Laminitis in its most violent form and early stages, may be confounded at first glance with tetanus, but the high fever, the standing on the heels, the advance of the hind legs under the body, the great heat and tenderness of the feet, the impossibility of standing on one fore foot when the other is lifted and the strong pulsation of the digital arteries, are sufficiently distinctive.
Treatment. For fully developed tetanus no known resort of therapeutics can be relied on. In slight cases that have shown a long incubation and a slow increase and extension of spasm and in those having trismus only, a recovery may be expected. Treatment has been conducted largely on theoretic lines and may be divided into antispasmodic, eliminating and antidotal or antiseptic.
Rest, darkness and absolute quiet are the first and main considerations. A dark stall, with no straw litter, the rustling of which often excites the patient, but rather a little chaff, saw dust or even earth to prevent noise from the feet, and the exclusion of all visitors are essential. As a rule slings should be put under the patient so that he cannot lie, nor drop down, and this becomes more imperative as the disease advances. The aggravation of the spasms when down, and the danger of their extension to the respiratory muscles are far more to be dreaded than the temporary excitement caused by the application of slings. Food should be sloppy mashes, of bran, middlings, oat meal, linseed meal, gruels or milk, or green food may be allowed in moderate amount if the jaws are still movable. It must not be forgotten that digestion is impaired and food that is indigestible, especially fermentescible, or in excess, may arouse fatal colics and bloating, yet in a protracted exhausting disease like tetanus, the strength must be sustained by all means in our power. Pure water should always be accessible. Food and water should be furnished in buckets at a level which will not necessitate either raising or dropping the head to get to them (about 4 feet). The food must be given often, in small quantity to avoid fermentation and spoiling. If noise cannot be wholly excluded it may be an advantage to put cotton wool in the ears. I have seen a mare recover when completely covered with cotton wool under blanket and hoods.
Local antiseptic treatment. Theoretically this is of great value since the microbe is confined to the inoculation wound and by the time the first symptoms appear, the spores have developed into bacilli and are in a condition to be easily destroyed by disinfectants. We can, therefore, by caustics or active disinfectants destroy the infecting microbian colony, and prevent the further entrance of any toxins into the circulation and nerve centres. The principle has been shown experimentally successful in cases of inoculation in the tails of cats and Guinea pigs, and the amputation of these members as soon as tetanic symptoms appear (Kitasato, Babes). Unfortunately in too many cases, when first seen, too much of the marvelously potent toxin has already reached the nerve centres, and these have already undergone such changes, that the disease is likely to go on to a fatal issue in spite of the cutting off of future supplies of toxin. Yet the principle is sound and proves helpful in proportion as it is applied nearer to the time of infection. The most thorough method is the amputation of the infected member, if like the tail or ear it can be excised without ruining the animal. In 1875, Barbillon had success in again amputating the tail, in a case of tetanus after docking. Next to this comes the excision of the wounded tissues, but this can too seldom be effectually and certainly accomplished, and we must fall back on caustics and antiseptics. The actual cautery if thoroughly applied may be trusted to destroy the bacillus along with the tissues, but most of the chemical escharotics unite with the albumen to form an impermeable film, which protects the tissues in the deeper part of the wound against the antiseptic action. Of the different antiseptic applications carbolic acid should be especially recommended as being not only antiseptic, but also an antidote to the toxins as shown below. It has the further advantage of acting as a local anæsthetic, and of not coagulating albumen. Creosote, creolin, lysol or other antiseptic may be used instead and should be applied thoroughly to all parts of the depth of the wound on a pledget of surgeon’s cotton or through a tube. When agents so little destructive are employed they may be continuously applied to the sores for a length of time.
Recoveries have taken place after neurectomy, and after stretching the nerve going to the wounded part, the theory being to check the afferent (sensory) nervous current, and arrest the reflex spasms. The new irritation, however, caused by the surgical wound is to be dealt with, and may itself turn the balance against recovery.
Nervous derivation appears to have been beneficial in some advanced, or partially convalescent cases. One horse after 14 days illness (Taffanel) and another after 21 days (Prud’homme), were castrated, bled freely and slowly recovered. Tisserand gives another case without mentioning the stage of the disease. A horse with advanced tetanus was taken to the seashore and shot. He fell into deep water, swam ashore and made a recovery. But whatever virtue may be in elimination of the toxins by bleeding, in nervous derivation or in the shocking of an unbalanced nervous system, these can hardly be recommended as regular methods of treatment. Yet the older veterinary records contain many instances of alleged benefit from bleeding.
Internal treatment. The whole list of antispasmodics have been tried, with no very satisfactory result. Opium has been extensively employed in spite of its tendency to encrease constipation, and morphia given hypodermically has checked spasm and induced sleep. Hydrocyanic acid and potassium cyanide have shown a decided reducing action on the spasms with the same drawback of favoring constipation. Potassium and other bromides are useful in mild and chronic cases, and may be given in full doses in combination with chloral hydrate. Calabar bean and eserine have been given for their physiological action on the nerve centres, and recoveries have followed their use, but they have little effect on the spasms until the system has been saturated to the point of threatening collapse. Chloroform has the advantage that it can be easily given by inhalation, but while it may be pushed to the extent of temporarily checking the spasms, yet these return at once when the action of the drug is exhausted. Chloroform is always dangerous to a weak or exhausted heart and cannot be given for any great length of time continuously. It is, therefore, very unsatisfactory. Sulphonal and trional have similarly checked the spasms. Gelsemium has given good results in certain mild cases, but it must be pushed to the extent of coming just short of poisonous doses, and the fear of an overdose, together with its failure in severe cases, have prevented its general acceptance. The same end has been sought by the use of nauseating antispasmodic agents, as tartar emetic, tobacco, apomorphia, and lobelia, but though useful in individual cases, these are on the whole no more successful than other agents. Phenacetin, antipyrin, acetanilid and cocaine have respectively received credit for some recoveries.
Chloral hydrate commends itself as being at once a most potent antispasmodic and hypnotic, and an antiseptic. It can, moreover, be conveniently given as a rectal injection, thus avoiding the irritation and excitement of administration by the mouth. Given in this way too, it tends to relaxation of the bowels, instead of constipation. Carbolic acid which can be conveniently given by enemata has an anæsthetic action.
Antiseptic and Antidotal or Antitoxin treatment is more promising, yet it has failed to come up to the full measure of expectation, mainly because the nervous changes have already reached a stage which cannot be undone speedily or at all. Under this heading would come phenic acid (½ oz.) and probably chloral hydrate (1 oz.), already referred to, and the various compounds of iodine which may be here noted.
Iodine Terchloride. Iodine. Behring and Kitasato secured immunity of two months duration, by injecting the animal with a filtrate of a culture of tetanus bacillus, and then injecting at the same point 3cc. daily, for five days, of a 1 per cent solution of iodine terchloride. Roux and Chamberland had similar results by using iodine instead of the iodine terchloride, and maintained the full measure of immunity by repeating the inoculation every fortnight. Here it is evident that the action of the iodine is directly antitoxic or antidotal, when introduced along with the toxins and before they can reach the nerve centres.