How to Tell if a Cat Has Fleas

Dr. Joe Alcorn, M.S., D.V.M.

Dr. Joe Alcorn is founder of Care Animal Hospital in Temecula, California. He has a Bachelor of Science in Biology and Doctor of Veterinary Medicine from Colorado State University. He is a member of the American Veterinary Medical Association and his advice has been featured in large publications like Bustle and Martha Steward.

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When warm weather kicks in, your purr-fect cat may have some unwanted and potentially dangerous guests. Fleas can attack your cat at any time of the year, but they are most active when it is warm. Look out for them when the humidity hits 70 percent and temperatures are about 35°C. Learning how to tell if a cat has fleas and what to do about them can help you address this issue before it becomes a big problem for your cat.

How to Tell If a Cat Has Fleas

Fleas are more than just unsightly. They are pests in every sense. They feed on your cat’s blood and burrow into their fur, making it itchy and inflamed. Here are a few ways to find out if your cat has fleas. 

Avoiding Some Parts of Your Home

If you realize that your cat is suddenly avoiding some parts of your home, it probably has fleas. The pests thrive in warm environments with porous surfaces. They may include furniture, tile flooring, and carpeting. Your cat may start avoiding those areas as a way to avoid fleas. If their bed is infested with fleas, they may avoid it too. While this isn’t always a sign of fleas, it can be.

Cat with fleas scratching its skin

Scratching and Biting

Flea bites can be very irritating to your cat’s fur. They can cause itchiness and intense discomfort. If your cat suddenly seems to be scratching vigorously and chewing on its skin, it probably has fleas. The best solution to this issue is as soon as possible use a cat flea shampoo to save from itchy problems. There are lots of helpful after-bath treatments as well. 

Experiencing Muscle Loss, Lethargy, and Pale Gums

If your cat displays signs of unexplained lethargy, pale gums, or muscle loss, they may have anemia. This is probably the result of a flea infestation. When a considerable number of fleas feed on your cat’s blood or the cat bites its own skin deeply, it may bleed excessively. Flea anemia is most common in sick cats, kittens, and seniors. However, it can affect healthy cats as well.

You Can See Them

When your cat is infested with fleas, you may be able to see them. Adult fleas can be up to 1/8th of an inch long. They are thin and red-brown. Although they may not be visible in cats with darker coats, they may be easier to spot on light-colored fur. For every adult flea on your cat’s fur, there are over 100 immature ones. You may also notice the cat’s fur moving randomly.

Even if you don’t see the fleas, you may be able to see ‘flea dirt.’ It looks like loose pepper or dust. Look out for it on your cat’s carpet, bedding, their skin, or the areas they like to hang out. 

Suspicious Activities at Home

When your cat is infested with fleas, you may see other suspicious activities in your home. The pests lay tiny white eggs around your house. They may be present on your carpets, their bed, or the general environment.

You may see squiggly little things around as well. After a while, there may be red-brown specks of your cat’s blood around. If you catch pinkish or white tapeworms slipping out of your cat’s rectum, it may have been battling with fleas. 

Irritated-Looking Skin and Scab-Like Bumps

Check your cat’s skin under its fur. If it looks reddish and irritated, your cat is probably struggling with fleas. Check the base of the tail, the back, and the neck. Bite marks are an indication that things aren’t well. Flea bites can also cause flea allergy dermatitis. It causes scars, redness, and itchiness. The allergy could trigger secondary skin infections. 

Some cats are sensitive to flea saliva. After a flea bite, they may develop itchy lesions that eventually start oozing. Some may develop scab-like bumps. You need to come and get prescription medication as soon as possible. 

Excessive Grooming and Hair Loss

Look out for signs of unexplained hair loss in your cat. While fleas don’t necessarily cause it by themselves, this may result from excessive biting and scratching. Usually, hair loss is most prominent at the shoulder blades and neck of your cat. The cat’s belly may be visibly bare. 

Although cats can be fastidious with their grooming habits, you must know when they are getting extreme. They are probably struggling with fleas if they are excessive, especially around the tail base and hind legs. They may groom so hard that they start to develop bald patches. 

Cat with thick fur

Restlessness and Agitation

The discomfort from flea irritation can make your cat restless and irritable. If your once precious, cuddly little kitty now acts like a wildcat or no longer wants to sit still for too long, it probably has a few fleas driving it crazy. The restless behavior may include rubbing their body and head against the walls or floor, rolling on the ground, or jumping from one end of the room to another. 

What to Do If Your Cat Has Fleas

If you suspect that your cat may have fleas, you need to act urgently. Flea-related anemia can be fatal. The first step is thoroughly cleaning your entire home. Focus on the carpeting, beds, corners, and floors. Unless you completely eliminate fleas in all their development stages, they will always be a problem. 

Put all of your cats’ fabrics and bedding in a trash bag and clean them with hot soapy water. Vacuum every area that your cat enjoys hanging out to get rid of flea eggs. Bring your cat to me and  I will begin treatment as soon as possible. The recommended treatment options include:

  • Use shampoos and topical treatments to kill flea eggs, lice, and mature fleas
  • Take advantage of flea collars to keep the pests away
  • Give your cat flea chewable and pills for fast pain and irritation relief
  • Get a professional flea exterminator 
  • Treat your outdoors just as well as your indoor space. If you cannot, keep your cat indoors. 


If your cat has fleas, there are a few ways to know. Unfortunately, the pests can cause significant health issues if not treated on time. In some instances, a flea infestation can be fatal. If you realize that your cat has fleas, seek medical attention as soon as possible.