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canine health problems
German Shepard with bald spots

There are many reasons why your dog may suffer from hair loss, also known as alopecia over the course of their lifetime. Some of these reasons are fairly benign while others can be concerning. We’ve broken down many of the most common reasons hair loss can happen to your dog, and the signs it’s time to call the veterinarian.

12 common reasons why your dog might be losing hair

1. Shedding

Shedding is one of the most common causes of hair loss in dogs. This is because most dogs that have fur shed at least a little. Double coated dogs may grow out a thicker coat in the winter and shed it in the spring. Interestingly, dogs who spend much of their time indoors may shed fairly consistently all year round because their coat thickness fluctuates less.

2. Allergies

Both food and environmental allergies (pollen, mold, etc.) can cause dogs to lose hair. If you see bald patches on your dog, it may be a sign that something is irritating your dog’s skin and the hair is falling out as a result. Dogs also may bite or lick itchy areas, especially in places near their elbows, thighs, paws, and rear ends, and this can lead to hair loss too.

3. Skin infections

Both bacterial infections and fungal infections can cause hair to fall out. Like with allergies, your dog may also be excessively itching or licking at the infected area which can cause more hair loss. Another reason you don’t want your dog to itch or lick at the area is that this can spread the infection further – which can result in additional hair loss.

👉 Ringworm and yeast infections are very common skin infections in dogs.

4. Fleas

Fleas are a very annoying pest and can spread around your home (and to the rest of your family) so using a flea preventative is really important. Dogs are allergic to flea bites which can lead to intense scratching. If your dog has fleas, is severely itchy, and has hair loss on the rump/tail areas, then there is a good chance your dog has a flea allergy.

In order to help your dog quickly, schedule an appointment with your local vet so that anti-itch medication and an oral flea/tick prevention can be prescribed to treat the itch and kill the fleas quickly.

5. Mites (Mange)

There are two different types of skin mites that dogs can have. Demodex, also called demodectic mange, is a mite that normally lives in the haired skin of healthy dogs.  However, sometimes puppies can have larger numbers of demodex in their hair follicles which leads to patchy areas of hair loss that usually are not itchy. Some puppies with demodex can develop secondary bacterial skin infections which can be itchy.

The other type of skin mite that dogs can have is scabies, aka sarcoptic mange.  These mites are highly contagious and cause intense itching, hair loss, and crusty lesions on the ears, elbows, and hocks. Sarcoptic mange is rare, but if your dog is very itchy then it’s important to seek medical care as soon as possible for your dog. Dogs that have scabies can spread this parasite to people and other pets in the household.

To confirm a mange diagnosis, the vet will take a skin scraping which means scraping the areas of hair loss gently with a scalpel blade. The sample will then be examined under the microscope to see if skin mites are present.

6. Genetics

Some dogs are predisposed to hair loss because of their genetics. Conditions like color dilution alopecia (CDA) can cause patches of thinning hair and hair loss as well as itchy skin (leading to more hair loss). Other conditions like albinism and protein deficiency can also lead to hair loss.

7. Hormonal changes

Hair loss can also be due to endocrine disorders, like hypothyroidism and Cushing’s Disease.  Hypothyroidism is caused by insufficient production of thyroid hormones. As a result, dogs that are hypothyroid have symmetrical areas of hair loss on the body, unexplained weight gain, and recurring skin and ear infections.

Dogs with Cushing’s disease have an overproduction or exposure to glucocorticoids (steroids) which leads to symmetrical areas of hair loss on the body, excessive thirst, urination, and panting. A blood test can be done to diagnose hypothyroidism or Cushing’s disease. Both of these conditions are treatable with medication.

8. Sunburn

If your dog is having too much fun in the sun, they can get sunburn just like humans. Sunburn can occur on the bridge of the nose, ear tips, around the lips, and on the abdomen and inner legs where there is less fur. Severe enough sunburn can lead to hair loss.

To prevent sunburn (and subsequent skin cancer) use dog-appropriate sun protection such as doggles (dog goggles) and doggie sunscreen when heading outside for an extended period.

9. Aggressively licking themselves

There are many reasons your dog may aggressively lick themselves ranging from allergies and infections to boredom. If your dog is aggressively licking itself you’ll need to do some detective work (along with your vet) to determine the root cause and provide appropriate treatment.

10. Cancer

If your dog is losing hair, it may be a symptom of cancer somewhere in your dog’s body. While the most obvious conclusion would be skin cancer, this isn’t always the case. Other cancers like thyroid cancer and other cancers in the endocrine system can also cause hair loss in dogs.

11. Seasonal flank alopecia

This medical condition occurs when your dog loses some hair seasonally but there’s no evidence of another skin disease. Seasonal flank alopecia often starts in young adulthood and continues annually. The exact cause of this condition is unknown but it’s believed to be genetic, especially in boxers who are most prone to the condition.

