Sarcoptic Mange Cats And Dogs

As will be described below in the life cycle of Sarcoptes scabiei, these mites like to tunnel in the upper layers of the skin. When they do so they cause the host to become sensitized and an intense inflammatory reaction occurs. This results in an aggravating itch for the infested host. The constant scratching results in hair loss and damage to the skin by self-mutilation. Although the lesions start on the thinly haired areas such as the ears, muzzle and around the eyes, if let go the condition can spread over the entire body. Serum ( the clear component of blood) seeps out of the tunnels to the surface of the skin and causes thick scabs to form. Secondary bacterial infection usually occurs causing pus to accompany the scabs. "Not a pretty picture".

Diagnosis is accomplished by deep skin scraping in 12 or more affected sites. The skin must be scraped in numerous sites at the very edges of the advancing lesions. This is because the mites are usually at the head of the tunnels beneath the skin. Occasionally, Sarcoptes mites can be very difficult to retrieve and the animal is treated based on the characteristic lesions and the response to therapy.

As can be seen in the image below, Sarcoptes mites spend their entire life on or in the skin. The male and female copulate on the skin surface and the male soon dies off. The female then burrows into the upper layer of skin (stratum corneum) and begins forming a honey-comb of tunnels. As she tunnels along eggs are laid that fill the tunnels. Adult mites feed on the serum (clear component of blood) that oozes into the tunnels from the surrounding irritated tissue. When the female mite completes her egg laying mission she dies at the end of the tunnel. The eggs soon hatch to form larvae and then molt to become nymphs. The larvae and nymphs also feed on serum and skin debris. When the nymph makes a final molt to become an adult they return to the skin surface where they mate and start the life-cycle over anew. Transmission from animal to animal is thought to be through direct contact. Dog and cats in close contact with an infected host are succeptible. Animals can also become infected from fomites e.g. infested pens and blankets, combs, brushes, collars and any upholstered surfaces. Young and poorly nourished animals are the most succeptible to infection.

The Pet

Sarcoptic mange is fairly easy to kill with dips (Amitraz), pour-on miticides (alcohol based Ivomec), or oral products (Milbemycin - Interceptor). The condition also may need to be treated with an antibiotic for the secondary bacterial infection and corticosteroids to decrease the intense itch and inflammation.

Adult Sarcoptic mange mites can live for 21 days in the environment without feeding. For that reason all brushes, combs, collars, bedding, carpeting and upholstered surfaces must be sprayed with an insecticide. Household flea treatment products effectively kill the adult mites. One or two thorough applications generally destroys adults in the environment.

Yes! Ever hear of the "Seven Year Itch"? That's another term for Sarcoptic Mange in humans. Like pets, humans have a particular variety of mites that can cause advanced " Sarcoptic mange". This is totally separate variety from the ones that cause "mange" in dogs and cats; however, if the variety of mange mite that affects dogs and cats gets on a human it can cause a nasty red welt just like a mosquito bite. Several of these bites can be rather troublesome. Since these varieties are not well adapted to humans, they do not produce the extensive tunnels and cause the advanced lesions and scabs over the skin surface. They just burrow in a short distance and die. This causes inflammation and the resulting welt.