Bovine animals may be attacked by three varieties of mange, all of which have long been known.
SARCOPTIC MANGE.
This is not of any great clinical importance, as it is purely accidental, and only results from the conveyance of sarcoptes from other animals, such as the horse, sheep, dog, goat or cat, to an animal of the bovine species. That the disease does occur, however, is shown by the following excerpt from a report by Professor McFadyean: The animal showed no symptom of skin disease at the time of purchase, but soon after it was brought home it was noticed to be rubbing, and the skin began to assume an unhealthy appearance. When seen in January (four months after purchase) it was rather poor, although it had been in very good condition when sold. Almost the entire skin had become affected, including that of the legs down to the top of the hoofs. There had been extensive loss of hair, and the skin was thick, grey, wrinkled, and dry. At some places it had become thrown into thick folds. Only a few scabs or crusts had formed where the animal had recently rubbed itself. In some scurf scraped from what seemed to be the parts most recently invaded, numbers of acari were without much difficulty found with the microscope.
A good many cases of mange of undetermined character have been reported as occurring among cattle in various parts of England during the last year or two, and in a number of instances the disease was believed to have been contracted during exhibition at a show. It is not improbable that some or all of these were cases of this sarcoptic mange, and in view of its very contagious character it is desirable that care should be taken to exclude from shows animals exhibiting any symptom of the disease.
PSOROPTIC MANGE.
This condition has also been termed dermatodectic mange. This is very rare, and, like the former, of trifling clinical importance.
Causation. It is due to infection with Psoroptes communis (v. bovis). Poor condition, want of grooming, bad hygienic surroundings and general neglect, facilitate its spread.
Symptoms. It commences at the base of the neck, in rarer cases at the sides of the neck, along the withers, and at the root of the tail; thence it gradually attacks the croup, loins, back, shoulders, sides of the chest, and finally all the body with the exception of the limbs.
It produces violent itching, the animal continually scratching itself, even causing raw sores. At first the epidermis is elevated in little miliary points, which may be isolated or confluent, and are filled with serosity. This fluid discharges, gluing together the hairs; it then hardens and produces adherent crusts, which increase in number and size. The skin exhibits large numbers of bare, mangy points; these have irregular margins, and are covered with thick, grey, scaly crusts. The psoroptes are found under these crusts.
The skin becomes hard, dry, fissured and cracked, and sometimes forms large folds on the sides of the neck, shoulders and chest.