develop under nerve pressure, or improve under thyroid extract; from laminitis by the absence of high early hyperthermia, heat and tenderness of the feet, and advance of hind legs under the body. Treatment: best in slight cases, after long incubation, with slow progress; antispasmodics; rest, darkness, absolute quiet, no litter, nor visitors, slings, sloppy food, gruels, milk, green food, at level of manger; clothing to favor perspiration; excision or antisepsis of wound, carbolic acid, bleeding, opium, prussic acid, potassium cyanide, bromides, physostigma, eserine, chloroform, sulphonal, trional, tartar emetic, tobacco, apomorphia, lobelia, phenacetin, acetanilid, cocaine, chloral, phenic acid, iodine terchloride, iodide of potassium, orrotherapy, antitoxin; best as a preventive, value decreases with development of disease; cerebral injections; brain emulsion; use up toxins in blood; no use if nerve centres are already in combination with toxins, only to ward off fresh toxin. Toxins produce leucocytosis. Prevention: disinfection of all dirty wounds, injections of phenic acid, or iodine; remove foreign bodies, use muriatic and carbolic acids; antisepsis of navel; disinfection of stables, feet, careful shoeing; immunization.
Synonyms. Lockjaw. Trismus.
Definition. An infectious disease of animals and man, characterized by tonic spasms of the voluntary muscles in a given region or more generally, with exacerbations, and dependent on the bacillus tetani.
Animals susceptible. Immunity cannot be claimed for any class of warm blooded animal. Experimentally the dog and chicken prove among the most refractory, in keeping with the comparative insusceptibility of the last named animal to strychnia, but neither can be held to be in any sense immune. Inoculated frogs become tetanic if the temperature is maintained above the normal standard. In 208 cases in domestic animals recorded by Cadiot and Hoffmann, 140 were in horses, 10 in mules, 5 in asses, (solipeds, 155), 28 in cattle, 9 in sheep, 5 in goats, 5 in pigs, and 6 in dogs. Such statistics are liable to prove misleading when we have no means of comparing them with the members of the different genera from which the cases were drawn and the relative exposure of each genus to traumatic lesions (infection atria). Solipeds lead with practically ⅔ds of the entire number of cases, but these were presumably the most numerous of the domestic animals, and preëminently the work animals and therefore the most liable to traumatism. Cattle follow with ⅐th of all cases but here again the large numbers to be drawn upon, and the proportion of work oxen and wounds, are to be considered. The omnivora and carnivora are comparatively little susceptible and among these the chicken may be included. The omnivorous rat is quite susceptible.
Tetanus occurs in 1 per 1000 sick horses in the Prussian army (Friedberger and Fröhner), and in 1 per 3000 sick in that of Wurtenburg (Hering). It is so prevalent in San Domingo that a gelding costs twice as much as a stallion (Wagenfeld). Heat and filth favor its preservation.
In man tetanus is most frequent as the result of wounds (in feet and hands) which are most likely to come in contact with the soil, and it has visibly decreased in connection with the general adoption of antiseptic surgery.