MCV FAQ: Why Is My Cat Losing Fur? Understanding Feline Alopecia

It can be alarming to discover bald patches or thinning fur on your cat. While it might seem like a cosmetic issue at first, alopecia—the medical term for hair loss—can point to a variety of underlying issues, from something as simple as overgrooming to more complex medical conditions.

What Is Alopecia?

Alopecia is the partial or complete loss of hair in areas where it’s normally present. In cats, this can be localised (just a small area), symmetrical (on both sides of the body), or generalised across the body.

Importantly, alopecia is a symptom, not a diagnosis. The goal is always to understand why the hair loss is happening.

Differentiating whether the hair has been chewed off versus completely lost from the hair follicle is an important step in determining the underlying cause of baldness.

Common Causes of Feline Alopecia

Feline alopecia can result from a wide range of factors, and it often takes some detective work to find the root cause. Here are some of the more common culprits:

1. Overgrooming

Cats are fastidious groomers, but excessive licking—often triggered by stress, itchiness, or discomfort—can lead to bald spots. Interestingly, many cats do this in secret, so owners may not even realize it's happening.

2. Parasites

Fleas are one of the leading causes of hair loss in cats, particularly if your cat is allergic to flea saliva (flea allergy dermatitis). Mites and lice can also cause irritation that leads to overgrooming or scratching.

3. Allergies

Cats can develop allergies to food, pollen, dust, or other environmental triggers. Allergic skin disease is a common cause of symmetrical hair loss and itching.

4. Fungal Infections

Ringworm (which isn’t actually a worm) is a fungal infection that causes circular patches of hair loss, often with scaly or crusty skin. It’s contagious to other animals—and humans—so early diagnosis is key.

5. Endocrine and other Health Disorders

Hormonal imbalances, such as those seen with hyperthyroidism or Cushing’s disease, can cause symmetrical hair loss without itchiness. Unforutnately, rare forms of cancer can also cause certain baldness patterns These conditions are more common in older cats.

A typical hairloss pattern in a cat that is overgrooming. This is typically caused by either itch or stress (and sometimes both!).

How Is The Cause of Alopecia Diagnosed?

Since alopecia has many possible causes, we will likely start with a thorough history and physical exam, followed by some diagnostic tests, which may include:

• Skin scrapings or tape impressions to check for mites and other parasites

• Fungal cultures for ringworm

• Hypoallergenic food trials or referral to a veterinary dermatologist for allergy testing

• Blood tests to screen for hormonal diseases

• A skin biopsy and/or imaging (ultrasound/xrays) in more complex or unusual cases

  
  

As part of the investigation our vets will often microscopically examine samples from your cat's hair and skin. On the left is the hair follicle mite, Demodex, an uncommon but important cause of baldness in some cats.

What Treatments Are Available?

The treatment of alopecia depends entirely on the underlying cause. For example:

• Flea control can resolve flea-related alopecia.

• Allergy management may involve dietary changes, antihistamines, or other medications.

• Stress-related overgrooming might improve with environmental enrichment or anxiety-reducing strategies.

• Fungal infections are treated with antifungal medications.

  
  

It’s important to note that there’s no one-size-fits-all fix. What works for one cat might not work for another, so getting a proper diagnosis is crucial.

It is important to regularly treat any cats with skin disease for external parasites. This can be done with easy to administer topical preparations.

When Should You Book an Appointment?

Any time you notice unexplained hair loss in your cat—especially if it’s paired with itching, redness, sores, or changes in behaviour—it’s best to get it checked out. Alopecia is often a sign that something else is going on under the surface, and early intervention can help prevent it from getting worse.

While a bald patch might not seem urgent, it can offer valuable clues about your cat’s health. Whether it’s a minor irritation or part of a larger medical picture, paying attention to your cat’s coat is a smart way to stay on top of their well-being.