It's normal for your canine companion to shed hair -- sometimes lots of it. What isn't routine is for that shedding to result in noticeable bald spots on your dog.
Why do dogs sometimes lose too much hair? Are certain breeds more prone to hair loss? Find out what causes bald spots in dogs and what you can do to keep your pet's coat in top form.
Bald Spots in Dogs: Common Causes and Treatments
There are lots of reasons dogs may lose hair (also called alopecia), from infection to irritation caused by parasites. A few of the more common reasons include:
Allergies are a frequent trigger for hair loss in dogs. Like people, dogs can have an allergic reaction to foods, environmental triggers such as pollen, or to parasites like fleas or mites.
Flea bites are behind most dog allergies, however. Along with hair loss from licking and biting the irritated areas, signs of flea allergies include itching and redness. For a particularly allergic dog, it may take as little as one flea bite to start an allergic reaction that lingers for days.
While any dog can have allergies, some are more prone to them than others. Treating your dog's allergies may include topical or internal medication, allergy shots, a change in diet, and avoiding the allergen.
Hair loss in dogs may also be caused by hyperadrenocorticism, or Cushing's disease, a condition caused by the overproduction of the hormone cortisol. Medication and sometimes surgery is available to treat Cushing’s disease, also known as Cushing's syndrome.
Cushing's disease is more common in dogs 6 years or older. Other signs of Cushing's disease include eating, drinking, and urinating more, panting, as well as having a pot-bellied appearance. Take your dog to the vet if you notice any of these signs.
There are some "hairless" dogs like Chinese crested and Mexican hairless, but there are some dogs are more prone to baldness than others. Bald spots on the outer ear, chest, belly, thighs, or lower neck may appear in greyhounds, whippets, Chihuahuas, dachshunds, and Italian greyhounds, usually after their first year.
Most owners learn to live with this, as treatment options are limited. Always make sure your vet has ruled out other causes of hair loss.
Infection or Infestation (Ringworm, Mites, Bacteria)
Ringworm fungus, pests like mange mites, and bacteria can all lead to infections that may ultimately cause bald spots on your dog.
Along with hair loss around the ears, eyes, mouth, and elsewhere, signs your dog may have mites include oily skin, thickened skin, itching, and inflammation. Symptoms of ringworm -- a contagious infection of the hair and skin that includes circular or irregular hair loss, inflammation, and infected crusts.
Although small ringworm lesions may clear up spontaneously, it is contagious and should be treated. Ringworm is treated with topical antifungal medications. In severe cases, oral antifungal medications may be necessary. Treating mites may require topical or oral medications, and antibiotics for secondary bacterial infections.
Older or heavy dogs can be prone to pressure sores where their elbows or other bony parts of the body come in regular contact with hard surfaces. Over time, the constant pressure tends to thicken the skin, the hair falls out, and calluses form.
If calluses crack, bleed, or get infected, treatment may include moisturizers, antibiotics, or use of bracing. You can prevent pressure sores and calluses by providing your pooch with cushioned bedding.
Insect bites and stings, medications, plants, chemicals, even shampoos can cause some dogs to develop a rash or hives, which can result in bald spots.
Allergic rashes usually appear within minutes to hours of exposure, and other symptoms can include listlessness, fever, lack of appetite, and vomiting. Always talk to your vet immediately if your dog develops hives as emergency treatment may be needed.
Other Causes of Bald Spots in Dogs
- Foreign body reaction. Glass, thorns, even a dog’s own coarse hair can all cause inflammation and bald spots if they lodge in your dog's skin. Along with hair loss, signs of irritation by a foreign body include swelling and licking the area repeatedly -- for example between the toes. Treatment may require lancing under local or general anesthesia to remove the irritant, and antibiotics if there's a secondary bacterial infection.
- Post-clipping alopecia. For some dogs, especially densely-coated breeds like the Alaskan malamute, Siberian husky, and keeshond, clipping -- for example in preparation for surgery -- can lead to persistent bald spots. A fairly common condition, there really isn't any treatment for post-clipping alopecia except patience while the hair grows back.
- Hypothyroidism.With hypothyroidism, the thyroid gland doesn’t make enough of a a hormone called thyroxine that controls metabolism. the result effects your dog's coat and can result in hair loss. It affects all breeds, but it is often found in golden retrievers, Doberman pinschers, Irish setters, dachshunds, boxers, and cocker spaniels. It usually happens in middle-aged dogs (ages 4 to 10) of medium to large breeds. Neutered males and spayed females also have a higher risk, but vets are unsure why.
When to See a Vet About Bald Spots in Dogs
See your vet if you're not sure what's causing your dog's bald spots or if those bald spots are also accompanied by:
- Bad odor
- Irritated or infected skin
- Changes in behavior
- Any skin lesions in other pets or people in the household