Scabies – or sarcoptic mange - is a highly infectious skin condition caused by the parasitic mite sarcoptes scabei.
In scabies, the female mites burrow "tunnels" into the skin of their host to lay eggs. These eggs hatch after three weeks and then develop into adult mites that live off of the animal's skin (keratine) particles, and cause irritation. Ears, eyelids and limbs – especially the elbows – are usually the first skin areas to be affected. From here the infection spreads across the body. The predominant feature of sarcoptic mange is a permanent, unceasing itch. Through the course of the infection the animal's coat thins out, and assumes a moth-eaten appearance. The skin beneath the animal's fur is crusted and thickened. Pyogenic inflammation (pyoderma) may develop as a result of injury incurred through scratching. While sarcoptic mange (scabies) is primarily a skin disease, in severe cases it can severely affect the overall health of the animal and cause fever, pain, and lethargy.
Transmission of sarcoptic mange occurs through direct contact with an infected animal or an animal corpse, i.e. a dead fox or badger. Alternatively, baskets, blankets or grooming instruments may act as transmission vectors, as mites can remain infectious in outside their host environments for as long as three weeks. While cats, cattle, weasels and foxes are susceptible to sarcoptic mange, dogs are the most commonly affected. The parasite is not visible to the bare eye.
Diagnosis of sarcoptes is challenging. As they dwell deep in the skin, actual scrapes penetrating as deep as the subcutis are necessary in order to perform a scan for mites in the of the skin using a microscope. Furthermore, negative samples are not always definitive in ruling out sarcoptic mange. Sarcoptes are susceptible to a variety of antiparasitic drugs and washing-lotions. Skin conditions caused by sarcoptes infestations may be much harder to relieve and require prolonged administration of antibiotics and anti-inflammatory drugs. Blankets, toys and resting areas have to be washed or disinfected thoroughly to prevent re-infection. Additionally, in order for treatment to be effective, all animals in contact with a potentially infected dog have to be treated concurrently.
To provide reliable protection against skin-parasites, dogs and cats should receive topical treatment with quality spot-ons, or other products, as often as every three months. Products are easy to apply and may be purchased in pet shops or veterinary clinics without prescription. Flea colars show insufficient effects and should be avoided.