Why is a cat losing hair? Get to know all about feline alopecia

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4 Key points on hair loss in cats: 

1

Signs

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The best way to detect alopecia is to actively look for it, as it may be very subtle at an early stage. From focal hair loss to large bald spots, alopecia in cats have various presentation.

2

Causes

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There are many different causes of alopecia in cats, both itchy (e.g., from parasites or allergies) and non-itchy (e.g., from ringworm, follicular parasites, endocrine diseases). Other causes of alopecia can include an injection reaction or sometimes be considered normal.

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What to do

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If you notice bald patches in your cat, with or without other symptoms, always seek veterinarian guidance for treatment.

4

Treatment

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Treatment should be aimed at the problem that is causing your cat to lose hair but also at repairing the integrity of the skin. 

If you have a feline companion, you can surely recognize shedding as a normal part of your cat’s life, especially during spring and autumn. However, if hair loss results in areas of bald skin, be it in a circumscribed area or all over your cat’s body, this means there may be a problem. As there are numerous reasons that can lead to hair loss, also known as alopecia, if you notice that your cat is losing hair, we recommend that you seek veterinarian advice.

How can you tell if your cat is losing hair?

If you notice that the look of your cat’s coat, which was previously lustrous and dense, now seems thin and sparse, your cat may have a problem causing the hair to fall excessively.

It can be categorized as:

Focal, if it is circumscribed and limited to one area of the body

Multifocal, if it is circumscribed and present in several areas

Or generalized if it affects a large area of the body.

How hair loss looks will depend on what is causing it, and it can change over time. For instance, a single focus of alopecia can progress to generalized hair loss if the underlying cause is not identified and treated.

The best way to detect alopecia is to actively look for it, as it may be very subtle at an early stage. A good time to do this would be when your cat sits on your lap for a cuddle or during your regular grooming routine.

If your cat is losing hair excessively, depending on what’s causing it, you may find other skin lesions as well, including:

Thin skin

Dry skin and dandruff (scaling)

Oily skin (seborrhea)

Tiny bumps (papules)

Small, crusted lesions (miliary dermatitis)

Raw skin (excoriations, erosions or ulcers) and wounds

Red skin

As hair loss can be caused by self-trauma due to itchy skin, monitoring your cat’s behavior is also very important, as you may be able to notice restlessness, scratching, rubbing against objects and overgrooming.

Cats of the Sphynx breed are naturally hairless. In these cats, hair loss is caused by a genetic mutation that results in hair growth abnormalities, meaning that hairlessness is perfectly normal and not a reason for concern.

What causes cats to lose hair?

There are two main reasons why alopecia can occur, which are:

Self-trauma, with the cat actively pulling the hair from the skin follicles or breaking it by grooming, scratching or rubbing against objects. When this happens, it’s usually a sign that the cat is itchy and is trying to find ways to relieve the itchiness.

Problems at the level of the hair follicle or that affect hair growth.

Go to the next picture for illustration of the disorder(s)

Dr Chiara Noli, Hair loss and crust on a cat's head linked to pruritus

Dr Mariane Silva, Hair loss linked to excessive licking with redness

Itchy conditions with cat scratching and licking

Where more generalised, cats may have a greasy, oily coat and an unpleasant odour coming from the skin.

In more localised areas, cats may present with blackheads, well known in feline acne where forming on the cat’s chin, usually followed by inflammation and possibly infection. Another greasy localised presentation is stud tail, a condition in which excess sebum accumulates at the base of the tail, that can be associated with hair loss, blackheads, skin redness and sometimes secondary infection.

External parasites: There are a number of parasites that can cause itchy skin in cats, the most common being fleas. Lice and mites, such as Cheyletiella (walking dandruff), Otodectes (cat ear mites), and Notoedres (cat scabies), can also cause itchiness of variable intensity, leading to scratching and self-inflicted hair loss.

Allergies: Allergic conditions are common in cats, and allergic cats can suffer
from more than one type of allergy. Allergies are usually categorized as environmental, also known as atopic dermatitis, food allergies, or as flea allergy dermatitis, but other insects’ stings, such as wasps and bees, can also trigger an allergic response.

