Part 85

Symptoms. These are most marked when the animal has been standing with the raw surfaces partially dried and adherent. After moving for some time, and when the surface has been moistened by the exudate there may be little lameness. Until then he moves hesitatingly and stiffly, with the legs abducted or in case of the hind ones straddling. With intertrigo of the pastern or frog, the horse stands on the toe or with the fetlock knuckled forward, and avoids as far as possible a full extension. The same is true of cattle with interdigital intertrigo.

The affected part is hot, perhaps swollen, red, damp and exceedingly tender. Under renewed work, lameness disappears, but becomes worse on standing, and an extensive exudation may occur subcutaneously. If this becomes infected it may result in severe and even destructive lesions, but it usually remains simple and proves readily responsive to soothing and protective treatment. It is most amenable to treatment in dogs and meat producing animals of which no work is required. On the contrary the latter when travelled long distances on foot may suffer severely.

Treatment. First abate the cause. With castile soap wash from the affected part the dried accumulations of sweat, sebum, dust and other matters, remove clay from frog, interdigital space or heels. Rest until the congestion and tenderness subside. Drying applications in the form of dusting powders are usually best: zinc oxide, lycopodium, magnesia oxide, may be dusted in freely after the affected part has been thoroughly exposed and dried. In the absence of these use gloss starch, corn starch, farina or white bismuth. To one or other of these may be added a little alum, lead acetate or morphia. The addition of a layer of surgeons’ cotton is useful, if in a place where it will be retained. Of liquid applications the veterinarians white lotion (zinc sulphate and lead acetate, of each 1 oz. water 1 qt.) is one of the best, being at once sedative and astringent. It may be applied on cotton. Astringent preparations with glycerine are useful but glycerine has the serious drawback of attracting moisture and increasing the secretion when drying is desirable. Carron oil (equal parts of lime water and linseed oil) is most effective and free from this objection. Vaseline alone or medicated with zinc oxide, lead acetate, alum or tannic acid may be resorted to when dusting powders fail. Morphia and camphor have been added when itching is violent.

In intertrigo of the frog or interdigital space the danger of infection from the floor or road is so great that the demand for antisepsis must overcome other considerations. Calomel freely applied to the surface, previously cleansed and dried, is most successful. It may be bound in place by a pledget of cotton and bandage. In other cases alum 5 parts, copper sulphate 1 part, or carbolic acid and tar may be bound to the part.

ERYTHEMA CALORICUM: SOLAR ERYTHEMA. WHITE FACE AND FOOT DISEASE IN HORSES.

England to Africa, on white skins, especially of face. Symptoms: local congestion, swelling, itching, desquamation, during extreme heat: in worst cases fever, dullness, inappetence, costiveness, diarrhœa, head constantly moving, rubbing, vesicles, pustules, excoriations, cracks, fissures, septic ulcers in nose and mouth, submaxillary and pharyngeal swellings, recovery with dermal thickening and tenderness. Diagnosed from petechial fever by the itching, and the absence of petechiæ. Prevention: breed solid dark colors, avoid white skinned in hot climates or work in shade, away from hot winds; sunshade; avoid friction and wetting in sunshine. Treatment: shade, astringents, cool irrigation, vaseline, zinc ointment, lamp black, antiseptics. Tie so as to prevent rubbing.

This has been observed in different latitudes from the cool climate of Great Britain, to the burning suns of Africa, though it reaches its highest intensity in the hotter regions. The parts to suffer are those that are devoid of pigment, as the white star, snip or blaze on the face, the white feet or legs, the white areas in the piebald, and the whole surface in the albino. The white face, however, suffers more than the white legs, apparently because of its more constant exposure, the absence of shadow from the trunk, and the delicacy of the skin and fineness and thinness of the hair.

Symptoms. In slight cases there may be no constitutional disorder, only redness, itching, swelling and subsequent desquamation of epidermis on the white portion of the skin, which may prove persistent so long as hot weather lasts and recover on the advent of cold.

