Part 91

PITYRIASIS IN THE DOG AND CAT.

Head, neck and back of overfed, old house dogs. Symptoms: floury dandruff, with little itching or redness, on limited areas; in cats over the whole back, where stroking causes electric development, the collecting of the hair in tufts, and insufferable irritation. Hair constantly shedding without necessarily bare patches. Treatment: simpler, restricted diet, correct internal disorders, laxatives, arsenic, locally solutions of alkalies, borax, potassium sulphide, sulphur iodide, baths.

In dogs this affection attacks especially the head, neck and back of pet and house dogs gorged with dainties, and particularly in those that are already becoming aged. The affected parts are covered with a floury or branlike product lying upon a dry surface usually devoid of irritation or congestion, though it may be distinctly congested and reddened, and even the seat of pruritus. The affection is usually confined to limited areas, more or less destitute of hair, and without showing a disposition to active extension. In the cat, however, it may affect the whole dorsal aspect of the body, being associated with extreme electrical susceptibility, so that on being stroked the hair at once collects in tufts, crackles, and in the darkness sparkles, and the animal at first fawning on the hand, will fly at and scratch it after a few strokes. The scaly product is excessive and drops off abundantly when handled, without, however, leaving thin or bare patches.

Treatment is mainly in the line of a simpler and more natural diet, the avoidance of sugar and cake, the correction of disorders of the digestion, or of the hepatic or urinary functions, the exhibition of an occasional laxative, and of alteratives, especially Fowler’s solution.

Locally, alkaline lotions, carbonate or bicarbonate of soda or potash, borax, sulphide of potassium and iodide of sulphur are often useful. A moderately strong solution of common salt with glycerine in water is an useful alternate, and a warm saline or bran bath may soften the skin and modify its nutrition.

CONTAGIOUS PUSTULAR DERMATITIS IN THE HORSE. ACNE.

History. Cause: bacillus. Symptoms; incubation 6 to 15 days, skin tenderness, heat, swelling like peas, hazel nuts, vesicles, pustules, exudation, concretions among hairs, depilation, healing in 15 days. Leaves white spots with lighter hair. Extension by grooming: general eruption: subcutaneous swelling, sloughs, delayed healing. Lymphangitis. Diagnosis: from chaps and bruises, from horse pox, from impetiginous eczema, from urticaria, from farcy. Prevention, quarantine new horses, separate diseased, disinfect skins of the unaffected, disinfect stables and harness. Treatment: soapy wash: germicide lotions.

This has been largely described as an imported disease thus on the European continent it is the English variola, and in England the Canadian contagious pustular affection. Yet the first authentic account dates back to 1841–2 when Goux found it attacking an entire squadron of the French army in a fortnight. Axe described it in England in imported Canadian horses in 1877, and Weber observed it in the same year on the continent, where it was attributed to imported English horses. In 1883 it was noted by Schindelka, in 1884 Siedamgrotzky inoculated it from the horse on two rabbits and two Guinea pigs, and to horse and goat. The rodents developed a “malignant œdema” at the point of inoculation and died in six days. Grawitz and Dieckerhoff cultivated the bacillus on ox or horse serum and found it 2μ in length, dividing by segmentation into round or ovoid refractive spores, which may remain connected as diplococci or short chains and which color deeply in fuchsin. It grows most rapidly at a temperature of 37° C., growth ceases at 17° C., and it is destroyed in half an hour at 80° to 90° C. Preserved, dry, it remained virulent for four weeks and produced the characteristic eruption when rubbed on the skin of the horse, ox, dog, sheep or rabbit. It proved fatal to all rodents, including white mice. The microbe is found abundantly in the pus and crusts and is easily shown when these are treated with potash. It produces no putrid fermentation.

Symptoms. When inoculated it had an incubation of six to fifteen days followed in mild cases by swelling heat and tenderness of the skin with collection of the hair in erect tufts. Next day there are rounded elevations like peas or hazel nuts, discrete or confluent on the swollen patches. These nodules, at first firm and resistant soon become soft in the center, forming vesicles and finally pustules, which burst in five or six hours and exude an abundant liquid which concretes in a thick amber colored mass. The hairs in the center of the resulting raw surface are easily detached leaving bare spots the size of a dime, with often times a slough attached in the center. When this is finally eliminated the surface gradually cicatrices and recovery may be complete in fifteen days. The skin remains long dappled from the partial discoloration of the epidermis in the seat of the pustules. The malady is local and hyperthermia is rarely seen. The submaxillary and pharyngeal lymph glands are usually swollen and indurated, but this disappears speedily after the subsidence of the eruption.

