If your cat just vomited worms, your cat has an intestinal parasite infection that needs treatment. The good news: this is one of the most common feline health issues, it’s very treatable, and your cat will almost certainly be fine once you get the right medication. The immediate step is to call your vet and schedule an appointment, ideally within the next day or two.
In the meantime, there are a few things you can do right now, and a few things worth understanding about what you’re looking at.
Identifying the Worms You’re Seeing
The two parasites cat owners most commonly spot are roundworms and tapeworms, and they look quite different from each other.
Roundworms resemble small pieces of spaghetti. They’re white or light tan, smooth, and typically 3 to 6 inches long. When vomited up, they may be alive and moving, or limp and still. These are by far the most common intestinal parasite in cats.
Tapeworms look completely different. You’re more likely to see small, flat, rice-grain-sized segments near your cat’s rear end or in their stool than in vomit, though heavy infections can cause vomiting too. The segments are white or cream-colored and may appear to wiggle slightly when fresh.
Less commonly, cats can carry stomach worms that are only detected when the cat vomits them up or when larvae are found in the vomit. These are harder to identify visually. If what you’re seeing doesn’t match the roundworm or tapeworm description, take a photo or collect a sample for your vet.
What to Do Right Now
Clean up the vomit promptly while wearing gloves. Roundworm eggs can be infectious to humans, so you want to minimize contact. Place the vomit in a sealed plastic bag and dispose of it. If possible, save a small sample (a spoonful in a sealed bag or container) to bring to your vet. This can help them identify the exact parasite without waiting for test results.
Clean the area where your cat vomited. For hard floors, a bleach solution of one part bleach to four parts water helps strip the sticky outer coating off roundworm eggs, making them easier to remove. For carpet, blot and clean thoroughly, then steam clean if you can. Roundworm eggs are extremely resilient. Bleach won’t actually kill them, but it loosens their protective layer so they can be physically removed from surfaces.
Keep children away from the area until it’s fully cleaned. Wash your hands thoroughly after handling anything related to the cleanup, the litter box, or your cat’s bedding.
What Happens at the Vet
Your vet will likely run a fecal flotation test, which involves examining a stool sample under a microscope to identify parasite eggs. This test typically costs around $22 to $30 at most clinics, though your total visit will include an exam fee as well. The fecal test tells your vet exactly which parasites are present, since cats can carry more than one type at a time.
If you vomited-up worms are clearly roundworms, your vet may skip straight to treatment based on the visual identification alone. Treatment is a deworming medication, either given orally or applied topically. Some modern topical products treat multiple parasites (fleas, ticks, and intestinal worms) in a single application. Your vet will choose the right product based on which parasites your cat has.
Most deworming treatments require at least two doses, spaced a couple of weeks apart. The first dose kills the adult worms. The second dose catches any larvae that have since matured. Don’t skip the follow-up dose even if your cat seems perfectly fine after the first one.
How Your Cat Got Infected
Cats pick up roundworms by swallowing the microscopic eggs from contaminated soil, grass, or surfaces, or by eating infected prey like mice or birds. Kittens frequently get roundworms directly from their mother, either before birth or through nursing. If your cat goes outdoors or hunts, reinfection is an ongoing risk.
Tapeworms usually come from swallowing an infected flea during grooming. If your cat has tapeworms, a flea problem is likely part of the picture, and you’ll need to address both.
Some stomach worms spread when a cat ingests the vomit of another infected cat, which is relevant in multi-cat households or environments like shelters and catteries.
Signs Your Cat May Have a Heavy Infection
Vomiting worms typically means the infection has been building for a while. Other signs to watch for include:
- Weight loss despite a normal or increased appetite
- A pot-bellied appearance, especially in kittens
- Dull, rough coat
- Diarrhea, sometimes with visible worms or blood
- Scooting (dragging their rear on the floor)
- Decreased energy or general listlessness
Kittens with heavy roundworm infections can become seriously ill. They’re at risk for intestinal blockages, malnutrition, and stunted growth. Adult cats tolerate worm infections better, but a heavy parasite load still takes a real nutritional toll over time. If your cat is a kitten, very thin, or showing multiple symptoms, mention that when you call the vet so they can prioritize the appointment.
Protecting Yourself and Your Family
Cat roundworms can infect humans through a condition called toxocariasis. This happens when someone accidentally swallows roundworm eggs, usually from contaminated soil or unwashed hands after gardening or handling litter. The CDC notes that it doesn’t spread person-to-person like a cold or flu, and many infected people never develop symptoms at all.
When symptoms do occur, they fall into two categories. The more common form causes fever, coughing, wheezing, and abdominal pain. A rarer form affects the eyes, causing redness, vision changes, or seeing spots and flashes of light, typically in only one eye. Children are at higher risk because they’re more likely to put dirty hands in their mouths.
Practical steps to protect your household: wash hands after cleaning the litter box, keep the litter box scooped daily (roundworm eggs need a couple of weeks in the environment to become infectious), and keep children’s sandboxes covered when not in use. If your cat has been defecating in garden beds, wear gloves when working in those areas.
Preventing Reinfection
Once your cat is treated, the goal is keeping them parasite-free going forward. Regular deworming on a schedule your vet recommends is the most reliable approach. Many vets suggest deworming indoor-outdoor cats every three months, while indoor-only cats may need it less frequently.
Flea prevention is essential, since fleas are the primary transmission route for tapeworms. Keeping your cat on a year-round flea preventive breaks that cycle. If your cat hunts, the prey animals they catch are a constant source of reinfection, and more frequent deworming may be necessary.
In multi-cat households, treat all cats at the same time, even those not showing symptoms. Cats can carry worms without any visible signs, and untreated cats will reinfect the ones you’ve already treated. Clean all litter boxes thoroughly during the treatment period, and wash bedding in hot water.