Mange is a common skin infection of dogs caused by mites. It is highly contagious for either animals and humans. Symptoms are intense itching, hair loss, and crusty thickened dry skin. In dogs, there are two significant forms of mange caused by different mites.
1. Sarcoptic mange (Caused by sarcoptic spp)
2. Demodectic mange (Caused by Demodex spp)
Sarcoptes scabiei cause sarcoptic mange in dogs. It is a burrowing mite and round in outline with short 8 legs. They are obligatory parasites. In the most important recognition, characters are the numerous transverse ridges, and triangular scales on the dorsum can see under the microscope.
The predilection sites for the mites are areas such as the ears, muzzle, face, and elbows, but as in other manges, severe infestations may extend over the whole body. The fertilized female mites create a burrow or tunnel in the upper layers of the epidermis and feeding on liquid oozing from the damaged tissues. Eggs lay in a tunnel and hatch in 3-5 days. Then larvae of the sarcoptic mange create small “molting pockets.” Molts of nymph and adults occur in this molting pockets. Sarcoptic mites complete their entire life cycle within 17-21 days.
Pathogenesis of sarcoptic mange.
· Intense pruritis is a characteristic of sarcoptic mange.
· In cases that are neglected for several months, the whole skin surface may be involved. Dog becoming progressively weak and emaciated. A strong soul odor is a notable feature of this form of mange.
Useful diagnostic features of canine sarcoptic mange.
· The edges of the ears are often first affected.
· There is always intense itching (Cases of dermatitis where there is no itch)
Laboratory diagnoses of sarcoptic mange.
· Examination of skin scrapings under a microscope for the presence of mites.