Cat Hair Loss & Bald Patches: Causes, Treatment & When to See a Vet

Hair loss in cats, known medically as alopecia, is one of those symptoms that can range from completely benign to a sign of serious underlying disease. Some cats lose hair in small patches that regrow on their own; others develop progressive balding that requires investigation and treatment. The challenge for owners is knowing when hair loss is normal shedding and when it's a symptom that warrants veterinary attention.

As a vet, I see cats with hair loss regularly, and the cause is rarely obvious at first glance. Fleas, allergies, stress, hormonal imbalances, infections, and even pain can all manifest as patchy fur loss. The location of the bald patches, the pattern of hair loss, and what the skin underneath looks like all provide crucial clues to what's going on.

This guide covers every common cause of hair loss in cats, what to watch for, and when you need to see your vet.

Is It Normal for Cats to Lose Hair?

Yes and no. Cats shed naturally, particularly in spring and autumn as they transition between seasonal coats. This is normal and expected. You'll see loose hair on furniture, clothing, and in the litter tray, but the cat's coat should remain full and even with no visible bald patches or thinning areas.

What's not normal is patchy hair loss, bald spots, excessive shedding in localised areas, or hair that comes out in clumps when you stroke your cat. If you can see the skin through the fur, or if your cat is scratching, licking, or biting at specific areas, that's a sign something is wrong.

Common Causes of Hair Loss in Cats

1. Fleas and Flea Allergy Dermatitis

Flea allergy dermatitis (FAD) is the most common cause of hair loss in cats in the UK. Cats with FAD are allergic to proteins in flea saliva, and even a single flea bite can trigger intense itching and over-grooming. The hair loss is typically concentrated along the back, base of the tail, and hind legs. You may see small scabs (miliary dermatitis) on the skin, excessive scratching, and restlessness. Some cats are such fastidious groomers that you never actually see the fleas only the hair loss and skin damage they cause. For more on fleas, read our guide on cat flea bites on humans.

2. Over-Grooming (Psychogenic Alopecia)

Stress-induced over-grooming is a common cause of symmetrical hair loss, particularly on the belly, inner thighs, and flanks. Affected cats lick themselves excessively, often when anxious or bored, and the constant grooming breaks the hair shaft and causes bald patches. The skin underneath is usually normal with no redness or scabs. Triggers include moving house, new pets, changes in routine, or lack of environmental enrichment. This is a diagnosis of exclusion other causes (fleas, allergies, pain) must be ruled out first.

3. Allergies

Cats can develop allergies to environmental triggers (pollen, dust mites, mould), food ingredients, or flea saliva. Allergic cats typically show intense itching, leading to over-grooming, scratching, and hair loss. The distribution depends on the allergen: flea allergy affects the back and tail base, food allergies often cause head and neck itching, and environmental allergies can be more generalised. Diagnosis requires elimination trials and sometimes allergy testing.

Food Allergies

Food allergies in cats most commonly develop in response to proteins like beef, fish, or dairy. Hair loss is usually accompanied by itching around the face, ears, and neck, and sometimes gastrointestinal signs like vomiting or diarrhoea. An 8-12 week elimination diet using a novel protein or hydrolysed diet is the gold standard for diagnosis. For more on digestive issues, see our guide on cat diarrhoea.

4. Ringworm (Dermatophytosis)

Ringworm is a fungal infection that causes circular patches of hair loss, often with scaly or crusty skin. Despite the name, it's not caused by a worm it's a fungus. Ringworm is more common in kittens, cats in multi-cat environments, and immunocompromised animals. It's also zoonotic, meaning it can spread to humans, causing ring-shaped, itchy rashes. Diagnosis requires fungal culture or PCR testing, and treatment involves topical and oral antifungal medication.

5. Skin Infections (Bacterial or Yeast)

Secondary bacterial or yeast infections can develop when the skin is damaged by scratching, over-grooming, or underlying disease. These infections cause redness, crusting, greasiness, odour, and patchy hair loss. They rarely occur in isolation and are usually a sign of an underlying problem (allergies, parasites, immune suppression) that needs addressing.

6. Hormonal Disorders

Hormonal imbalances, though rare in cats, can cause hair loss. Hyperthyroidism (overactive thyroid) is common in older cats and sometimes causes a poor coat quality and patchy fur loss alongside weight loss, increased appetite, and hyperactivity. Diabetes can also affect coat condition. For more on hyperthyroidism, read our guide on symptoms of hyperthyroidism in cats.

7. Pain

Cats often lick or groom excessively at painful areas, leading to localised hair loss. Arthritis, cystitis, anal gland problems, and dental pain can all trigger over-grooming. If hair loss is concentrated in one specific area and your cat seems uncomfortable, pain should be investigated. For more on recognising pain, see our guide on how to tell if your cat is in pain.

8. Ear Mites

Ear mites cause intense itching in and around the ears, leading to scratching and hair loss around the head, ears, and neck. Affected cats shake their heads frequently and may have dark, waxy discharge in the ear canals. Diagnosis is straightforward with an ear examination, and treatment involves prescription ear drops or spot-on treatments.

9. Mange (Demodex or Sarcoptes)

Mange mites are rare in cats but can cause patchy hair loss, particularly around the face, ears, and neck. Demodex is associated with immune suppression, while Sarcoptes (scabies) is intensely itchy and contagious. Diagnosis requires skin scrapes, and treatment involves prescription anti-parasitic medication.

