Cat Parasites: How to Spot an Infection and Protect Your Cat

Whether your cat lounges on a windowsill or prowls the backyard, parasites can disrupt their leisure time and threaten their well-being. Tiny but persistent, parasitic pests can be a mild annoyance or a serious health threat. With routine screening and prevention, you can keep your cat safe — or start treatment to help your feline friend recover from a parasitic infection and get back to living their nine lives to the fullest.

What Are Cat Parasites?

Parasites are organisms that live on or inside your cat, feeding off their blood, the nutrients they eat or other tissues to survive. While some parasites, such as fleas and ticks, are visible to the naked eye, most are more difficult to detect.

Cat parasites are divided into two categories:

• External parasites. These live on a cat’s skin or in their ears.
• Internal parasites. These live inside a cat’s body, such as inside their intestines, lungs or heart.

Some parasites can infect your cat without causing any obvious signs, while others can cause discomfort or potentially serious health consequences, such as dehydration or anemia. Kittens, senior cats and cats with weakened immune systems are usually more severely affected by parasites than healthy cats are.

Types of Cat Parasites

Cats can be affected by a wide range of parasites. The likelihood of contracting a particular parasite depends on a cat’s lifestyle, health and geographic location.

The table below outlines some of the most common parasites that affect cats in the United States, including how each parasite is spread and signs to watch for in your cat. Keep in mind that symptoms can vary between cats; some cats may show no signs, while others may become seriously ill.

Cat Parasites and Climate Considerations

Your location can affect your cat’s likelihood of exposure to parasites. Warm, humid environments create ideal conditions for parasites like fleas and mosquitoes, while cooler or drier areas may see more seasonal activity.

However, parasites don’t completely disappear when the weather turns cold. Many can survive year-round inside homes or on their living hosts, and some cats hunt prey indoors or in outbuildings. Indoor cats are also at risk, as other pets or people can bring parasite eggs indoors, and mosquitoes or fleas can slip through window screens.

Regardless of the climate, it’s essential to talk with your veterinarian about parasites in your region and follow their guidance on prevention.

Can Cats Pass Parasites to Humans?

Some parasites that affect cats can also cause health problems in people, especially young children, older adults and those with weakened immune systems. These zoonotic parasites spread to people through direct contact or contact with contaminated feces, soil or surfaces. However, most parasites have a preferred host species, and if they do infect other hosts, the effects are often different from those seen in cats.

Examples of how cat parasites could affect people include:

• Although cats are relatively resilient to tick-borne diseases, ticks carried inside by your cat can bite people and transmit Lyme disease or other tick-borne illnesses.
• Roundworm larvae ingested by people can migrate to internal organs, including the brain and eyes, and form cyst-like structures. Children are the most susceptible.
• Toxoplasma gondii can infect humans through contact with contaminated feces or soil. Pregnant women and people with weakened immune systems are the most likely to develop problems.

Overall, transmission of parasites from cats to people is uncommon. You can prevent this by practicing good hygiene, including scooping litter boxes daily, cleaning them often and washing your hands after handling your cat.

Signs of Parasites in Cats

Many cats with parasites don’t show obvious signs. However, you may notice symptoms in younger or sensitive cats, or those with poor immune function.

Possible signs of external parasites in cats include:

• Dull coat or flaky skin
• Hair loss
• Head shaking or ear discharge
• Scratching and excessive grooming
• Visible fleas or ticks

Possible signs of internal parasites in cats include:

• Bloated or distended abdomen
• Coughing or wheezing
• Diarrhea
• Lethargy or weakness
• Pale gums
• Visible worms or worm segments in the feces
• Vomiting
• Weight loss (adults) or failure to grow (kittens)

Diagnosing Cat Parasites

Veterinarians use a combination of methods to diagnose parasites in cats. Your vet may recommend screening your cat once or twice a year for parasites, or more frequently if your cat goes outdoors. They may also recommend testing if your cat shows signs of an infection.

Tests to help diagnose parasites include:

• A physical exam to check for external parasites
• Blood test to check for heartworms
• Fecal test to check for eggs or parasite DNA in feces
• Skin scraping to check for mites

Treatment Options for Cat Parasites

Treatment for parasites in cats depends on the type of parasite your cat has.

Antiparasitic medications

In most cases, your veterinarian will prescribe one or several doses of a medication that targets the specific parasite. The medication may be oral, topical or injectable, depending on the parasite your cat has.

If you have other pets, they may need testing and treatment as well. Never treat your cat with products labeled for dogs, as many of these medications are toxic to cats. Always follow your veterinarian’s instructions regarding parasite treatments.

Environmental decontamination

Getting rid of parasites usually also requires “treating” your cat’s environment. This may involve cleaning indoor areas (e.g., washing bedding and vacuuming) and eliminating outdoor areas where parasites may hide.

Heartworm treatment in cats

Heartworm infections are particularly challenging to treat because there are no safe drugs that kill adult heartworms in cats. Treatment focuses on minimizing inflammation caused by the worms, addressing the cat’s symptoms and supporting their health until the worms die naturally.

Tips for Preventing Cat Parasites

Preventing parasites is usually easier and less expensive than treating an active infection or infestation. Whether your cat lives indoors or ventures outside, a few simple habits can help you protect their health. Components of a parasite prevention plan include:

• Clean litter boxes. Maintaining a clean litter box by scooping daily and disinfecting regularly reduces the transmission of parasites to other pets or people.
• Indoor lifestyle. Keeping your cat indoors reduces their exposure to infected animals and prey.
• Parasite checks. Checking your cat regularly for signs of fleas, ticks and ear mites can help you intervene before the issue gets worse.
• Preventive medications. Topical, oral or collar formulations provide long-lasting protection against a broad spectrum of parasites.
• Routine veterinary care. Regular vet visits, including fecal exams and heartworm screenings, ensure prompt treatment for parasites you can’t see.

Proactive prevention helps your cat stay healthy and can also protect other pets and people in your household and community.

Protecting Cats From Pesky Parasites

Parasites may be small, but they can have a big impact on your cat’s health. From intestinal worms to skin mites, these pests can cause discomfort and illness. Fortunately, most parasite problems are preventable with consistent veterinary care and year-round protection.

CareCredit Credit Card Financing for Cats

The CareCredit credit card is an easy way to pay for your cat’s annual checkups, food and products at veterinary practices in the CareCredit network.* Use our Acceptance Locator to find a veterinarian near you that accepts CareCredit to help keep your pet healthy and happy for a lifetime of love. CareCredit is there for you and your pet every step of the way; continue your wellness journey by downloading the CareCredit Mobile App to manage your account, find a provider on the go and easily access the Well U blog for more great articles, podcasts and videos.

In addition to pet care, you can also use your CareCredit credit card for dentistry, cosmetic, vision, hearing, health systems, dermatology, pharmacy purchases, spa treatments and so much more within the CareCredit network. How will you invest in your health and wellness next?

Author Bio

Angela Beal, D.V.M., has more than 20 years of experience as a veterinarian. Leveraging her background in private practice and academia, she uses her passion for writing to convey information to pet owners to help them keep their pets healthy and happy.