12. Contact with a skin-irritating substance

Chemicals including those found in some cancer treatments can irritate a dog’s skin leading to hair loss. If your dog has come in contact with a chemical substance, call your vet or the ASPCA’s poison control line for further instructions. They can help you get the substance out of your dog’s hair and off their skin safely.

When should you see a vet about your dog’s hair loss? 

  • Your dog is itching. Your vet can help you play detective to find the underlying cause of the itching. From fleas to allergies and even mange, there are so many things that can make a dog feel itchy. It’s important to determine the cause so you can treat the issue properly.
  • You smell a bad odor. A bad odor may be the sign of an infection so it’s important to see the vet before the infection spreads or makes your dog sicker. If your dog has a skin infection, then the vet will prescribe oral and/or topical medication to treat the infection.
  • Your dog’s skin is irritated or infected. A bad odor isn’t the only sign of irritation or infection. If you see redness, blisters, skin, a rash, or any other changes in your dog’s skin they should see the doctor.
  • You see behavior changes in your dog. Behavior changes in your dog can be a sign of an underlying medical issue or that your pup is in pain. Describe the changes in your dog’s behavior or take a video if it’s something you can record so your vet can see what’s going on and help you get to the bottom of it. You may also want to keep notes of what you’re seeing (and when) to help you explain to the vet all of the changes.
  • Your dog has lesions. Take your dog to the vet if you see lesions on your dog’s skin. The vet may need to do a diagnostic test (such as a fungal culture, tape prep, skin scraping, or biopsy) to determine the cause of the lesions.

Treatments for hair loss in dogs

Before you can start treating your dog’s hair loss, it’s important that you understand why your dog is losing hair. This will help ensure you are providing the most effective treatment. While many of these treatments are safe, treating the root cause of why your dog’s hair is falling out in the first place will help make sure you’re actually helping Fido.

Shampoos that help with skin issues and allergies

There are a variety of shampoos that are available over the counter to help ease or treat your pup’s symptoms that are causing their hair loss. From dry itchy skin to allergies, there are products for every need.

If your dog is suffering from itchy skin, here are the best shampoos to try — we also have an entire list of our favorite antifungal shampoos. However, only use an antifungal shampoo on your dog if your dog has been diagnosed with a yeast skin infection and your vet has recommended an antifungal shampoo for treatment.

Doggie supplements

Supplements with omega-3 fatty acids are known to improve dog coats and may even help prevent hair loss. You can also use some of these supplements to treat dandruff. We’ve rounded up some of our favorite omega-3 supplements and salmon oils to try. While there are many supplements on the market for doggies, our favorites include a liquid Omega Oil from Native Pet and easy-to-eat Omega Chews from Premium Care.

Some supplements are designed to be delicious on their own, but others may need to be given with food to either mask the taste or ensure your pup takes them. For supplements, you may be directed to add a pump or spoonful to your pet’s meals. For gel caps, you can cover them in peanut butter or cream cheese so your pup will find taking their supplement fun and exciting!

👉 Our full guide has 8 vet-approved tips on how to give your dog a pill!

Hypoallergenic food and treats

If the cause of your pup’s hair loss is food sensitivities or allergies, your vet may prescribe a hypoallergenic diet. These diets are free of the ingredients that your dog is allergic to. But, to find the right food for your pet you’ll want to read labels carefully to check for hidden allergens.

👉 Check out our favorite hypoallergenic foods here. 

When you make changes to your dog’s diet, don’t forget about their treats. Ensure that anything your dog is eating (food treats, supplements, and even medications) is free of allergens so you aren’t accidentally making your dog sick.

Preventing bald spots on your pup

Regularly groom your dog — Not only will this help brush out hair as it sheds, it’s also a good opportunity to check for bald spots or places where the hair is thinning. Shedding can be seasonal so make sure to keep up with the grooming when you notice your dog is shedding.

👉 Remember that regular grooming might be quite frequent for breeds that are prone to matting, like poodles and doodle breeds.

Feed your pet a high-quality diet — Food allergies can be one of the reasons your dog is losing hair so a high-quality diet free from known allergens can help keep your pup from losing hair. A high-quality diet should also include sources of omega-3 fatty acids like fish oil to keep your dog’s skin and coat looking and feeling their best.

Avoid allergy triggers — Like food allergens, environmental allergens can irritate your dog’s skin and cause hair loss. Avoiding these allergens and using allergy medications as well as bathing your dog after exposure to allergens will help keep your dog from itching, licking, and losing their hair.

Stay on top of flea and tick preventatives — Not only can fleas and ticks make your dog sick, but their bites can also be itchy or painful causing your pup to itch and lick themselves excessively. This can lead to bald spots and hair loss. By using preventatives as directed by your vet you can avoid this entirely.

Remember, healing your dog’s skin and regrowing hair won’t happen overnight. Chat with your vet about when you can expect to see improvement and don’t hesitate to check in if things aren’t improving or you’re seeing changes or new symptoms.