VCA Aspenwood Animal Hospital

Parasites in Cats: Worms, Mites, Ticks, & Fleas

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  • You can’t treat heartworms in your cat, you can only prevent them

  • Ear mites are highly contagious and can move from cat to cat

  • Some internal parasites can be transmitted to humans

The Truth about Parasites in Cats

Parasites are organisms that thrive by feeding off of other creatures. Cats can easily fall prey to both internal and external parasites, which pose different challenges when it comes to detection. A close inspection of your cat's skin might uncover traces of external parasites such as ear mites and fleas. But internal parasites, such as ringworms or coccidia, may require some tests to determine medication.

Discover Which Cat Parasite Risks Exist in Your Area

Parasite Prevalence Maps

Use this Parasite Prevalence Maps by the Companion Animal Parasite Council (CAPC)* to get important information about your region’s parasite risk.

*Images courtesy of the Companion Animal Parasite Council (CAPC)

Some infected cats have no symptoms. Although infrequent, sudden death is a reported occurrence in cats, as they hide very well more subtle symptoms. The only way to detect and properly treat internal parasites is through testing.

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There are many parasites that can be harmful to your cat’s health. Let’s take a closer look at some of them.

Worms in Cats

These tiny worms live inside the blood vessels, and travel to the cat’s lungs. Undetected, they can cause severe health problems and even death. They are transmitted through mosquito bites which means even your indoor cat could be at risk.

Known to cause life-threatening problems in kittens, these large bodied worms average 3-6 inches in length. They do not attach to the wall of the intestine, as some intestinal parasites do— instead they “swim” freely within the intestine. Known to cause abdominal discomfort and vomiting, roundworms are easily treated if detected early enough.

The name “hookworm” is derived from the hook-like mouthparts these parasites use to anchor themselves on the lining of the intestinal wall. So small, they are barely visible to the naked eye, but they feed on the tissue fluids and blood of their host.

Cats commonly contract tapeworms via accidentally ingested fleas. Once the flea is digested by the cat’s intestine, the tapeworm is released into the cat’s system. Eventually segments of the worm pass in the cat’s feces and are visible to the pet owner.

Skin Diseases and Parasites in Cats

Surprisingly, ringworm is not a true worm, but rather a type of fungus. Usually, it doesn’t cause discomfort but it can be easily transmitted to other cats and even humans. Left untreated, it can weaken your cat’s immune system and make it easier for her to contract other, more serious, diseases.

They are found in grassy or wooded areas and can attach themselves to you and your pet as you pass by. Although a tick’s bite does not itself pose a direct threat to your pet’s health, it can transmit serious (and sometimes fatal) diseases such as Lyme disease and Rocky Mountain fever.

Ear Mites
As these microscopic parasites feed in a cat’s ear canal, they cause intense itching. A cat suffering from ear mites may be seen repeatedly scratching at her ears or violently shaking her head. If you see dark flecks resembling coffee grounds in your cat’s ears, these are the mites' droppings. Contact your vet for ear drops.

Fleas can make any cat’s life miserable (and their family’s)! These small, blood-sucking insects like to feed on your cat and live anywhere your cat does. Fleas can quickly cause a long-lasting, major infestation in your home. Not only can fleabites cause discomfort, itchiness and severe skin reactions, they can potentially transmit tapeworms if accidentally ingested by your cat.

Other Internal Parasitic Cat Diseases

Coccidia are not parasitic intestinal worms. They are microscopic parasites that live within cells of the intestinal lining. Because they live in the intestinal tract and commonly cause diarrhea, they are often confused with worms. In kittens and debilitated adult cats, coccidiosis may cause severe, watery diarrhea, dehydration, abdominal distress, and vomiting.

Three Ways to Protect Against Parasites in Cats

Get your Cat Tested Regularly
While it’s fairly common for a cat to become infected with an internal or external parasite at some point, early treatment is crucial. A harmless parasite left untreated could eventually cause a life-threatening illness for your cat and pose a health risk to your family.

Focus on Prevention First
Preventative medicine is much better option than treatment later. Getting your kitten or cat vaccinated and de-wormed regularly allows her immune system to thrive, which most likely translates to your cat needing less care later. Adult cats also benefit from fecal examinations — which allow your vet to diagnose parasites not controlled by monthly medications.

Annual Checkup to Stay Healthy
Bringing your cat to the veterinarian for regular parasite checkups is one of the most important things you can do to keep your pet, and your family, healthy. We offer different programs specifically designed for your cat’s stage of life. Schedule an appointment to find out more.

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Learn More About How to Prevent and Treat Parasites »

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Specialty Care

Sometimes sick or injured pets need the care of a veterinary medical specialist. When that happens, VCA specialty hospitals work closely with the general practitioner veterinarians who refer cases to us in order to provide seamless veterinary care to your pet. When your pet is facing any kind of serious illness or injury, our specialty referral hospitals will provide the compassionate and expert care your beloved pet needs.

Our goal is to make sure that when you and your pet are in need that you have access to board certified specialists who are up to date on the very latest developments in their field. In our state of the art hospitals, our specialists also have access to the most sophisticated diagnostic and treatment tools and techniques from ultrasonography and endoscopy to CAT scans and even MRI.

As part of the VCA family, we have over 83 specialty hospitals across the US and Canada which provide referral specialty care, so there may be one near you. Our specialized services include: behavior, cardiology, critical care, dentistry, dermatology, integrative medicine, internal medicine, neurology, oncology, ophthalmology, radiology, rehabilitation, reproduction, and surgery.

Find a VCA Specialty Care Animal Hospital near you:


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Emergency Care

In case of emergency, please call us immediately. If it is after hours, check with a local animal hospital emergency clinic.

VCA Alameda East Animal Hospital

9770 E. Alameda Ave Denver, CO 80247


Veterinary Referral Center of Colorado

3550 S. Jason St Englewood, CO 80110


Wheat Ridge Animal Hospital

3695 Kipling St Wheat Ridge, CO 80033


Animal Emergency & Specialty Center

17701 Cottonwood Dr Parker, CO 80134