Symptoms. At the outset the animal may be seen to move rather stiffly, and the skin is found to be hot, thickened and if white reddened. Soon a close observation may detect the eruption of vesicles, or simply an oozing of a yellowish or bloody serum which concretes around the hairs forming an encrusted covering for the part, holding the hairs erect and bristly, and even lifting them out of their follicles. Cracks also appear in the depth of the fold, leading to a more abundant exudate, and the disease may extend around the whole surface of the limb.
In the more acute cases this may be followed by more or less depilation, dessication and recovery, but too often the condition becomes chronic, the thickened, encrusted or squamous skin continues to exude, crack and cover itself with crusts, under which the decomposing liquids macerate and irritate the exposed cuticle, and engorgment of the whole limb with hyperplasia of the connective tissue and lymphatic plexus and vessels is the result. This hyperplasia of the skin and connective tissue (elephantiasis) is also a common result of lymphangitis.
Treatment. As in other skin affections attention must first be given to removal of the causes. Ensure cleanliness, pure air, regular exercise, non-stimulating food, the avoidance of cold water, melting snow, soapy washes and all other sources of irritation. Deep mud, especially if charged with lime, sharp sand, decomposing organic matter or other irritant, is particularly offensive.
Hand-rubbing (massage) of the limbs and evenly applied light bandages are often of the greatest value in dispersing or obviating swelling.
The slighter attacks may be met at the outset by bland ointments or dusting powders and rest from all but necessary exercise. Dressing with iodoform may bring about a recovery in a few days. Starch and oxide of zinc, boric acid, magnesia carbonate, bismuth or lycopodion may give good service. Lotions of lead acetate, tannin, iron sulphate, alum, potassium permanganate or pyoktannin may be used as in other forms of eczema. In obstinate cases green soap followed by stimulating ointments or liniments, tar, oil of white birch, Canada balsam, turpentine and glycerine, oil of cade, etc., will often serve an excellent purpose. In these advanced cases an alterative such as arsenic may be employed.
ECZEMA OF ALIMENTARY ORIGIN IN CATTLE.
STARVATION MANGE. STALK DISEASE. MALT ECZEMA. POTATO ECZEMA.
In low condition: erythema, hæmorrhagic extravasations, or vesicles on tail, lips, fore legs, udder. Trombidium holosericeum. Malt or potato eczema: marc eczema on legs and body. Causes: feeding on marc only, skins, green potatoes, fermenting. Attack in ratio with marc eaten. Worst on new stock, and feeding cattle. Calves have diarrhœa, children eruption. Bean trefoil and milk sickness act similarly. Solanin. Unaffected by boiling. Season. Field. Chlorophyl. Narcosis absent. Is brain adaptable? Other ingredients inoperative. Eczema ceases with change of food: is not inoculable. Symptoms: fever, costiveness, inappetence, red mucosæ, weeping, stringy salivation, debility, emaciation, black diarrhœa. May lie with extended head, grinding teeth, tympany, lethargy, coma. Pig and dog vomit. Abortion. Redness, swelling, stiffness on pasterns: may extend to whole body: exudations: thick crusts: erect or shed hairs: rigid thickened, folded, cracked skin, buccal mucosa may suffer: abscess, sloughs. Mortality slight and up to 20 per cent. Lesions: congestions of small intestine, brain and muscle. Treatment: stop or lessen the marc adding grain: turn to pasture: locally bathe, cold or tepid: lead lotions: dusting powders: tannin: blue stone: creolin: cresol: tar or birch oil: carbolic acid.
The skin of cattle seems to suffer more than that of other animals in connection with the ingestion of poisons. In starved or very low conditioned animals, eruptions are met with which may be in the form of a simple erythema, a hæmorrhagic extravasation in spots, or an eruption on the end of the tail in the form of epidermic concretions or pustules (impetigo). Among the vineyards it is common to find an eruption with papules and vesicles on the lips, fore legs and udder of cows which were fed on the succulent young shoots and leaves of the grape vine. In cases of this disease, Railliet and Moreau have found a great number of the silky trombidium larvæ (harvest bug), and accordingly attribute the affection exclusively to their attacks. The growth of the vine on the warmest and sunniest exposures, the most favorable to the propagation of this acarus, gives much support to this conclusion.
Malt or Potato Eczema. On the continent of Europe where potatoes are largely used for distillation and the production of starch, herds of cattle are fed often almost exclusively on the refuse or marc, and in such herds an eczematous eruption of the legs and exceptionally of the body is a familiar occurrence.
Causes. The disease has been definitely traced to an exclusive dietary on potato marc, and still more so to the skins, to tubers rendered green by exposure to the sun, and to the distillery potato refuse which has undergone fermentation. Thus 80 litres of the pulp daily without dry food will determine a violent attack in the animal consuming it, while the animal consuming 40 litres has it much milder (Friedberger and Fröhner). It attacks animals living in the best conditions of cleanliness and pure air, and the essentially toxic quality of the cause may be deduced from the fact that newly bought animals, which are not yet habituated to it suffer the most, that fattening cattle are the common victims, while work oxen which perspire more freely and milch cows escape, yet calves fed upon their milk may suffer from diarrhœa and infants from a cutaneous eruption (Johné). The poison it is to be inferred is eliminated in the milk. Similar examples of the protecting of the milch animal by elimination of the poison through the milk are found in bean trefoil (cytisus) which poisons the milk while proving harmless to the goat which yields it, and the poison of milk sickness which is deadly to cattle which are not giving milk, and harmless to the milch cow, yet deadly to those that consume her milk.