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The Dangers of Flea Bites on Cats: 4 Common Flea Diseases in Cats

When cats get bitten by fleas, they experience a lot of itchiness, annoyance, and discomfort. But did you know the dangers of fleas go beyond bites and itchiness? There are many flea-borne and flea-related diseases that affect cats. The more you understand about these dangers, the more you can do to prevent flea infestations and diseases for your own cat. 

Common Flea Diseases and Conditions in Cats

Fleas can transmit many diseases to cats through bites. Here are some of the ways fleas can affect your cat’s health. If administering flea protection to your cat, always remember to check the product label for specific disease indications.

Flea Allergy Dermatitis (FAD)

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Some cats are particularly sensitive to flea saliva. As a result, some cats may end up suffering from an allergic reaction called flea allergy dermatitis, or FAD.1


With FAD, the flea’s saliva triggers immune responses in your cat. This causes skin irritation that can extend past the initial location of the flea bite. This may result in hair loss from scratching around your cat’s tail, belly, and inner thighs. 


Signs of FAD include small, scab-like bumps on the skin, or even skin infections in some cases. This condition will continue until the fleas are controlled.  

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Another flea disease that affects cats is bartonellosis. This is a bacterial infection that cats can get after being bitten by an infected flea or encountering contaminated blood.1 Cats don’t typically show signs of infection, but in severe cases, bartonellosis may cause fever, lethargy, swollen lymph nodes, and/or decreased appetite.2


The most common type of bacterium responsible for bartonellosis, Bartonella henselae, can also affect humans, causing a condition known as cat scratch disease. This occurs when an open scratch is contaminated with flea stool. An infected cat licking someone’s open wound can also spread the bacteria. Symptoms of cat scratch disease in humans include fever, enlarged lymph nodes, or pustules at the site of the infection.3 


If enough fleas bite and feed from your cat, your cat may develop anemia. Signs of anemia include weakness, lethargy, rapid breathing, or even death, if the fleas are not managed. This can be a life-threatening medical condition, particularly in kittens, and should be addressed with veterinary care as soon as possible.1  

Tapeworm Infection

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Your cat can become infected with tapeworms if they accidentally ingest an infected flea, which can happen during grooming.1 After the flea is ingested, the tapeworm egg is released. It hatches and then anchors itself to your cat’s intestinal lining. 


Cats can’t become infected by simply ingesting the tapeworm egg—infection occurs only via the intermediary host, which is the flea. This is why tapeworms are most common in environments where severe flea infestations exist.4 


If your cat is infected with tapeworms, it’s possible you could see tapeworm eggs near your cat’s bottom, in their feces, or in their environment. They will look like tiny seeds or grains of rice.4 Although the discovery of tapeworms may be alarming, tapeworm infections rarely cause serious medical problems in cats.  

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How to Address Flea Diseases in Cats

The most effective way to combat flea-related illness in cats is to prevent flea infestations. This is important even if your cat never goes outdoors! Even indoor cats are at risk of getting fleas and suffering from flea-related illnesses.

Signs of Flea Bites on Cats

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Regularly checking your cat for fleas can help you catch the problem before it turns into a flea infestation. If your cat allows it, turn him or her on their back to perform the check. If not, you can also run your fingers through his or her fur, going against the direction of the hair, to look for adult fleas on the skin. 


When performing a flea check, pay special attention to areas where fleas may hide. This includes the armpits, belly, and groin. 


During a visual check, look for red bumps on your cat’s skin. There may also be patches of fur missing from excessive scratching or licking. If your cat has an allergic reaction to flea saliva, you may even notice scabs on or around the flea bites. 


A handy tool to use during these checks is a flea comb, which has narrow teeth designed to catch and pull fleas from the cat’s coat. Run the comb through your cat’s fur and rinse it in a bowl of soap and warm water between passes.

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Treating for Fleas

Fleas reproduce at an alarming rate, with adult females laying up to 50 eggs each day.5 If you find any fleas on your cat, it’s important to kill them before they multiply and cause a full-blown flea infestation. 


Use topical products to kill any live fleas on your cat. The best course of action is to find a product that acts against flea eggs and larvae while also killing adult fleas before they have a chance to lay eggs, thus putting an end to the flea life cycle.

Flea Prevention

Getting rid of the live fleas on your cat is the first step. Next, it’s time to take some preventative measures to help keep your cat and your home free of fleas. Here are some tips for keeping fleas off your cat and out of their environment: 

  • Routine Cleaning: Vacuum your carpets and furniture and wash all bedding frequently. Give extra attention to areas where your cat spends a lot of time. This can help eliminate any flea eggs or larvae in your pet’s environment. (Tip: after vacuuming, be sure to empty the bag outdoors instead of inside your house.) 
  • Yard Maintenance: There are many ways you can make your yard less inviting for fleas. These include mowing the grass regularly, using a pet-friendly insecticide like diatomaceous earth, and raking up leaves and brush.
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Treat With Monthly Flea and Tick Protection

Treating your indoor cat with monthly preventive products is the best plan of attack when it comes to protecting against fleas (and don't forget to treat all animals in your house with an appropriately approved product, too). FRONTLINE® Brand Products kill existing adult fleas and act against flea eggs and larvae, preventing future infestations.