Hair loss is a common problem for canines.

Sometimes, hair loss is restricted to a relatively small area, but it can also occur all over your pet’s body. Likewise, hair loss can be the result of a relatively minor ailment, or it can be indicative of very serious health problems.

But no matter how much hair your dog is losing or what is causing the problem, you’ll want to address the issue promptly. Doing so will not only help eliminate unsightly bald patches, it’ll help ensure your dog remains healthy and happy too.

What Causes Excessive Hair Loss in Dogs?


A variety of common ectoparasites (those that attack the outside of your dog’s body) can cause dogs to lose hair. Fleas, demodectic mites, and sarcoptic mites are the most common parasites that cause canines to lose

Bacterial Infections

Several bacterial strains, including many types of Staphylococcus bacteria, can cause dogs to experience skin and coat problems. In addition to hair loss, these types of infections can cause redness, swelling, and itchiness.

Fungal Infections

A variety of fungi can cause dogs to suffer from hair loss. Ringworm is one of the most common fungi to cause hair loss, although yeast organisms can also cause a dog’s hair to fall out. In many cases, fungal infections cause hair to fall out in discrete locations, rather than in generalized fashion.


Allergies in dogs – including those caused by environmental triggers as well as those associated with food allergies – often lead to skin and coat problems. In some cases, the allergy itself may cause the hair to fall out, but in other cases, the hair loss is the result  of a dog’s scratching or chewing behaviors that the itchiness elicits.

Autoimmune Diseases

Autoimmune diseases occur when a dog’s immune system begins attacking his own body. There are a variety of different autoimmune diseases that affect dogs, and several of them – including, most notably, pemphigus foliaceus – can cause dogs to lose hair.

Cushing’s Disease

Cushing’s disease occurs when a dog’s adrenal glands produce too much cortisol. This causes a variety of different symptoms, including increased thirst, increased appetite, and the development of excessive body fat. Hair loss is also one of the symptoms commonly associated with the disease.


Hypothyroidism occurs when a dog’s thyroid gland fails to produce a sufficient level of thyroid hormones. Some of the most common signs of this condition include poor coat health and hair loss.

Congenital Diseases

A handful of breeds are susceptible to genetic conditions that cause hair loss. A few of the most commonly afflicted breeds include