5 Common Causes of Hair Loss in Dogs

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PetMD Editorial
Published: April 24, 2015

What’s Causing the Dog Hair Loss?

Seeing a dog lose his or her hair can be disconcerting to witness. However, what’s most important when dealing with alopecia, as it is referred to medically, is identifying the underlying cause of the hair loss in order to devise an appropriate treatment plan. Here are five common culprits of hair loss in dogs that should be discussed with your veterinarian. 

1. Allergies

Allergies are a frequent cause of hair loss in dogs. This may due to environmental triggers such as pollen, molds and dust mites, or due to parasitic triggers like fleas or mites. Food allergies are another possible cause of hair loss. Typical symptoms of an adverse allergic reaction include itchiness resulting in excess scratching, biting, and, of course, hair loss. In the case of flea allergies, it is recommended that dogs take flea preventatives as a way to minimize threats of a full-blown flea infestation. 

2. Infection or Infestation

An infestation with parasites such as fleas, ticks, and mites (scabies, mange) is another source canine alopecia. Along with hair loss around the ears, eyes, abdomen, and chest, signs your dog may have mites or fleas/ticks include inflammation, itching and redness. Bacterial or fungal infections, such as in the case of ringworm (which is actually a fungus), can also be attributed to hair loss in dogs. Symptoms of ringworm include circular or irregular hair loss, inflammation, and infected crusts.

3. Cushing's Disease

Hyperadrenocorticism, also known as Cushing's disease, is a condition caused by the prolonged exposure of the body’s tissue to excessive levels of the hormone cortisol. Symptoms of Cushing’s disease include hair loss, darkening of the skin, and the development of a pot-bellied abdomen. Cushing’s disease commonly occurs in middle-aged to senior dogs, though it can also affect dogs that overuse corticosteroid drugs. 

4. Genetics

There are some breeds of dog that are more genetically prone to baldness than others. First there are the hairless dogs that have been bred for the attribute such as the Chinese Crested, Mexican Hairless (Xolo), and American Hairless Terrier. Other dog breeds, such as the Doberman Pinscher, Dachshund, Chihuahua, Italian Greyhound and Whippet, sometimes suffer from patchy or pattern baldness on the outer ear, chest, back, thigh, or lower neck.

Image: Valeri Potapova / Shutterstock

5. Pressure Sores

Pressure sores, also called bedsores or decubital ulcers, are localized injuries where the dog’s elbows or other bony pressure points (hips, hocks, etc.) come into contact with hard surfaces regularly. This constant pressure and friction causes the skin to callus, lose hair and sometimes crack and bleed. Pressure sores are more common older dogs, especially large or heavy breeds.