Alopecia (hair loss) in dogs

Hair loss in dogs, known as alopecia, is a symptom rather than a disease itself. While some shedding is completely normal, patchy hair loss, thinning fur or bald areas can be a sign of an underlying health problem that needs veterinary attention.

Alopecia can be caused by a wide range of conditions, including parasites, infections, allergies, hormonal disorders and inherited skin conditions. Some causes are mild and easily treated, while others require ongoing management.

Because diagnosing the underlying cause often involves veterinary examinations, skin tests, blood tests or long-term treatment, dog insurance can help cover the cost of investigations and care.

What is alopecia in dogs?

Alopecia is when a dog loses some or all of its hair in places where their coat would normally grow. It can affect just one small area or larger parts of the body.

Unlike normal moulting, alopecia causes noticeable thinning, bald patches or changes to the coat. It happens when the normal hair growth cycle is interrupted, the hair follicles are damaged, or an underlying health condition stops the hair growing back properly.

What causes alopecia in dogs?

There are many possible causes of alopecia in dogs, including:

Parasites and infections

• Parasites such as fleas, mites and demodex mange (a skin condition caused by microscopic Demodex mites)
• Ringworm and other fungal infections
• Bacterial skin infections

Allergies and skin conditions

• Food allergies
• Environmental allergies
• Excessive licking, scratching or chewing caused by itching, pain or stress

Hormonal and immune conditions

• Hormonal conditions such as hypothyroidism or Cushing's disease
• Autoimmune diseases
• Alopecia X (the "X" means the causes isn’t exactly known, although some veterinary dermatologists suspect it’s to do with a dog’s genetics or a hormone imbalance)

Injury and scarring

• Trauma, wounds or scarring that damage hair follicles
  In many cases, the hair loss itself isn’t the problem. Instead, it’s a symptom of another condition affecting the skin, immune system or hair follicles.
• Damaged hair follicles

Which breeds are more prone to alopecia?

Alopecia can affect any dog breed, but some breeds are more likely to develop certain types of hair loss.

Breeds commonly associated with inherited or breed-related alopecia include:

• Pomeranians
• Chow Chows
• Alaskan Malamutes
• Samoyeds
• Keeshonds
• Miniature Poodles
• Dachshunds
• Dobermanns
• Bulldogs

Some breeds are also more prone to conditions that can lead to alopecia, such as allergies, hormonal disorders or demodectic mange.

What are the different types of alopecia in dogs?

Vets may classify alopecia in different ways. This can include localised, multifocal, symmetrical, congenital (or hereditary), and acquired alopecia.

Localised alopecia

Hair loss affects a single area or patch of skin. This can occur with conditions such as ringworm or localised demodex infestations.

Multifocal alopecia 

Several separate patches of hair loss appear across the body. This pattern can be caused by infections, parasites, or conditions where the dog's immune system mistakenly attacks healthy skin or hair follicles.

Symmetrical alopecia

Hair loss develops evenly on both sides of the body. Hormonal conditions and Alopecia X commonly produce this pattern.

Congenital or hereditary alopecia

Some dogs are born with abnormal hair follicles or develop hair loss because of inherited conditions.

Acquired alopecia

This develops later in life and is the most common form of alopecia seen in dogs. It may be inflammatory (caused by infection or skin disease) or non-inflammatory (often linked to hormonal or genetic causes).

Symptoms of alopecia in dogs

Symptoms vary depending on the underlying cause but may include:

• Patchy hair loss
• Thinning fur
• Bald areas
• Dry, flaky or scaly skin
• Red or inflamed skin
• Itching, scratching or licking
• Crusts or scabs
• Darkening of the skin
• Pimples or skin infections
• Changes in coat quality
• Some dogs are very itchy, while others lose hair without showing any signs of discomfort.

What should you do if your dog is losing hair?

If you notice your dog developing bald patches, thinning fur or areas where their coat seems unusually sparse, it's a good idea to book an appointment with your vet. Hair loss is often a symptom of an underlying condition rather than a condition itself, so finding the cause is the first step towards effective treatment.

Before your appointment, it can be helpful to note when you first noticed the hair loss, whether your dog seems itchy or uncomfortable, and if there have been any recent changes to their diet, environment or routine.

Avoid using human skin treatments or home remedies unless advised by your vet, as some products can irritate your dog's skin or make the problem worse.

When should you see a vet?

If your dog develops bald patches or thinning fur, it's a good idea to book a vet appointment, especially if they're also scratching, licking or chewing at their skin, or if it looks red, sore or infected. You should also speak to your vet if the hair loss continues to spread, your dog seems uncomfortable or distressed, or you notice other changes, such as increased thirst, weight changes or changes in their behaviour.

Getting your dog checked early can help identify the underlying cause and give them the best chance of successful treatment.

At what age can dogs develop alopecia?

Alopecia can develop at almost any age, depending on what's causing it. Some inherited forms of alopecia may be noticeable when a dog is still young, while hair loss linked to conditions such as demodectic mange is often seen in puppies and young dogs. 
Other causes, including hormonal conditions like hypothyroidism or Cushing's disease, are more commonly diagnosed in middle-aged or older dogs. 

Because alopecia is a symptom with many possible causes, there isn't a specific age when dogs are most likely to experience it. If you notice unusual hair loss at any stage of your dog's life, it's worth having it checked by a vet.

How is alopecia in dogs treated?

How alopecia is treated depends on what’s causing the hair loss.

Diagnosing the cause

Managing alopecia starts with identifying and treating the underlying cause. Diagnosis could involve skin scrapes, blood tests, allergy testing, etc.

While some causes of alopecia can be resolved completely, others may require ongoing management to keep symptoms under control.

Treatment options

Once your vet has diagnosed what's causing the hair loss, they can recommend the most appropriate treatment plan, which may include parasite control, medication, allergy management, dietary changes or treatment for an underlying hormonal condition.

Treatment options could include:

• Flea and mite treatments
• Antifungal medication for ringworm
• Antibiotics for bacterial skin infections
• Anti-inflammatory medication
• Allergy management plans
• Hormone replacement therapy
• Treatment for underlying immune-mediated disease
• Specialised dermatology care for complex cases

In many cases, hair regrows once the underlying condition is controlled, although some hereditary forms of alopecia may be permanent.

Managing alopecia long term

Regular grooming and checking your dog's skin and coat can help you spot changes early and monitor their progress during treatment. 

Following your vet's advice and attending any recommended follow-up appointments can help give your dog the best chance of maintaining healthy skin and fur.

Does pet insurance cover alopecia in dogs?

Pet insurance may help cover the cost of diagnosing and treating conditions that cause alopecia, including consultations, diagnostic tests, medication and ongoing treatment, depending on your policy and the underlying condition.

As alopecia is often a symptom of another health problem, cover will depend on the diagnosis and whether the condition is new or pre-existing. Always check your policy documents for details of what’s included.