The more violent cases seen in warmer climes, may be heralded by febrile reaction, dullness, prostration, inappetence, constipation and sometimes diarrhœa. The head may be kept in constant movement, the itchy white parts being rubbed on any object within reach, and the limbs are stretched, the front ones forward and the hind backward, with a tendency to rub them with the nose or foot. The skin at first red, becomes later swollen, covered with vesicles which pass into pustules, burst and discharge. Meanwhile the subcutaneous connective tissue is infiltrated and gravitates toward the lowest parts, causing extensive submaxillary swellings and stocking of the limbs. In its worst forms it may go on to necrosis and sloughing, but more commonly the affected part becomes raw, excoriated, cracked and fissured. Sometimes the pituita or even the buccal membrane becomes involved, with muco-purulent discharge. In other cases the absorption of septic products causes inflammation and swelling of the submaxillary or pharyngeal lymph glands. Under favorable conditions, the secretions dry, the sores heal and the exudate is in great part absorbed, but there usually remains some thickening of the affected parts and a diminished vitality of the skin, which renders it morbidly sensitive to sources of irritation.

Severe cases might be mistaken for petechial fever, but there is much more pruritus, and there is an absence of the petechiæ, on the mucosæ, and of a tendency to the extension of the disease far beyond the patches of white.

Treatment. Prevention. This malady should be warded off by breeding or selecting for warm, sunny climes, animals of a solid color, and discarding all with white patches. Animals bred in a cooler climate should not be suddenly transferred to a hot one. When the animal with white face or feet is found in the hot sunny climate, it should be devoted as far as possible to work in the shade (indoors or in mines), or its white patches should be protected against the full unmitigated rays of the sun, and the hot winds. Sun shades are useful or in their absence leafy branches fastened to the bridle so as to protect the face. It is further important to avoid the friction of harness on the susceptible parts, or wetting of them when in the full glare of sunshine. Another obvious precaution is to keep the white patches well covered with lamp black.

When attacked the animal must be placed under cover and eruption treated with cooling astringents, constant irrigation with cool water, or lotions with acetate of lead, tannic acid, alum or sulphate of zinc. When the skin is dry and rigid it may be treated with vaseline, alone or with zinc oxide, lamp black or any one of the astringents above named. Open sores may be treated like ordinary wounds, tense engorgements may be drained by punctures followed by antiseptic dressings, and abscesses may be opened and evacuated.

During the treatment the patient should be tied short to two sides of the stall, and other measures taken to prevent him from rubbing or otherwise injuring the affected parts.

BUCKWHEAT ERYTHEMA: FAGOPYRISM. WHITE SKIN DISEASE.

Form of white face disease, with irritating ingesta, buckwheat, etc., occurs from dried products, no insects; growing potatoes; sunshine; idiosyncrasy. Symptoms: as in white face disease: in winter itching and rubbing: in summer may go on to nervous symptoms. Treatment: stop feeding buckwheat. Give laxative and diuretics. Local treatment as in white face disease.

This may be held to be but a form of the last named affection, in which, however, certain irritating ingesta (buckwheat, maize, wheat), are essential factors in addition to the white skin and strong sunshine. It is seen only on white skins or the white portions of parti-colored skins, while the blacks, browns and other colors usually escape. Black breeds of hogs (Essex) escape under the same feeding and exposure, as do solid colored horses of the darker shades. Of the different food factors, buckwheat (Polygonum fagopyrum, persicare, etc.), is the most to be feared, and the poison seems to be inherent in all the products (green vegetable, dry seeds, bran and straw) and is not destroyed by cooking. Buckwheat cakes sometime produce erythema in man. This excludes the idea of the transfer of a living cryptogam to the skin, though not the theory of pathogenic products of the fungi. The invoking of bee stings and the bites of insects, which are strongly attracted to the buckwheat, is untenable because the affection occurs from the dried seeds, bran and straw, and has been known to break out weeks after the buckwheat was withdrawn from the ration.

In addition to buckwheat, maize and even wheat when liberally fed have been known to cause erythema. Hemminger records a similar outbreak in horses working among growing potatoes.

In addition to the food, clear sunshine is essential and an individual idiosyncrasy. All animals, though equally exposed are not equally attacked.

Symptoms. These do not differ materially from those of the white face and foot disease already described. There are intense redness and tumefaction of the white skin or the white portions, showing prominently in the delicate parts (ears, eyelids, lips), with violent itching, rubbing and sometimes vesicles with yellowish contents, followed by sores and scabs. In the winter season there may be itching and rubbing only. In summer it may become erysipelatoid and extend to the mucosæ, of the respiratory and digestive organs, with hyperthermia, nervous excitement, vertigo, turning in a circle and even spasms and convulsions.

