Worms in Cats’ Eyes

Eyeworms, also known as Thelazia californiensis, are parasitic worms that can infest the eyes of cats, causing discomfort and potential vision problems.

We will explore the causes, symptoms, and treatments for worms in cats’ eyes, as well as provide important tips for prevention. So, if you want to ensure the well-being of your feline companion, keep reading to learn everything you need to know about this alarming condition.

What are worms in cats’ eyes (eyeworms) and how do cats get them?

Eyeworms, also known as worms in cats’ eyes, are parasitic worms that infect the eyes of cats. They belong to the Thelazia genus of nematodes and are primarily found in the conjunctival sac, which is the space between the eyelids and the surface of the eye.

Cats can get eyeworms through the transmission of infective larvae from flies or other insects that serve as intermediate hosts. When the flies feed on the ocular discharge or tears of infected cats, they can pick up the larvae and subsequently transmit them to other cats during feeding. This transmission can occur both directly or indirectly through contaminated surfaces, such as shared bedding or grooming equipment.

Once the larvae enter the cat’s eye, they develop into adult worms within the conjunctival sac. These adult worms can cause various eye-related symptoms, including excessive tearing, conjunctivitis, redness, swelling, and discharge. In severe cases, they can even damage the cornea and lead to vision problems.

Symptoms of worms in cats’ eyes and when to seek veterinary help

  • Redness and Irritation: Cats with worms in their eyes may experience redness and irritation in the affected eye(s). This can manifest as excessive blinking, squinting, or pawing at the eye.
  • Excessive Tearing: Worms in a cat’s eye can cause increased tear production, leading to watery eyes and tear-stained fur around the eye area.
  • Cloudy or Hazy Appearance: The presence of worms can lead to a cloudy or hazy appearance in the affected eye, impairing vision.
  • Eye Discharge: Infected cats might have a thick, yellowish or greenish discharge coming from the eye. This discharge can be accompanied by a foul odor.
  • Sensitivity to Light: Affected cats may show increased sensitivity to light, avoiding bright areas or squinting in well-lit environments.
  • Swollen or Inflamed Eyelids: In some cases, worms in the eyes can cause swelling or inflammation of the eyelids.
  • Behavioral Changes: Cats with worms in their eyes may exhibit changes in behavior, such as increased restlessness, decreased appetite, or decreased activity levels.

If you notice any of these symptoms in your cat’s eyes, it is important to seek veterinary help promptly. A veterinarian will be able to diagnose the presence of worms and recommend the appropriate treatment plan. Remember, early detection and treatment are key to preventing complications and ensuring your cat’s overall eye health.


Diagnosing worms in cats’ eyes (eyeworms) can be challenging, as the symptoms can be similar to other eye conditions. To accurately diagnose eyeworm infestations, a veterinarian may perform the following procedures:

  1. Physical examination: The vet will thoroughly examine the cat’s eyes for any signs of inflammation, redness, discharge, or foreign bodies.
  2. Fluorescein stain test: This test involves applying a special dye to the surface of the eye to detect any abnormalities in the cornea, such as scratches or ulcers.
  3. Tear film break-up time (TFBUT) test: This test measures the stability of the tear film on the surface of the eye. Eyeworms can disrupt tear production and cause a decrease in the TFBUT.
  4. Diagnostic imaging: In some cases, the vet may recommend imaging tests, such as ultrasound or X-rays, to visualise any structural changes or the presence of worms within the eye.

If eyeworms are suspected, the veterinarian may collect a sample of the eye discharge or perform a conjunctival swab to identify the species of worm present. Laboratory tests, such as microscopy or DNA analysis, can confirm the presence of eyeworms and guide the appropriate treatment for the cat. Early diagnosis is crucial to prevent further complications and protect the cat’s vision.

Treatment options for eyeworms in cats

When it comes to treating eyeworms in cats, there are several options available. The most common treatment method involves the use of antiparasitic medications that target the worms and eliminate them. These medications are typically administered orally or topically, depending on the severity of the infestation and the specific medication being used.

In some cases, if the eyeworm infestation is severe or if the cat is experiencing complications, surgical intervention may be necessary. This involves removing the worms manually from the cat’s eyes under anesthesia.

It’s important to note that treatment for eyeworms in cats should always be carried out under the supervision of a veterinarian. They will be able to assess the severity of the infestation and recommend the most appropriate treatment plan for your cat.

Here are a few key points to remember when it comes to treating eyeworms in cats:

  • Antiparasitic medications are the most common treatment option for eyeworms in cats.
  • Medications can be administered orally or topically, depending on the severity of the infestation.
  • Surgical intervention may be necessary in severe cases or if complications arise.
  • Always consult with a veterinarian for proper diagnosis and treatment recommendations.
  • Regular check-ups and preventative measures, such as deworming, can help prevent eyeworm infestations in cats.

Prevention measures to protect your cat from eyeworm infestations

  1. Regular Veterinary Check-ups: Schedule regular check-ups with your veterinarian to monitor your cat’s overall health and identify any potential signs of eyeworm infestations.
  2. Keep the Environment Clean: Maintaining a clean living environment for your cat can help reduce the risk of eyeworm infestations. Regularly clean your cat’s bedding, litter box, and surrounding areas.
  3. Prevent Contact with Infected Animals: Limit your cat’s interaction with stray or infected animals, as they can potentially transmit eyeworms. Be cautious when introducing new cats into your household.
  4. Control Fleas and Ticks: Fleas and ticks can carry eyeworm larvae. Use preventative measures such as flea and tick treatments to protect your cat from these parasites.
  5. Practice Good Hygiene: Wash your hands thoroughly after handling other cats or any contaminated objects to prevent the spread of eyeworms.
  6. Regular Eye Checks: Monitor your cat’s eyes regularly for any signs of irritation, redness, discharge, or unusual behavior. If you notice any changes, consult your veterinarian promptly.

Always consult with your veterinarian for specific prevention measures based on your cat’s individual needs and circumstances. By following these prevention measures, you can help protect your cat from eyeworm infestations and ensure their overall well-being.

Worms in Cats' Eyes

Importance of regular check-ups for your feline friend

Regular check-ups with a veterinarian are essential for maintaining your cat’s overall health and well-being. When it comes to worms in cats’ eyes, regular check-ups can help detect any infestations early on and ensure prompt treatment.

During a check-up, the veterinarian will thoroughly examine your cat’s eyes, looking for any signs of eyeworms or other eye conditions. They may also perform additional tests, such as swabs or microscopic examinations, to confirm the presence of eyeworms.

Regular check-ups also provide an opportunity for the veterinarian to assess your cat’s general health, administer preventive treatments for worms, and address any other concerns you may have regarding your cat’s eye health.

In addition to eye health, regular check-ups allow the veterinarian to monitor your cat’s overall health, detect any underlying conditions or diseases early on, and provide appropriate preventive care.

Remember, prevention is always better than cure. By scheduling regular check-ups for your feline friend, you can help ensure their eyes and overall health are kept in optimal condition.

Reyus Mammadli/ author of the article

I have had pets since childhood: cats, guinea pigs, rabbits, geese, chickens, ducks, parrots, aquarium fish and dogs (in the yard). Of course, I constantly encountered diseases of pets and treated them. Glad to be able to share my skills and experience, as well as advice on caring for and adapting these critters and birds.

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