522 HORSE, SWINE AND POULTRY DISEASES 



erences to swine mange in European literature, it would appear to 

 be a common disease there. 



The cause of swine mange is a very small animal parasite, 

 commonly called a mange mite, technically named Sarcoptes 

 scabei, var. suis. The adult female of the mite can be barely 

 distinguished by the naked eye under favorable conditions, but 

 not upon the skin of the hog. The best method of detecting the 

 parasite is to remove the scabs or crusts from the surface of the 

 pig's skin, as these contain very few parasites. Under the crusts 

 the skin should be thoroughly scraped down to the living skin and 

 the material thus collected examined under a low-power micro- 

 scope, when numbers of the parasites will be observed. Both 

 adult and smaller nymphal parasites can be seen the latter 

 being more numerous. It is essential, in collecting material 

 to examine for parasites, that the living skin be scraped to 

 the quick, or, if opportunity offers, a section of the affected skin 

 removed, as the parasites live right on the surface of the skin. An 

 examination of outer skin scrapings seldom reveals parasites. The 

 hog-mange mite burrows in the outer layer of the skin. The adult 

 female lays eggs which hatch into young mites, and these go 

 through the various stages of development on, or in, the outer 

 layer of the skin of swine. 



The symptoms of swine mange are first seen in suckling pigs. 

 They scratch and dig at their sides and neck with their hind feet, 

 and often rub against posts or other objects. After weaning, the 

 pigs do not develop as they should. The hair stands erect, thick 

 crusts or scabs form at the roots of the hair in the region of the 

 withers, top of neck, and about the ears and face. The scabs often 

 extend to the root of the tail, and transverse cracks form in the 

 scabs along the back and even some distance on the root of the 

 tail. It has been reported that sometimes the mange is so severe 

 in suckling pigs as to cause the tips of the ears to shrivel and drop 

 off, and that the tails also slough off from the same cause. This 

 we have not observed, and further evidence is needed to prove that 

 mange is the cause of the sloughing off of portions of the ears and 

 tail. 



The mange mites live on other portions of the hog's body, 

 particularly on the inside of the thighs and along the belly, where 

 small red spots appear, without scabs of any size. The scabs on 

 the top of the neck and shoulders seem to be thicker and more ex- 

 tensive in pigs or shoats from four to eight months old that have a 

 heavy coat of hair. A shoat of this age, when suffering from swine 

 mange, appears stunted, does not eat well or thrive as he should. 

 When the pig gets older, under good treatment the disease appears 

 to lessen somewhat and in adult swine seems to cause comparatively 

 little discomfort. In old hogs there is little scratching, the scabs are 

 not large and the animal does fairly well, although the mange 

 is still present. There are very slight scabs over the shoulders, 

 and a sow will transmit the disease to her suckling pigs by 

 contact. 



