Skin allergies, hot spots, scabies, and other skin conditions can make your dog’s life an itchy misery. Skin conditions often take considerable time to treat and heal. Additionally, treatment of these skin conditions is often complicated by secondary skin infections.
Allergies are some of the most common skin conditions that affect dogs. Dogs may develop skin rather than respiratory symptoms, due to food, nasal or contact allergies. Allergic skin reactions are one of the most common causes of itchy skin in dogs.
Cheyletiella (Walking Dandruff)
Cheyletiella, or “walking dandruff,” is an infestation of the fur by tiny white mites. Three varieties of cheyletiella exist:
- Cheyletiella blakei usually target cats.
- Cheyletiellaparasitovorax favors rabbits.
- Cheyletiellayasguri generally infects dogs.
All three species of cheyletiella can be transmitted to dogs and humans. Cheyletiella typically causes itchy skin rashes in humans. In dogs, the mites cause:
- “walking dandruff”
- scaling (dandruff)
- skin crusting
- skin inflammation.
“Walking dandruff” refers to a heavy infestation of cheyletiella, in which the tiny white mites appear to be moving flakes of dandruff in the dog’s fur.
Treatment for cheyletiella includes anti-parasitic dips and shampoos, usually over the period of a month. Ivermectin injections are also used but are a controversial treatment that should never be used to treat Beagles, Shelties, Collies or Collie mixes.
Demodex, or demodectic mange, is a mite infestation that usually affects young puppies but sometimes affects older dogs. Symptoms include:
- baldness beginning around the face
- pustules due to bacterial infections.
- Demodex often recurs and is seen most often in short-haired breeds. Demodectic mange is treated using one or a combination of three methods. All of these forms of treatment are effective, curing about eighty percent of the cases.
- A medicated dip, known as Mitaban® is often the first course of treatment. Dogs often require a number of Mitaban dips before a Demodex infection is resolved. Mitaban is the only approved treatment for Demodex.
- In some cases, ivermectin injections, given daily until the infection is resolved, may be administered. Some dogs, particularly Collies and Shelties, are super-sensitive to ivermectin.
- An oral medication is known as Inceptor® (milbemycin), sold as a monthly heartworm preventive, may be used daily for up to three months to treat the Demodex infection.
Fleas are the most common cause of skin conditions in dogs. Fast moving parasites, fleas are difficult to detect and can infest dogs blankets and surroundings. Black debris in the dog’s coat suggests a flea infestation, as does scratching and biting.
Hot spots, also known as summer sores and wet eczema, are skin conditions caused by bacterial infection. These bacteria usually live on the dog’s skin, but some event has triggered a sudden population growth that overwhelms the dog’s natural defenses.
Any dog can develop hot spots. Certain factors increase the risk of hot spots, including:
- ear infections
- flea infestations
- heavy coats
- tangled hair/mats
- warm, humid environment
- excessive licking/chewing.
Hot spots usually develop as circular patches of baldness. The skin in these bald spots may become red and irritated and develop a foul-smelling pus due to infection. Hot spots are painfully itchy and can lead to licking, scratching and biting that often worsens the infection.
While hot spots usually develop on the legs, feet, rump or flanks, they can develop anywhere on the dog. To treat hot spots the hair is trimmed to reveal the sore. Topical antibiotics or cortisone medications are used to combat infection and relieve itching.
For successful treatment of hot spots, the cause of the infection must be found. Regular grooming helps prevent tangled mats that encourage hot spots. If allergies are the cause of hot spots, identifying and avoiding contact with the allergen is essential.
If behavioral problems such as excessive licking or chewing contribute to hot spots, a good deal of time and effort is required to determine why the dog engages in the behavior and to change behavior patterns.
Ticks are large, eight-legged, blood-sucking parasites most common in warm, wet environments. In the United States, ticks can spread Lyme disease and Rocky Mountain Spotted Fever, two zoonotic diseases that can cause serious health conditions in both dogs and humans.
Scabies is a mite that affects dogs and foxes. Unlike cheyletiella, scabies mites burrow into the skin and are incredibly difficult to detect even with multiple skin scrapings.
In most cases, scabies initially causes itching in the ears and elbows, before spreading to other areas of the body. Scabies causes skin lesions that mimic skin allergies. Dry, crusted lesions develop, hair loss is common and because the mites actually burrow into the skin, the infection may be so painful that the dog engages in self-injurious biting in an attempt to relieve the pain.
Because scabies is so difficult to diagnose, many cases are misdiagnosed as atopic dermatitis and cortisone is prescribed. Unfortunately, cortisone stimulates the scabies mites reproduction cycle, making the infection even worse. To avoid this most veterinarian will treat the dog for scabies before beginning treatment for dermatitis.
Scabies is usually treated with the topical parasiticide Revolution® (selamectin) monthly for several months. Revolution also treats infestations of fleas, ticks and ear mites and prevents heartworm infection.
As scabies mites can also infect a dog’s bedding, treating or replacing his bedding is necessary. Many veterinarians will also recommend supplementing the dog’s diet with essential fatty acids.