In certain cases the extent of the primary eruption is greater from the first, or it extends through reinfection by combs, brushes and rubbers used in grooming or by friction by the harness, the affected skin is hot, painful, congested and thickened throughout its entire substance, the pustules are much more numerous, often confluent, and may even implicate the subcutaneous connective tissue. The crusts formed on the sores may acquire a breadth of 1 inch to 1½ inch. Considerable abscesses may be formed and the lymph glands communicating with the affected part are hot and swollen. Even after the opening and discharge of the abscess, the base of the sore remains indurated and indolent, and centres of softening and caseation may appear so that healing is delayed for one or two months or more. In such cases extensive cicatrices remain after recovery. Lymphangitis is a common accompaniment with even abscess of the lymphatic glands.

Diagnosis. From chafing and bruising by the harness, this is easily recognized by its appearing also on other parts than those covered by the harness, by the development of the characteristic pustules, by its following a regular cycle of eruption and subsidence covering a definite period of usually 15 days, and by the indisposition to maintain itself indefinitely under the friction of the harness.

From horsepox it is distinguished by the habitual avoidance of the common seats of election of that disease (heels, lips, nostrils, buccal and nasal mucosæ, lips of the vulva), by the absence of hyperthermia, and by the comparative absence of the remarkable amber-like concretions which characterize horsepox in the lower limb.

From impetiginous eczema it is diagnosed by its contagious and inoculable properties, by the absence of the early falling of the hair from the circumscribed rounded nodules, and by the absence or moderate character of the pruritus which is usually intense in the eczema.

The eruption of urticaria appears much more suddenly, shows no tendency to form vesicles nor pustules, is not inoculable, and subsides often as suddenly as it appeared when the irritant food materials have been expelled from the alimentary canal.

From acute farcy it is distinguished by the moderate degree of the implication of the lymph vessels and glands, by the white creamy nature of the contents of the pustules, as compared with the glairy, oily nature of the farcy discharge, by the absence of coincident nasal ulcers, submaxillary nodular swellings or other lesions of glanders, by its short course and tendency to spontaneous early recovery, and by the absence of reaction under the mallein test.

In all cases the known prevalence of the contagious pustular dermatitis in the locality, or the introduction of strange horses which exhibit sequelæ of the lesions will assist greatly in the diagnosis.

Prevention. If animals are introduced from an infected or unknown locality they should be kept apart from others for two weeks. In a stable where it has already appeared the diseased and healthy should be carefully separated and the skins of those as yet unaffected may be washed with a solution of mercuric chloride (1 ∶ 1000) or creolin (1 ∶ 100). The walls of the stable should be whitewashed, and all stable utensils disinfected in boiling water or one of the above named antiseptics. The harness demands particular attention.

Treatment. This is essentially germicide. After a soapy wash, any one of the usual disinfectants may be used: aluminum acetate, (1 ∶ 15), mercuric chloride (1 ∶ 1000), carbolic acid (1 ∶ 50), creolin (1 ∶ 50), copper sulphate (1 ∶ 50), etc. Lead acetate 2 parts, alum 1 part and water 50 parts, has been found to be effective.

PEMPHIGUS IN HORSE, OX, PIG AND DOG.

On rare occasions the horse or ox is attacked with a skin eruption, attended with the formation of bullæ or blisters, from the size of a hazel nut to a hen’s egg, or larger. It is sometimes shown sporadically and at others appears at once in a large number of animals in the same herd. The causes are obscure, yet the enzootic appearance of the affection is suggestive of a common factor entering probably by the food. Loiset and Seaman have recorded enzootic outbreaks in cattle and Dieckerhoff in the horse.

Symptoms are cutaneous congestion with the formation of swellings like a walnut, but exceptionally as large as the fist, on the head, neck and thorax, which in 2 to 4 days form a large central vesicle, with yellowish serous contents. Cases in the ox (Loiset, Seaman) had a similar eruption on the loins, quarters and hind limbs, some of the swellings attaining the size of a hen’s egg, and with similar contents. Later these ruptured, crusted over and healed, with, for a time, a smooth glistening surface. Winkler records cases in swine and Schneidemühl in dogs, but the condition is rare in both animals.

