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Hair Loss in Dogs

There could be many reasons why your dog might experience hair loss. These reasons range from allergies and seasonal shedding to more severe reasons like alopecia. Today, our Astoria vets what causes patches of hair loss in dogs.

What causes hair loss in dogs?

Hair loss in dogs can be caused by a variety of factors, including allergies, parasites, and skin infections. Allergies, whether from food or environmental factors, can lead to excessive itching and scratching which can result in hair loss. Parasites such as fleas, ticks, and mites can also cause irritation and hair loss if left untreated.

Additionally, bacterial or fungal skin infections can cause inflammation and damage to the hair follicles, resulting in hair loss in affected areas. It is important to consult with a veterinarian to determine the underlying cause of your dog's hair loss and develop an appropriate treatment plan. 

We’ll go into some more detail about these various causes of hair loss below.

Seasonal Shedding

Brushing your dog twice a week can aid in the removal and reduction of unwanted hair. Dogs shed their fur when their hairs become worn or damaged, or when the weather warms up. For example, huskies and Labradors have thick winter undercoats that they shed in the spring. Seasonal shedding is frequently reduced if you live in a temperate climate.


Parasites, such as fleas, ticks, and mites, can cause a dog to lose hair by irritating the skin and causing excessive scratching or biting. These parasites can also transmit diseases that affect the dog's overall health, leading to hair loss as a secondary symptom. Regular grooming and preventative measures such as flea and tick medication can help protect dogs from these parasites and reduce the risk of hair loss.

Bacterial & Fungal Infections

Dogs, like humans, can develop bacterial or fungal skin diseases. Pyoderma is a bacterial skin infection that is most noticeable when the skin is red and pus-filled. Candida infections, also known as yeast infections, occur when the yeast that is always present on a dog's skin overgrows. Ringworm, also known as tinea, is a fungal infection that causes dry skin and damaged hair in circular areas.


Mange is a term that refers to itchy skin conditions caused by mites. Mites are microscopic organisms that live on the surface of the skin or in hair follicles. Scabies mites, for example, are highly contagious to humans and other dogs. If you find mites or fleas on your dog, consult your veterinarian about an antiparasitic treatment.


Dogs, like humans, can develop allergies, with itchy skin and hair loss being the most common symptoms. The most common allergies in dogs are to irritants such as pollen, mold, dust mites, flea allergies, and food allergies. However, dietary allergies can only be detected after at least eight weeks of food trials.

Old Age

Old age can cause a dog to experience hair loss. Their skin becomes less elastic and their hair follicles may not function as efficiently. Additionally, hormonal changes in older dogs can also contribute to hair thinning or bald patches.

Other Medical Conditions

Excessive shedding can be caused by stress, poor diet, pregnancy, nursing, or any underlying medical condition. A dog who is losing hair should see a veterinarian, even if his illness is usually treatable with a simple diet or medication change. They will recommend dog hair loss therapy based on your pet's other health needs.


Alopecia is a relatively common condition. It refers to either thinning hair or areas of hair loss (bald spots). This is distinct from shedding, which is a natural part of your dog's hair development cycle and varies by breed.

Symptoms and Causes of Alopecia

Depending on the cause of alopecia, symptoms can include:

  • Mild to severe scratching
  • Skin that is red, inflamed, thickened, oozing, bleeding, malodorous, or pigmented
  • Skin with papules

Likewise, there are numerous causes of alopecia, which include:

  • Ectoparasites and bug bites
  • Skin infections and allergies
  • Genetic predispositions
  • Autoimmune disorders Endocrine diseases
  • Environmental causes
  • Nutritional causes

Breeds Susceptible to Alopecia

Mexican Hairless, Chinese Crested, Bulldogs, Dobermans, Yorkshire Terriers, Dachshunds, Greyhounds, Siberian Huskies, Pomeranians, Golden and Labrador Retrievers, and West Highland White Terriers are among the dog breeds predisposed to alopecia.

Further, any breed with poor husbandry, especially puppies, is at risk for mange.

How to Keep Your Dog's Coat Healthy

To keep your dog's coat healthy, it is important to regularly brush and groom them to remove any tangles or mats. Additionally, providing a balanced diet rich in essential fatty acids can help promote healthy skin and coat. 

Regular baths with a gentle dog shampoo suitable for their specific coat type can also help maintain a healthy shine and prevent skin issues. Lastly, ensuring your dog gets enough exercise and stays hydrated can contribute to overall coat health.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding people or pets. Always follow your doctor's advice regarding asthma or other allergy symptoms.

If you're concerned about your dog's hair loss, contact our Astoria vets today for professional advice.

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At Steinway Court Veterinarian, we are always accepting new patients. Our vets are dedicated to keeping pets healthy and happy in our Astoria clinic. Contact us today to book your first appointment.

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