Canine Hair Loss Causes

There are many possible causes for canine hair loss, medically known as alopecia. From genetics to allergies, causes can be as simple as fleas or as complex as a psychiatric disorder. It is best to take your dog to a veterinarian for a definite diagnosis. To determine the cause of your dog's alopecia, the veterinarian may do a microscopic exam of your dog's hair, skin scrapings, a fungal culture and a skin biopsy. Treatment will depend upon the cause of the dog's hair loss.

  1. Dermatitis

    • Dermatitis, which causes skin irritation and can lead to hair loss, is the result of your dog having an allergic reaction to some substance. Common causes of dermatitis in dogs are antibiotics, metals, rubber, wool, plastics, chemicals, dyes, cleaning products, poison ivy, fleas or food. Another type, acral lick dermatitis, isn't from an allergic reaction, but a psychological disorder. The dog licks obsessively because of anxiety, boredom or stress. This type of dermatitis can also lead to alopecia.

    Mites

    • Parasites can also cause hair loss in dogs. While fleas can lead to dermatitis, mites can cause a condition known as manage that leads to alopecia. There are three types of mites that cause mange in dogs: demodectic, sarcoptic and cheyletiella. Symptoms of mange, in addition to hair loss, include skin that is scaly, red, blistered and ulcerated, and the dog having intense itching.

    Ringworm

    • Ringworm is a fungal infection of the skin, not a worm. Puppies are more likely to contract ringworm than adult dogs, and dogs that are already affected by a skin condition or that have a suppressed immune system are more susceptible to infection. Ringworm lesions appear in circular areas of hair loss. The skin will appear scaly and inflamed. Many dogs have itching when infected with ringworm.

    Hormonal Imbalance

    • Hormonal imbalances caused by hypothyroidism, which occurs when the thyroid gland isn't functioning properly, can lead to hair loss, dry or brittle hair, bacterial and yeast infections, lethargy and obesity. Cushing's Disease, which is a hormonal imbalance that occurs when the adrenal gland isn't functioning properly, also leads to hair loss. Other symptoms include thinning hair, easy bruising, increased thirst and urination, and swelling in the abdomen.

    Hereditary Conditions

    • Dachshunds are predisposed to hair loss.

      Various hereditary conditions might cause hair loss in dogs. Acanthosis nigricans is an inherited condition seen in dachshunds. Black hair follicular is a rare hereditary disease that occurs often in bearded collies, basset hounds, beagles, dachshunds and pointers. Symptoms begin when puppies are younger than 6 weeks and include loss of dark or black hair. Mutant alopecia is a hereditary condition seen most often in Dobermans, dachshunds, Great Danes, Yorkshire terriers, whippets and greyhounds. With this condition, hair that is blue or fawn thins when the puppy is about 6 months old.