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 pet parents is knowing when hair loss is normal shedding and when it's a symptom that warrants veterinary attention.
In clinical practice, cats with hair loss are a regular sight, 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 clues to what's going on.[1]
This guide covers the common causes of hair loss in cats, what to watch for, and when a vet visit tends to be worthwhile. Key claims are supported by veterinary sources listed at the end.
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 isn't 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, this is often a sign something is wrong.
Common Causes of Hair Loss in Cats
1. Fleas and Flea Allergy Dermatitis
Flea allergy dermatitis (FAD) is one of the most common causes of hair loss in cats in the UK.[1][2] 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 tends to be 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 and flea bites, 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 can include moving house, new pets, changes in routine, or lack of environmental enrichment. This is a diagnosis of exclusion. Other causes (fleas, allergies, pain) tend to need to be ruled out first.[1]
3. Allergies
Cats can develop allergies to environmental triggers (pollen, dust mites, mould), food ingredients, or flea saliva. Allergic cats often 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 usually 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 eight to twelve week elimination diet using a novel protein or hydrolysed diet is the standard approach for diagnosis, and this is usually guided by your vet.
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 isn't 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.[3] Diagnosis requires fungal culture or PCR testing, and treatment is prescribed by your vet.
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 how to treat 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 tends to be worth investigating with your vet. For related signs of discomfort, see our guide on arched back in cats.
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 is prescribed by your vet.
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 is prescribed by your vet.
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 is 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 can provide useful clues:
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| Pattern | Likely cause |
|---|---|
| Symmetrical hair loss (belly, flanks, inner thighs) | 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 issues |
| Localised to one area | Pain, trauma, or infection |
When Should Pet Parents See the Vet?
We'd suggest contacting 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
If pain, urinary signs, or straining in the litter tray are also present, our guide on cat UTI symptoms, signs and causes covers urinary red flags.
How Is Hair Loss Diagnosed?
Your vet will typically 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:[1]
- 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 function, 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
How Hair Loss Is Treated
Treatment depends entirely on the underlying cause, and in almost every case the right next step is a conversation with your vet, who can prescribe or recommend treatments appropriate to your cat.
Broad approaches typically include:
- Flea allergy dermatitis: year-round flea treatment for all pets in the household, environmental flea control, and any skin treatment your vet prescribes
- Allergies: allergen avoidance where possible, with medication or other options guided by your vet
- Ringworm: antifungal treatment prescribed by your vet, plus thorough environmental decontamination
- Over-grooming: addressing underlying stress, environmental enrichment, pheromone products, and vet guidance where needed
- Pain: treatment of the underlying condition with your vet
- Hormonal disorders: treatment prescribed and monitored by your vet
- Skin infections: antimicrobial treatment prescribed by your vet
Most cases of hair loss respond well once the cause is identified, though some conditions (such as allergies and stress-related over-grooming) can require long-term management.
Can Hair Loss in Cats Be Prevented?
- Year-round flea treatment: helpful for all cats, including 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
Litter Sense doesn't detect skin conditions. What it does is monitor your cat's urine daily and change colour when pH shifts or blood is present, which may help pet parents flag urinary changes worth speaking to a vet about.
Hair loss and skin changes can sometimes go hand-in-hand with urinary signs, particularly where pain conditions like cystitis cause both over-grooming and discomfort in the litter tray. In that scenario, Litter Sense may help pet parents notice urinary changes earlier. For most skin problems though, a vet examination is the reliable route to a diagnosis. To learn more about Litter Sense, read our complete guide on how Litter Sense works.
Frequently Asked Questions
Why is my cat losing hair in patches?
Patchy hair loss is often 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. We'd suggest booking a vet appointment for diagnosis.[1]
Is it normal for cats to have bald spots above their eyes?
Yes. There's 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, speaking with your vet is a good idea.
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 tends to be key to improvement.
Will my cat's fur grow back?
In most cases, yes, once the underlying cause is addressed. 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 keep up to date with flea treatment and reduce obvious stressors, most causes of hair loss benefit from veterinary diagnosis. 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.[3] If your cat is diagnosed with ringworm, washing your hands after handling them and avoiding sharing bedding tends to help. If you develop skin lesions, we'd suggest speaking with your GP.
Important: This article is general educational information about hair loss and bald patches in cats and does not constitute veterinary advice for any individual cat. If your cat is unwell, showing new or worsening symptoms, or you have specific concerns about their skin, coat or health, please consult a registered veterinary surgeon who can examine your cat and provide personalised guidance.
Dr Bolu's Health Series Complete
← Previous: Cat Flea Bites on Humans
Read posts in the series:
- Cat UTI Symptoms, Signs & When to See a Vet
- Cat Flea Bites on Humans
- Hair Loss & Bald Patches (you're here)
References
- Merck Veterinary Manual. Hair Loss (Alopecia) in Cats. Available at: https://www.merckvetmanual.com/cat-owners/skin-disorders-of-cats/hair-loss-alopecia-in-cats
- PDSA. Flea Allergic Dermatitis in Cats. Available at: https://www.pdsa.org.uk/pet-help-and-advice/pet-health-hub/conditions/flea-allergy-in-cats
- Blue Cross UK. Ringworm in cats and dogs. Available at: https://www.bluecross.org.uk/advice/cat/health-and-injuries/ringworm-in-cats-and-dogs
- International Cat Care. Skin conditions in cats. Available at: https://icatcare.org/articles
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Featured Product Your Cat Can't Tell You They're Sick Litter Sense litter changes colour when it detects early signs of illness in your cat's urine — giving you a warning before symptoms appear. See How Litter Sense Works → |