Alopecia, or hair loss in dogs,
is caused by diseases and conditions that affect the health of
your dog’s coat, from the skin down to the hair follicles.
Diagnosing the direct cause of hair loss is key for
veterinarians to treat alopecia. In fact, there are over fifty
known conditions that can cause hair loss in dogs, so many vets
have their work cut out for them.
The most common causes of alopecia fall into three categories:
1. Parasitic Causes of Alopecia
Infection, allergy or reaction to parasites can bring on hair
loss in dogs. Common parasitic causes of alopecia include:
Mites - the Demodex mite is a
microscopic mite that lives in the hair follicles.
Exposure to this mite, combined with a weak immune system,
causes red mange, also known
as puppy mange, which can induce hair loss. A Sarcoptes mite
infection or exposure to other less common mites can also
cause different types of mange and hair loss.
Fleas - dogs that are sensitive
to flea bites or who have flea
allergy dermatitis can experience hair loss due to excess
itching and irritation.
2. Allergic Causes of Alopecia
Allergic reactions have been known to affect dog hair in
certain cases. Allergies that have been linked to alopecia
Food Allergies - some food
allergies will cause itching, redness, and hair loss.
Atopy - allergies to particles
in the air that dogs inhale such as dust, mold, or pollen can
- Medicine - allergic reactions to medications or injections
can cause hair loss.
- In some cases, allergies to or issues with the fit of a
collar or bedding can cause Alopecia
3. Endocrine and Hormonal Causes of Alopecia
Dog’s with endocrine disorders and hormonal imbalances can
experience hair loss. Such disease include:
Cushing’s Disease - this
condition stems an increase in corticosteroids caused by
overproduction in the adrenal glands, or an imbalance due to
prolonged therapy using corticosteroids.
Hypothyroidism - the most
common hormonal disease that affects dogs, hypothyroidism’s
lower production of hormones can cause hair loss.
Other Causes of Alopecia
Other causes of alopecia include bacterial and fungal
infections that affect the skin or hair follicles. Ringworms,
or the onset of kerion infection from ringworms, are the most
common fungal cause that can lead to alopecia.
Nursing or pregnant dogs can develop a type of alopecia called
“blowing their coat,” which develops from nutritional
deficiency or stress.
Stress, trauma, nutritional deficiencies, and hereditary causes
can also lead to hair loss. Some breeds have a genetic
predisposition to certain types of alopecia; they include
doberman pinschers, boxers, bulldogs, airedale terriers, pomeranians, chow chows, miniature poodles, samoyeds, and siberian huskies.
Pet owners who see signs of hair loss should contact their vet.
Some of the underlying causes of alopecia may be symptoms of
severe illness that could be treated with early intervention.
The Symptoms of Alopecia in Dogs
Alopecia is an abnormal type of hair loss caused by a disease
or condition. Unlike seasonal shedding, this type of hair loss
can appear in patterns, bald patches, and over specific areas
of the head, body, legs, and tail. The symptoms and severity of
alopecia will vary from case to case depending on the
underlying cause of the hair loss.
The most common symptoms of alopecia include:
Noticeable hair loss
While some dogs develop thinning or brittle hair with age,
alopecia affects the coat due to an underlying cause that
requires treatment. Pet owners may notice bald patches or
larger areas of complete or partial hair loss on their dogs.
The hair loss may be gradual or sudden. In some cases, the hair
may grow back partially and then fall out again. The hair loss
may look symmetrical or random, or appear in completely bald
patches. Hair loss can affect one specific area of the body,
such as the base of the tail or the haunches, or appear all
While some dogs only exhibit hair loss with alopecia, others
may also experience changes in the skin. Check for scaly skin,
changes in skin color, inflammation, bites, redness, lesions,
and hot spots. You may also
find changes in the skin’s texture, such as thickened, oily, or
thinner skin. Darkened skin is a symptom of one type of
alopecia known as Alopecia X, or black skin disease.
Some dogs display symptoms such as scratching, biting, licking,
or chewing their skin with alopecia. Dog’s with hormonal or
endocrine disorders may also experience lethargy and other
signs of illness.
Signs of alopecia can be connected to more serious illnesses,
such as Cushing’s disease.
If you notice hair loss on your pet’s coat, make sure to visit
your veterinarian to diagnose the underlying cause.