Non itchy conditions leading to hair loss

Just like our own hair, cats’ hair emerges from the skin from hair follicles, and problems at the follicular level can lead to hair loss.

Go to the next picture for illustration of the disorder(s) 

Dr Chiara Noli, Ringworm lesion on a cat's head. Localised hair loss with redness 

Dr Chiara Noli, Hair loss and redness in cat's head linked to demodicosis

Hair loss due to hair follicle inflammation
There are several causes that can lead to inflammation and injury of the hair follicle, causing the hair to fall. These include the most common causes:

Ringworm: Also known as dermatophytosis, ringworm is actually a fungal infection and not a parasitic disease. It typically presents as circular areas of hair loss with scales or crusts, which may or may not be itchy. Dermatophytosis is contagious to other animals and people as well.

Follicular parasites: in some cats, usually those that suffer from underlying health conditions, Demodex, a parasite that lives in the hair follicle or on the surface of the skin, can overgrow and lead to hair loss. This is known as feline demodicosis.

Immune-mediated disorders: Immune-mediated disorders, such as pemphigus foliaceus, for example, result from the immune system not being able to recognize normal cells as normal and attacking them as if they were foreign, which can lead to
alopecia.

Skin trauma: Burns and severe abrasive lesions can lead to scarring and permanent hair loss.

Alopecia due to metabolic or systemic disease

There are a number of health conditions not directly related to the skin that can lead to hair loss in cats, such as:

Endocrine diseases: Hyperthyroidism is a common endocrine (hormonal) disorder that causes hormonal changes that can lead to hair loss and other skin alterations in cats, most often thin, dry, flaky skin and a dull coat.

Tumor-related: This type of alopecia is a skin manifestation of systemic neoplastic conditions (cancer). Paraneoplastic alopecia is related to the tumor’s indirect effects on the body rather than its local growth or invasiveness. It is mostly linked to tumors in the pancreas, bile duct or liver, as well as thymomas.

Alopecia due to injection reaction
Mild cutaneous reactions at the injection site can be seen in cats upon vaccination. Reactions can include hair loss, along with irritation, swelling, erythema and discomfort.

Go to the next picture for illustration of the disorder(s) 

Dr Chiara Noli, Bald abdomen in a cat linked to compulsory licking

Psychogenic alopecia
Stress, anxiety and painful health conditions, such as osteoarthritis, can lead to excessive grooming and consequent hair loss.

Even though it is self-inflicted, psychogenic alopecia is usually not due to pruritus; however, itchy skin may be involved either at the onset or later as a consequence of secondary lesions or infection.

Anagen and telogen effluvium
Anagen and telogen effluvium are rare causes of alopecia in cats and refer to hair loss in the growth and resting stages of the hair cycle, respectively.

Stress often triggers these, for example, due to an underlying health condition, chemotherapy, or surgical intervention.

Hair loss between ear and eyes. It is fairly normal in cats, more visible in cats with dark fur

Photo from Dr Marina Gatellet, Mild hair loss on the ear pinna of a cat

Alopecia due to feline preauricular and pinnal alopecia
Feline preauricular alopecia is thinning of the hair between the ears and eyes and is quite normal, and common, in any cat. Pinnal alopecia, common in Siamese cats, develops on the outside of the ear pinnae. No treatment is indicated for either; preauricular alopecia is a normal finding in cats, and cats with pinnal alopecia typically regrow hair within several months.

What can you do to help your cat?

If you notice your cat’s hair is falling out, resulting in bald patches of skin or an overall thinner coat, you should schedule an appointment with your veterinarian.

As feline alopecia can have several underlying causes, reaching a diagnosis can be a challenging and lengthy process, and your veterinarian may need to conduct several tests or even refer your cat to a dermatology specialist.

However, this process is essential to reach the correct diagnosis and start appropriate, individually-tailored treatment.

Even though treatment is always aimed at what’s causing alopecia, there are some topical products that your veterinarian can recommend to alleviate some of your cat’s discomfort, such as shampoos, ointments and spot-ons.

Don’t hesitate to reach out to your veterinarian if you have any concerns, and make sure you have all the in-fur-mation you need to provide your feline friend with the best care!