Treatment. To a nutritious, non-stimulating and easily digestible diet, may be added a course of arsenic and, in low condition, of bitters. Locally dusting powders of zinc oxide, boric acid, starch and lysol. Should the exudate form these into hard cakes, they may be replaced by carbolized oil or, better, a 5 per cent. mixture of ichthyol in vaseline.

CRACKED HEELS IN HORSES. SCRATCHES.

Special susceptibility and exposure of posterior pastern region. Divisions. Causes: local irritants, decomposing manure, chill water, slush, mud, pools of liquid manure, septic irritation, stones, sand, lime in mud, salted snow or ice, washing heels, caustic soaps, stubble, clipped or singed hair, stocking of limbs, lymphangitis, sprains, arthritis, anæmia, cardiac, urinary or hepatic disease, parasites, heavy bedding, constitutional predisposition. Symptoms: redness, heat, tenderness, swollen, erect hairs, lameness, knuckling, or exudate, crusts, scabs, abrasions, chaps, fissures, ulcers, loss of pliancy, engorgment of limbs, fœtid secretion. Prognosis according to cause. Treatment: remove causes, give rest, cleanse limb and stable, astringent antiseptic lotions, sulphurous acid, carbolic acid, creolin, lysol, pyoktannin, chrysophanic acid, moderate laxative food, diuretics, arsenic, bandaging, hand rubbing, exercise.

The affections of the heel or posterior part of the pastern in horses are largely modified by the anatomical character of the skin in this region, and the special exposure to inimical agents, so that it is convenient to consider them under special headings, even though the eruption may be of the same kind with that seen in other parts. The dermatitis of this region, which are not primarily contagious may be conveniently divided into 1st, such as are unattended with free secretion, and 2d, those that implicate the sebaceous glands and are marked by an offensive discharge. Cracked heels belong to the former category.

The causes are extremely varied, consisting in the application of irritants of many kinds, to the susceptible skin in a system too often already predisposed to skin disease.

Standing on reeking dungheaps, or on heating manure in filthy stalls subjects the heels, and especially the hind ones, to ammonia and other irritating fumes, and when taken out to the cold air, chill water and mud, the sensitive parts suffer. Again in the farm yard and even in neglected stalls the hind feet are immersed in pools of liquid manure, the ferments and toxic matters of which dry on the skin, attack the surface and determine septic congestions and inflammations. On country roads where there is no pretense of pavements, or macadam, the mud in spring and fall is a source of great irritation on certain soils which contain small flat stones, pebbles or sand, or in which lime or decomposing manure is a prominent feature. Standing in snow or slush, especially if chilled by salting, produces partial or complete congelation with the result of chillblains or even more active and destructive inflammation or sloughing. The habit of washing the heels and allowing them to dry spontaneously in the stall is only less injurious by the chill induced. This is still further aggravated by the use of caustic soaps on the already tender skin. The lighter breeds of horses, devoid of long hair on the pasterns, though less subject to the greasy secretion, are even more exposed to chills and direct injuries, and suffer readily and often persistently from erythema and cracks. In many cases trouble comes from the ends of stubble and other vegetables acting on the skin. A common fault is the close clipping and even singeing of the hair in the hollow of the heel. The stiff, bristly ends of the hairs on one fold of the pastern continually prick the skin of the adjacent fold when the animal is in motion and not only is this irritating to the healthy skin, but it becomes incomparably more so when that is congested and tender. Even in summer the deep dust on unpaved roads, mixing with the normal secretions of the heel, rolls into semi-solid masses between the folds and proves the more irritating, the greater the admixture of sand or solid bodies. A common cause is the stocking of the limbs, with the attendant congestion, distension and debility of the skin. This may be due in its turn to a great variety of proximate or remote causes, lymphangitis, sprains, arthritis, osteitis, anæmia, cardiac, urinary or hepatic disorder, parasitisms, etc., so that accessory causes must often be widely sought. Even an excess of straw around the hind limbs will cause stocking in some animals which escape on bare pavement. Finally we must take into account that constitutional predisposition in some animals that makes them liable to inveterate skin diseases under the slightest causes.

Symptoms. In the milder forms there may appear a redness, with heat, tenderness and swelling in the hollow of the pastern, the hairs stand stiffly erect, and the surface may be perfectly dry. The affected limb has the pastern more upright than the others and the fetlock starts slightly forward. In a nervous, sensitive horse the skin is so tender and rigid, that the animal can hardly be persuaded to use the limb, and goes dead lame for a considerable distance until it has become more pliant.