10. Cancer

Rarely, skin tumours or internal cancers can cause hair loss. Mast cell tumours, squamous cell carcinoma, and lymphoma can all present with skin changes and patchy fur loss. This is more common in older cats and usually accompanied by other signs like lumps, weight loss, or lethargy.

Patterns of Hair Loss: What They Mean

The location and pattern of hair loss provide important diagnostic clues:

• Symmetrical hair loss (belly, flanks, inner thighs): Usually over-grooming, often stress-related or due to pain
• Hair loss along the back and base of tail: Flea allergy dermatitis
• Patchy circular bald spots: Ringworm
• Hair loss around the head, ears, and neck: Ear mites, food allergies, or mange
• Generalised thinning: Hormonal disorders, systemic illness, or nutritional deficiency
• Localised to one area: Pain, trauma, or infection

When Should I See the Vet?

Contact your vet if your cat:

• Has visible bald patches or thinning fur
• Is scratching, licking, or biting excessively
• Has red, inflamed, scabby, or crusty skin
• Has circular patches of hair loss
• Is losing weight, drinking more, or showing other symptoms alongside hair loss
• Has hair loss that's getting worse or spreading
• Seems uncomfortable or in pain

For more on recognising illness in cats, read our overview of cat illness symptoms and when to act.

How Is Hair Loss Diagnosed?

Your vet will start with a thorough history and physical examination. They'll look at the pattern of hair loss, examine the skin underneath, and check for fleas, scabs, redness, and other abnormalities. Depending on what they find, they may recommend:

• Flea comb: To check for fleas or flea dirt
• Skin scrapes: To look for mites
• Fungal culture or PCR: To test for ringworm
• Blood tests: To check for hormonal imbalances, kidney disease, or hyperthyroidism
• Allergy testing: Intradermal testing or blood tests for environmental allergens
• Elimination diet trial: To rule out food allergies
• Biopsy: If a tumour or unusual skin condition is suspected

Treatment for Cat Hair Loss

Treatment depends entirely on the underlying cause:

• Flea allergy dermatitis: Year-round flea treatment for all pets, environmental flea control, sometimes corticosteroids to reduce itching
• Allergies: Allergen avoidance where possible, antihistamines, corticosteroids, or immunotherapy (desensitisation injections)
• Ringworm: Topical antifungal shampoos or creams, oral antifungal medication (itraconazole or terbinafine), environmental decontamination
• Over-grooming: Address underlying stress, environmental enrichment, pheromone diffusers, sometimes anti-anxiety medication
• Pain: Pain relief, treatment of the underlying condition (dental work, arthritis medication, cystitis management)
• Hormonal disorders: Medication for hyperthyroidism or diabetes
• Skin infections: Antibiotics or antifungal medication

Most cases of hair loss respond well to treatment once the cause is identified, though some conditions (allergies, stress-related over-grooming) require long-term management.

Can I Prevent Hair Loss in Cats?

• Year-round flea treatment: Essential for all cats, even indoor-only cats
• Regular grooming: Helps you spot problems early
• Stress reduction: Maintain routine, provide hiding spots, vertical space, and enrichment
• Good nutrition: Feed a complete, balanced diet appropriate for your cat's life stage
• Monitor for changes: Check your cat's skin and coat weekly

How Litter Sense Can Help

While Litter Sense doesn't directly detect skin conditions, some systemic illnesses that cause hair loss (hyperthyroidism, kidney disease, diabetes) also affect the urinary system. Litter Sense monitors your cat's urine daily and can flag early changes that suggest underlying health problems, prompting you to seek veterinary care before symptoms become severe.

To learn more, read our complete guide on how Litter Sense works.

Frequently Asked Questions

Why is my cat losing hair in patches?

Patchy hair loss is usually caused by over-grooming (due to itching, stress, or pain), flea allergy dermatitis, ringworm, or allergies. The location and appearance of the bald patches, plus what the skin underneath looks like, help determine the cause. See your vet for diagnosis.

Is it normal for cats to have bald spots above their eyes?

Yes. There is a naturally sparse area of fur between the eyes and ears called preauricular alopecia. This is completely normal and not a sign of illness. However, if the bald area is spreading, red, scabby, or itchy, see your vet.

Can stress cause hair loss in cats?

Yes. Stress triggers over-grooming in many cats, leading to symmetrical hair loss on the belly, flanks, and inner thighs. The skin underneath is usually healthy with no redness or scabs. Identifying and reducing the stressor is key to treatment.

Will my cat's fur grow back?

In most cases, yes, once the underlying cause is treated. Hair regrowth can take several weeks to months depending on the severity and cause. Some conditions (severe scarring, certain tumours) may cause permanent hair loss.

Can I treat my cat's hair loss at home?

Not without knowing the cause. While you can ensure your cat is up to date with flea treatment and reduce obvious stressors, most causes of hair loss require veterinary diagnosis and treatment. Delaying can allow the condition to worsen.

Is ringworm contagious to humans?

Yes. Ringworm is a fungal infection that can spread from cats to humans, causing circular, itchy, red rashes. If your cat is diagnosed with ringworm, wash your hands after handling them, avoid sharing bedding, and see your GP if you develop skin lesions.