The Dangers of Flea Bites for You and Your Pet

A Chartreux lying and scratching its ear.

Fleas don't just cause itching and skin irritation in dogs and cats — their bites can also lead to far worse health issues. But did you know a flea infestation can also cause health problems for your family? Regardless of who they bite, the dangers of fleas extend beyond skin irritation.

Dangers to You and Your Pet

The most common fleaborne diseases and illnesses that can impact both you and your pet include:

Flea Allergy Dermatitis

Most commonly, fleas cause itchy skin in cats and dogs. But in some cases, they can wreak further havoc. Many animals are allergic to flea saliva, and flea bites can cause flea allergy dermatitis. When a cat or dog continues to scratch at the bite, it can cause swelling, irritation, welts and eventually broken skin, which can lead to skin infection and pain.

If your cat or dog has flea allergy dermatitis, your veterinarian may recommend an oral, topical or injected medication to help ease the irritation and prevent further itching. Additionally, your vet may prescribe an antibiotic if an infection has developed. Make sure to consult your veterinarian on any treatment plans.

Humans can also be susceptible to flea allergy dermatitis. They can suffer from an allergic reaction to flea bites that causes severe itching, skin irritation and possibly infection. In some cases, this intense skin discomfort can temporarily impact quality of life, making it hard for you to sleep and go about your daily activities.

A close-up of a human hand applying cotton pad on a dog’s red skin area.


Bartonella is a flea transmitted illness in cats and potentially dogs. It is often associated with numerous conditions including heart disease, eye inflammation and seizures.

To treat bartonella, veterinarians often prescribe antibiotics for up to six weeks. In some situations, if a cat is not showing any symptoms and is acting fine, treatment may not be pursued.

Humans can contract bartonella, also known as cat scratch fever, if their cat scratches them while they have flea bacteria on their claws. Serious symptoms can include eye infections, encephalitis (swelling of the brain), fever and severe muscle pain.


Cats and dogs may also contract tapeworms from ingesting a flea. This is especially common when pets groom themselves, particularly in an attempt to soothe irritated skin. If your dog or cat has fleas and you suspect they have a tapeworm, take them to the veterinarian for an exam and treatment. You can also purchase many tapeworm treatments in pet stores or online. Without treatment, tapeworms can slowly rob your pet of nutrients, eventually leading to weight loss.

Though rare, pet owners can also unknowingly ingest fleas and the tapeworms fleas carry. They can then develop tapeworm as a result, which can lead to nausea, vomiting, diarrhea and other intestinal issues.

Other Dangers to Your Pet

Fleas are blood-sucking parasites, and if they continue feasting on cats or dogs for any length of time, the pet may develop anemia. This condition can cause lethargy at the very least and may even cause death in puppies, kittens or older pets.

To treat anemia in dogs and cats, your veterinarian may suggest intravenous fluids, antibiotics and, in severe cases, blood transfusions.

How Can Pet Owners Prevent Fleas?

Although it is possible to get rid of fleas once they have infested, pet owners should try to protect their dogs and cats from becoming infested in the first place. Talk to your pet's veterinarian about flea and tick preventives, which are available in a variety of forms including chewables, topical treatments and collars, to address a flea problem before the insects attack.

Related articles:
Everything You Need to Know About the Flea and Tick Life Cycle
How to Help Get Rid of Fleas on Your Cat
How Does Weather Affect the Flea and Tick Population?

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