Treatment. This is essentially the same as for the white face and foot disease with this additional that the buckwheat or other offensive ingredient must be withdrawn from the ration, and what remains in the bowels must be expelled by saline or other laxative. Cooling diuretics must follow to eliminate irritant matters that may have been absorbed.

ERYTHEMA FROM IRRITANTS.

Irritant agents of all kinds, even if caustic or pustulant in concentrated forms, may be so diluted as to cause simple erythema. Among chemical agents we have ammonia, lye, caustic acids and salts, iodine, carbolic acid, the various tar products, kerosene, aniline, chloroform, ether, formaline, etc. Of thermic irritants may be named solar heat, fire heat, steam, hot water, hot air, and congelation (chillblains, freezing) the latter being especially common in the digital region when salt has been applied to snow or ice. Vegetable irritants include mustard, capsicum, moulds, euphorbium, rhus, milkwort, the volatile oils, etc. Among animal irritants must be named cantharides, mylabris, potato beetle, insect stings, venom of the irritated toad, liquid discharges from the kidneys or bowels, and discharges from open sores. Even the escape of tears upon the face will cause erythema.

The symptoms in all such cases will vary with the potency of the factor and the susceptibility of the skin. Beside the common symptoms the color and odor of the skin will often yield valuable diagnostic indications. There is the white of muriatic acid, carbolic acid or zinc chloride, the black of silver salts or sulphuric acid, the yellow of iodine, chromium compounds and nitric acid, the well known odors of ammonia, iodine, chlorine, carbolic acid, tar, essential oils, chloroform, ether, formaline, kerosene, mustard, etc.

Treatment is that of simple erythema after one has applied the appropriate antidote to the particular irritant. For the alkalies and carbolic acid use vinegar, for the acids oxide or carbonate of magnesia, chalk or lime water, for iodine and chlorine weak alkaline solutions, for rhus, ammonia or other alkali, or potassium permanganate, and for insect stings and animal venoms, alkalies or permanganates. The caustic salts may demand milk, white of egg, or some other albuminous solution. When no chemical antidote is available, the first step is to wash off the offending agent, and then treat the erythema.

DERMATITIS.

Under this head may be included a class of inflammations of the skin, due mainly or entirely to external causes, not essentially parasitic, and attended by distinct eruptions (papular, vesicular, pustular, etc.). Many of these are but an advance beyond the simple erythematous inflammation, and coincide with it, the one condition being present at one part of the diseased area, and the more advanced and severe lesions at another part. Bearing in mind the frequency of this connection, it will be unnecessary to dwell at length on this class of affections.

=Dermatitis Traumatica. Dermatitis from Mechanical Injury.= Besides the veritant factors already named as causing traumatic erythema, we must here recognize contusions, over-reaching, treads, interfering, bruising and chafing by harness, girths, circingles, hobbles, ropes, traces, twists, and blows with whip, club, chain or rope. Here the source of injury must be removed, by attention to shoeing, harness, etc., and the lesions treated according to their gravity as simple wounds.

=Dermatitis Venenata: Dermatitis Calorica.= These, like the corresponding erythema, come from contact with irritant plants or animals or their products, from excessive heat or cold, and may show any grade of eruption or even gangrene and sloughing. Apart from the washing off of the irritant or venomous matter and the application of alkalies or permanganates in the case of the latter, these must be treated like ordinary sores. In burns, especial value attaches to solutions of sodium bicarbonate, and preparations that will exclude the air. Vesicles may be emptied by puncture and the part covered with cotton soaked in carbolated sweet oil and lime water, or carron oil (linseed oil and lime water) may be freely applied, or a resorcin solution (2:100 water), or a thick varnish of linseed oil and litharge, equal parts, with 5 per cent. of salicylic acid, melted and painted over the surface. A layer of surgeon’s cotton covered by a rubber bandage where admissible, will complete the dressing. In the process of healing, skin grafting may be required. Thin slices of cuticle are placed in the center of the granulating surface, or at intervals and carefully bound in place.