Demodectic mange is known by several common names including red mange, pustular mange, and puppy mange. The disease is caused by a cigar-shaped mite that lives in the hair follicles of the skin. The presence of this mite in the hair follicle causes local inflammation and disruption of the hair growth cycle. Alopecia (hair loss) develops and the typical signs of the disease become clinically apparent.
Two distinct forms of the disease can occur. Localized demodectic mange occurs commonly in puppies and is characterized by small circular areas of hair loss on the face and front legs. Generalized demodectic mange can develop in older dogs that do not recover from the localized form of the disease. Hair loss is generalized and the skin may become secondarily infected with bacteria.
Transmission of demodectic mange is thought to occur in young puppies during the first two to three days of life, after exposure to an affected female, carrier females, or other infected dogs. Experimental transmission is difficult to achieve in older puppies. Elimination of carrier females as brood females may be helpful to control this disease in certain kennel situations.
Therapy is directed at control of the mite, control of bacterial infections, and removal of stress conditions from the dog. Research at the present time is exploring the possibility that clinical disease results from allergic reactions induced in the skin by the demodectic mange mite. Many cases will show spontaneous improvement regardless of the therapy used.
Sarcoptic Mange
Sarcoptic mange or canine scabies causes intense itching in the dog. This mange mite burrows into the skin of dogs and causes intense inflammation of the skin. Sarcoptic mange is extremely contagious from dog to dog and is spread by direct contact between the animals.
The parasite is a transitory parasite on humans, causing a red itchy rash, similar to chigger bites. The disease in humans will resolve when the dog is effectively treated.
Clinical signs include intense scratching and hair loss on the elbows, hocks, and ear margins. In severe cases, the entire body may be involved. Diagnosis is made from clinical signs and demonstration of the mite in skin scrapings. This disease can be cured with proper therapy consisting of weekly dips in lime sulfur solutions, chlorinated hydrocarbons, or organophosphates. Therapy of all infected or exposed dogs should occur at the same time in order to effectively control the disease.