626 THE BOOK OF THE DOG. 



Mange proper. As this disease is caused by parasites that either crawl upon the skin or 

 burrow in under the cuticle, and is quite analogous to itch in the human being, we should much 

 have preferred that name or scabies for the disease. However, in this case the vox populi must 

 rule. 



Like scabies in mankind, mange in the dog is due to the presence of one of two insects- 

 cither the Sarcoptes Canis or the Dermatodectes Canis. The mange caused by the former insect 

 is more difficult to cure than that caused by the latter, for the simple reason that, as the name 

 indicates, the sarcoptes burrows in the skin, while the latter confines its attentions to biting 

 and holding on. Unlike ekzematous affections, mange proper is solely and entirely contagious, 

 and one dog catches mange from another just as one human being ' may catch the itch 

 from another. It is highly contagious, for hardly can a healthy dog lie on the spot where 

 a mangy dog has recently reclined without being affected with the loathsome disease. 



The disease is in this way greatly fostered by the railway companies, to whom great 

 blame is attributable for the disgraceful condition of filth and contagion in which almost all 

 of their dog-boots are kept. It is a well-known fact that these dirty dens are never disin- 

 fected, nor are they washed or cleaned out from one year's end to another a state of affairs 

 to which we have often endeavoured to call the attention of the sanitary authorities, but 

 hitherto in vain. Both mange proper, then, and the disease called follicular mange, are 

 again and again caught by healthy dogs from travelling in the railway boot. This statement, 

 which I have unfortunately little difficulty in proving, ought to be a warning to the owners 

 of valuable dogs not to permit their animals to be confined in that loathsome box, the boot. 



The parasites that may drop or crawl from a dog on to the floor where he lies may live 

 there for several days ; it is well known that on man they will live for weeks, and, although 

 they are not supposed to breed on man, still they excite an irritable disease which for a time is 

 nearly as intolerable as itch itself. 



We have said that mange is contagious, therefore the same causes which produce ekzema 

 such as low feeding, wet and dirty kennels, &c. will not produce it ; nevertheless, filth of all 

 kinds seems to favour the reproductory powers of the parasites. 



" The acari, or parasites," says Mr. Hunting, " are male and female, the latter rather larger. 

 The females measure about ^th of an inch in length, and Trrth in breadth." 



The female runs for some time on the surface along with the males, which are said to be 

 fewer in number, but we think this is doubtful. After cohabitation has taken place, the female 

 acarus burrows into the skin, reappearing with her brood in about a fortnight, having apparently, 

 from the number of her offspring, laid just one egg a day. 



Symptoms. The symptoms are very much like what they are in human itch ; there are at 

 first little red, round spots, on which, by-and-by, vesicles may be noticed, and these may be filled 

 either with serum or with pus. The disease spreads, of course, as the acari extend their operations, 

 and the itching, from the amount of attention the dog pays himself in the way of scratching, 

 must be considerable. This scratching, however, not only increases the disease, by conveying the 

 animalculae to other regions of the body, but also considerably irritates the skin, so that scabs 

 and sores are found ; the hair gets matted with the matter, and soon falls off. 



The regions of the body most commonly attacked are, in our experience, the head, chest, 

 back, and extremities. 



We have really no primary constitutional symptoms in this disorder, the disturbance of the 

 dog's health being attributable to the extreme irritation, want of sleep and rest, and the effect 

 upon the nervous system. 



