Hair loss in dogs

Updated 11/09/2023

Dogs shed - fact. But excessive hair loss in dogs, known as alopecia, may indicate that your pooch is a little under the weather. Here we’ll discuss the causes and symptoms to look out for, plus when it might be time to consider taking your pup to the vets.

What is hair loss in dogs?

Dog hair loss is not the same as shedding. During shedding season, dogs lose small amounts of fur daily in preparation for changing temperatures. However, uncomfortable-looking bald patches often combined with dry, red or inflamed skin are signs of hair loss in dogs. If your four-legged friend starts to become noticeably lacking in fur, especially if they seem uncomfortable, it’s time to take them to the vet to find out what’s going on.

Causes of hair loss in dogs

From allergic reactions and skin conditions to signs of infection or illness, let’s take a look at what causes hair loss in dogs. 

• Dog allergy hair loss may be triggered by environmental allergies like pollen and dust mites, as well as the ingredients in their dog food.
• The allergen that affects dogs in their diet is usually the protein within it. The troublesome protein source is one that the dog has been exposed to for some time (not a new food), so the most common allergies are to chicken, beef, and lamb, as these are the most common protein sources in commercial dog food. 
• Additionally, some dogs can have allergies to the carbohydrate in the food. Allergies to food can show by causing gastric upsets or skin conditions/alopecia in dogs. Some deficiencies, such as zinc deficiency, can also lead to hair loss, so supplements or a diet change may need to be considered if your vet diagnoses or suspects this.
• Hair loss in dogs may also be a sign your dog has an underlying hormonal disease, such as hypothyroidism - a condition where the body doesn’t produce enough thyroid hormone, affecting processes in the body including hair development at the root. This leads to the hair thinning in patches, usually symmetrically on the sides of the body.
• Cushing's disease, another underlying hormonal disease, may also be a potential cause. This is a condition whereby the body produces too much natural steroid. One effect of too much steroid in the body is hair loss. Hormonal conditions can lead to a disruption in the skin barrier and as a result of this, it's not uncommon to get secondary/accompanying infections such as bacterial or fungal infections. If your dog experiences frequent infections, consider talking to your vet about looking for an underlying cause. 
• Damage to hair follicles can happen in a number of ways, such as sun damage, physical injury, or poor living conditions - the result of which can be leaving your pup prone to nasty bacterial or yeast infections and fungal skin infections like ringworm. 
• Reactions to flea bites can cause Flea Allergy Dermatitis, and alopecia can also occur from other parasites like mites, lice, spider bites, and insect stings.
• Your pooch may suffer from post-clipping alopecia after surgery.
• Friction from a collar or repeated movements may trigger hair loss in dogs.
• Rarely, rabies vaccines can cause alopecia in dogs. 
• OAPs, or Old Age Pooches, may rest for long periods of time on areas like the elbows and hips, causing pressure sores which can lead to hair loss. 
• If your furry friend is losing hair but not itching, this could be a sign of the autoimmune disorder ‘alopecia areata’. 
• Certain breeds such as Dobermans, Bernese Mountain Dogs, and Chihuahuas sometimes inherit hair-loss genes.

Symptoms

Pet sitters and pet parents should keep an eye out for the following symptoms of hair loss in dogs:

• Red, inflamed skin
• Dry, itchy skin
• Dandruff 
• Small red spots or sores on the skin
• Bald spots of missing fur
• Overall thinning of the coat 
• A symmetrical pattern of hair loss
• Licking the fur 
• Excessive scratching

What to do if your dog is losing its hair

If your dog is losing unusual amounts of hair, take them to the vet. Although dog hair loss is quite common, it may be a sign of an underlying health condition. Your vet will be able to make a diagnosis, and then recommend the best course of treatment. 

Diagnosis

The vet will likely be able to diagnose the reason for your dog’s hair loss from a quick physical examination, but blood tests, skin scrapes, smears, or biopsies may also be done. The position or pattern of hair loss, including symptoms accompanying hair loss, will help your vet diagnose the cause and therefore direct treatment. Depending on the diagnosis, your vet will give you advice on how to make your pooch more comfortable. 

Dog hair loss treatment

Although your best pal may not be looking like the fluff bag they once were (not to mention they could be feeling downright uncomfortable), hair loss in dogs is not life-threatening. Your vet will advise you on how to treat the cause of hair loss, from prescribing medication like antibiotics, antihistamines, antifungals, and steroids to recommending a change in diet, possibly also considering vitamin A, vitamin E, and omega-3 supplements.

But if alopecia is in your dog’s genes, unfortunately, there is no “cure”. Neither are allergies able to be cured, but they are able to be managed with a proper treatment plan to suit your dog. To make your pooch more comfortable, avoid washing your dog frequently but use a moisturizing shampoo or a medical one prescribed by your vet when you do. Your vet will likely guide you on if and when (and what with) you should bathe your pup. Use a flea treatment all year round and be gentle when brushing your furry friend, taking the opportunity to check out the condition of your dog's skin and coat. But remember, while these remedies can help alleviate discomfort, always follow the advice of your vet first. 

Related article: Can dogs get hairballs? How to prevent hairballs in your dog

Meet our veterinary expert, Lily

This article has been checked by veterinarian Lily Richards BSc (Hons) BVSc MRCVS. Lily qualified from Liverpool University in 2011 and spent 5 years as a veterinarian working in mixed animal practice. As Lily’s passion for exotics and exploring more complicated small animal medical cases developed, she stepped into small animal-only practice. By 2018 Lily was leading a busy branch of a large hospital practice with a fantastic team, enjoying working on both surgical and medical cases. Since falling poorly in 2021 Lily has found a new passion in medical writing. Sharing medical knowledge and writing for the public is a particular passion.