Why is My Dog Losing Hair?

Hair loss, also known as alopecia, is a common concern for dog owners. While some shedding is normal, excessive or patchy hair loss may signal an underlying health problem. Understanding the causes of hair loss in dogs is crucial for addressing the issue and ensuring your furry companion remains happy and healthy. In this blog, we’ll explore why your dog might be losing hair and what you can do about it.

Normal Shedding vs. Hair Loss

Shedding is a natural process where dogs lose old or damaged hair to make way for new growth. The amount of shedding depends on the breed, season, and individual factors. For instance, double-coated breeds like Labradors and Huskies shed heavily during seasonal changes, while non-shedding breeds like Poodles lose minimal hair.

However, if your dog is shedding excessively, developing bald patches, or their coat appears thin and dull, this is not normal shedding. These signs may indicate an underlying health issue that requires veterinary attention.

Common Causes of Hair Loss in Dogs

1. Parasites

Parasites like fleas, mites, and ticks are among the most common causes of hair loss in dogs. These pests irritate the skin, causing itching, scratching, and biting, which can lead to hair loss.

• Fleas: Some dogs develop flea allergy dermatitis (FAD), a hypersensitive reaction to flea saliva, resulting in widespread hair loss and severe itching.
• Mites: Mange, caused by microscopic mites, leads to patchy hair loss and severe irritation. There are 2 main types: 
  • Sarcoptic mange (Sarcoptes scabiei): Highly contagious to other animals and humans, it often causes intense itching, red, crusty skin, and secondary infections. 
  • Demodectic mange (Demodex canis): Not contagious, it typically affects young dogs with immature immune systems or adults with underlying health issues. Mild cases may resolve on their own, but severe cases require veterinary care.
• Ticks: Heavy infestations or localised skin reactions can cause irritation and hair loss.

What to do: Year-round parasite prevention is essential. If you suspect an infestation, consult your vet for appropriate treatment. 

2. Allergies

Dogs can suffer from allergies to food, environmental factors, or contact allergens. Allergic reactions often manifest as itching, redness, and hair loss.

• Food allergies: Ingredients like beef, chicken, or dairy can cause reactions in some dogs, leading to skin problems and hair loss.
• Environmental allergies: Pollen, dust mites, and grasses can cause seasonal or year-round itching and shedding.
• Contact allergies: Shampoos, cleaning agents, or certain fabrics may irritate your dog’s skin, resulting in localised hair loss.

What to do: Identify and eliminate the allergen if possible. Your vet may recommend allergy testing or a dietary trial to pinpoint the cause. Treatments may include antihistamines, medicated shampoos, or other therapies.

3. Skin Infections

Skin infections, whether bacterial or fungal, can lead to hair loss. These may occur as primary conditions or secondary to scratching or skin injuries.

• Bacterial infections: Pyoderma often causes red, inflamed areas and patchy hair loss.
• Fungal infections: Ringworm is a contagious fungal infection that causes circular patches of hair loss with scaly or crusty skin.

What to do: Veterinary treatment is necessary and may include topical or oral medications. Ringworm is a zoonotic disease, so take precautions to protect yourself and others.

4. Hormonal Imbalances

Hormonal disorders can interfere with your dog’s hair growth cycle, leading to thinning fur or bald spots.

• Hypothyroidism: An underactive thyroid gland slows metabolism, causing hair thinning, lethargy, and weight gain.
• Cushing’s disease: Excess cortisol production can result in hair loss, a pot-bellied appearance, and increased thirst and urination.
• Oestrogen imbalances: Hormonal changes after spaying or neutering may contribute to hair loss in some dogs.

What to do: A vet can diagnose hormonal issues through blood tests and recommend appropriate treatments, such as hormone replacement therapy or medication. Early diagnosis can help prevent progression.

5. Stress or Anxiety

Stress or anxiety can cause hair loss in dogs, often due to excessive licking, chewing, or scratching.

Common triggers include:

• Moving house
• New family members or pets
• Changes in routine
• Separation anxiety

What to do: Identify and address the source of stress. Behavioural training, environmental enrichment, pheromone diffusers, or anti-anxiety aids may help your dog feel more secure.

6. Nutritional Deficiencies

A poor diet lacking essential nutrients can result in a dull, brittle coat and eventual hair loss. Omega-3 fatty acids, zinc, and biotin are particularly important for skin and coat health.

What to do: Feed your dog a high-quality, nutritionally complete diet. If you suspect a deficiency, consult your vet for advice on dietary adjustments or supplements.

7. Genetics

Certain breeds are predisposed to hair loss due to genetic traits or conditions.

• Chinese Crested and Mexican Hairless: Naturally hairless breeds.
• Dobermans: Can suffer from colour dilution alopecia, which causes thinning hair and bald patches.

What to do: While genetic hair loss cannot be cured, regular grooming and skin care can keep your dog comfortable.

8. Autoimmune Diseases

Autoimmune diseases like alopecia areata or lupus cause the immune system to attack the body’s own hair follicles or skin, resulting in patchy hair loss.

What to do: These conditions often require long-term management with immunosuppressive therapies or other veterinary treatments.

When to See the Vet

Seek veterinary attention if:

• Hair loss is accompanied by redness, swelling, or sores.
• Your dog is excessively itching, licking, or chewing.
• Bald patches appear suddenly or worsen over time.
• Your dog seems lethargic, unwell, or in pain.
• The condition is spreading to humans or other pets.

Early diagnosis and treatment can prevent complications and improve your dog’s quality of life.

How to Prevent Hair Loss in Dogs

Prevention is always better than cure. Here are some tips:

• Regular grooming: Brush your dog’s coat to remove loose hair and distribute natural oils.
• Parasite control: Use vet-recommended flea, tick, and mite preventatives.
• Balanced diet: Provide high-quality, nutritious food tailored to your dog’s needs.
• Bathing: Use gentle, dog-specific shampoos and avoid over-bathing.
• Routine vet visits: Regular check-ups can catch issues early.

Final Thoughts

Hair loss in dogs can stem from a variety of causes, from simple grooming issues to complex medical conditions. Identifying the underlying reason and seeking appropriate treatment can help your dog regain a healthy, shiny coat. A vet can provide the expert guidance needed to determine the cause and recommend effective solutions. With the right care, your dog will soon be back to their happy, furry self!