Hair Loss in Cats (Alopecia / Overgrooming)

What Causes Hair Loss in Cats?

Common underlying causes of hair loss in cats include allergic skin disease, infections, parasites and other conditions affecting the skin or hair follicle. Hair loss (alopecia) can result from a range of different disease processes and is most commonly associated with overgrooming rather than a primary hair disorder. In many cats, hair loss is self-induced through overgrooming, even when this behaviour is not observed by owners, making it an important but often overlooked cause.

Hair loss is best understood by considering the underlying causes and contributing factors:

While hair loss itself is often a noticeable sign, it is typically a symptom rather than a primary diagnosis. Identifying the underlying cause is essential for effective management.

Signs Associated with Hair Loss in Cats

Hair loss in cats can present in a variety of ways and is often less obvious than in dogs, particularly in early or mild cases.

Common signs include:

• Thinning of the coat or areas of hair loss, particularly on the abdomen, legs or flanks
• Short, broken or “barbered” hairs, indicating overgrooming
• Smooth or normal-looking skin beneath areas of hair loss
• Changes in coat quality or texture

Some cats may also show:

• Subtle or intermittent overgrooming behaviour
• Skin lesions, including scabs, plaques or areas of inflammation
• Signs associated with underlying allergy or infection

Because grooming is a normal behaviour in cats, excessive grooming may be overlooked or mistaken as normal, and hair loss may be the first visible sign. The pattern and distribution of hair loss often provide important clues to the underlying cause, particularly when changes are recurrent or progressive.

Why Hair Loss Can Become Ongoing or Recurrent

Hair loss may persist or recur when the underlying cause is not identified or adequately managed, or when secondary factors continue to affect the skin and hair growth cycle. In some cases, repeated inflammation, infection or overgrooming can disrupt the normal hair growth cycle, preventing regrowth.

This can lead to a cycle where:

• An underlying condition affects the skin or hair follicle
• Skin irritation or inflammation develops
• The cat responds by overgrooming or licking
• Hair is lost due to repeated grooming and disruption of the hair coat
• The underlying condition remains, preventing normal regrowth
• Secondary factors such as infection or ongoing irritation further delay recovery

Over time, this may result in:

• Persistent areas of alopecia
• Delayed or incomplete coat regrowth
• Secondary skin changes, including irritation or infection

In some cats, repeated inflammation or grooming may disrupt the normal hair growth cycle, making regrowth slower or less complete even once the underlying cause is controlled.

How We Diagnose the Causes of Hair Loss in Cats

Hair loss in cats can have many different causes, so a systematic and structured approach is required to identify the underlying condition and guide targeted treatment. This includes determining whether hair loss is due to overgrooming (self-induced alopecia) or a primary disorder affecting the skin or hair follicle. Where referral is recommended, your cat’s assessment begins with a dermatology consultation, where our clinician reviews their history and previous treatments, and performs a thorough examination to assess the type, distribution and progression of hair loss and associated skin changes.

From here, our clinicians tailor a targeted diagnostic approach to your cat’s individual presentation.

A tailored diagnostic approach may include:

• Cytology and Fine-Needle Aspirates – used to identify infection or inflammation that may be contributing to hair loss. 
• Hormone Disorder Testing – used in selected cases where an endocrine condition is suspected as an underlying cause. 
• Elimination Diet Trials – used where a cutaneous adverse food reaction is suspected. 
• Airborne Environmental Allergy Testing – used in selected cases where environmental allergy is suspected as an underlying cause of recurrent skin disease and infection, helping guide allergen-specific immunotherapy (ASIT). 
• Biopsy and Dermatopathology – recommended in selected cases to assess the hair follicle and support diagnosis of more complex or unusual conditions. 
• Skin scrapings and parasite testing – used to rule out mites and other parasitic causes
• Assessment of flea exposure and response to effective flea control – particularly where flea allergy dermatitis is suspected

Each step helps build a complete clinical picture, ensuring that treatment is based on an accurate diagnosis.

How Hair Loss in Cats Is Managed

Management depends on the underlying cause, the severity and duration of hair loss, and your cat’s individual needs. Effective treatment focuses on addressing the primary condition, supporting skin health and allowing normal hair regrowth.

Depending on the diagnosis, treatment may include:

• Treatment of underlying allergy or skin disease
• Management of bacterial or yeast infections where present
• Treatment of hormonal (endocrine) conditions in selected cases
• Parasite control, where relevant
• Dietary management where a food-related trigger is identified
• Medications to reduce inflammation and associated discomfort where present
• Strategies to reduce overgrooming and support normal grooming behaviour
• Supportive therapies to improve skin and coat health

For many cats, hair regrowth occurs once the underlying condition is controlled, although this may take time depending on the hair growth cycle, severity and duration of disease. The goal is not simply to improve coat appearance, but to restore skin health, normal grooming behaviour and coat quality, and achieve long-term stability.

Related Conditions

Cat Allergies

Skin Infections in Cats

Parasites in Cats

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