As a veterinarian, I understand that your pets are cherished family members who bring joy and companionship into your lives. Protecting their health becomes your top priority, and that often means learning to recognize subtle signs that something might be wrong. While many illnesses present obvious symptoms, common conditions like internal parasites can be sneaky, silently affecting your cat’s health without showing immediate signs. This becomes particularly challenging because cats are masters at hiding discomfort, often masking illness until problems advance significantly. Understanding how to tell if your cat has worms and knowing what to look for can make all the difference in early detection and ensuring your beloved feline stays healthy—missing these signs can lead to serious health issues for your cat.
Summary
Why Internal Parasites Are More Dangerous Than You Think
Internal parasites represent a common concern for cat owners like yourself, ranging from microscopic organisms to visible worms. While they might seem like a minor inconvenience, these parasites significantly impact your cat's overall health and quality of life. Worms feed on your cat's nutrients, cause internal damage, and lead to clinical signs ranging from mild discomfort to severe illness. In kittens, heavy worm burdens can hinder normal growth and development.
Beyond your cat's health, some feline parasites pose genuine risks to human family members. Roundworms can infect humans, potentially causing serious conditions like visceral or ocular larva migrans when their eggs are ingested. Effective parasite control protects your entire household's health—a concept we call "One Health."

Meet the Most Common Culprits: Types of Feline Worms
When I discuss worms in cats with pet owners, we typically encounter two main types: intestinal worms known as roundworms and tapeworms. Adult worms can live for months to years if untreated and are often visible in the feces or around the anus. Intestinal worms are a common concern for pet owners, and cat worms are among the most common intestinal parasites affecting felines. There are different types of worms found in cats, including roundworms, tapeworms, and hookworms, which are the most common intestinal parasites. The most common intestinal parasites in cats are roundworms and tapeworms. These intestinal parasites, also called intestinal worms, are a frequent cause of worm infestation in cats and can significantly affect a cat's health and body.
Liver flukes and the liver fluke are less common but important intestinal parasites that can infect cats. Liver flukes are transmitted through intermediate hosts like snails, frogs, or lizards, and are typically found in warm subtropical areas. Cats worms can cause discomfort and internal inflammation, and various types of worms can infect cats and affect cats' health. Outdoor cats have a higher risk of contracting worms due to exposure to infected prey, infected feces, fleas, and infected soil, but indoor cats are also at risk through indirect contact with contaminated items or other infected pets. Most kittens are infected with worms during nursing, especially through their mother's milk, or when exposed to contaminated environments. Cats can catch worms or contract worms by ingesting parasite eggs, infected feces, or infected soil, or through contact with worm larvae and hookworm larvae, which play a key role in the lifecycle and transmission of infection. Other parasites can also infect cats, and worm infections can be transmitted to humans, making it important to monitor and treat infected cats and any infected cat to prevent the spread of worms. Worms deprive cats of vital nutrients, leading to health issues, and worm infestation is a common condition. The best treatment involves prevention and routine care, including selecting the right worm treatment, deworming cats with deworming medication, and using worming treatments available in various forms such as tablets, liquids, or pastes. Multiple doses may be required to fully eliminate worms, and it is important to begin treatment early, especially in kittens. Veterinarians diagnose worms using a fecal exam, and recognizing cat's symptoms is crucial for timely intervention. Hookworms attach to the intestinal wall using hook like mouthparts, which can cause significant damage. Pet parents should focus on strategies to prevent worms, seek veterinary care to treat worms, and understand the impact of worms on cat's health and cat's body.
Roundworms: the spaghetti-like invaders
Tapeworms: the segmented parasites
Unlike roundworms, tapeworms require an intermediate host, meaning your cat gets them by eating something that carries the parasite. The most common tapeworm in cats, Dipylidium caninum, enters your cat's system when they ingest infected fleas during grooming. Another type, Taenia taeniaeformis, arrives when your cat eats infected prey like birds, rodents, or reptiles. Tapeworms live in your cat's small intestine and shed segments called proglottids, which look like small rice grains and may appear in your cat's feces or around their anus.
Understanding these common types helps you pinpoint potential infection routes and identify the best diagnostic and treatment approaches.

How to Tell If My Cat Has Worms: Recognizing the warning signs
Since cats excel at hiding illness, it's important to watch for the common symptoms of worm infestations. Recognizing subtle changes in their physical appearance, gastrointestinal habits, and behavior becomes crucial for knowing how to tell if your cat has worms.
Physical changes that signal trouble
“Pot-Bellied” Appearance: especially in kittens, a bloated or distended abdomen can signal a heavy worm burden. This occurs because worms occupy space and cause intestinal inflammation within your cat’s body.
Poor Coat Quality: a dull, dry, or unkempt coat can indicate underlying health issues, including parasitic infections, as worms deprive your cat of vital nutrients needed for healthy fur condition.
Pale Gums: when your cat’s gums appear paler than their usual healthy pink color, this might suggest anemia—a condition where your cat lacks enough healthy red blood cells. Severe worm infestations can lead to anemia by consuming your cat’s blood.
Weight Loss Despite Good Appetite: when your cat eats normally or even more than usual but still loses weight, this could indicate parasites are stealing their nutrition.
Digestive system red flags
Vomiting : while occasional vomiting can be normal for cats (especially with hairballs), frequent or chronic vomiting, or vomiting that contains visible worms, strongly indicates a problem requiring immediate veterinary attention.
Diarrhea: any changes in your cat’s stool, such as being softer than usual, increased frequency, loose stools, or containing mucus or blood, can point to intestinal parasites. I recommend noting the duration and appearance of diarrhea for your veterinarian.
Visible Worms or Segments: this often provides the most direct evidence. You might see small, rice-like segments (tapeworm proglottids) near your cat’s anus or in their litter box. Worms or segments can also be found in your cat's stool or cat's poop, and sometimes whole worms may be visible. Some worms are large enough to be seen with the naked eye. Roundworms may appear as long, thin, white “spaghetti-like” worms in vomit or feces.
Scooting or Licking: when your cat frequently drags their rear across the floor or excessively licks around their anus, this could indicate irritation from tapeworm segments.
Behavioral shifts and health changes
- Lethargy or Decreased Activity: cats with parasitic infections may seem unusually tired, less playful, or generally less active than usual. This non-specific illness sign requires investigation.
Changes in Social Interactions or Sleeping Patterns: subtle shifts in how your cat interacts with you or other pets, or noticeable differences in their sleeping habits, can sometimes indicate discomfort or underlying illness.
Coughing : while less common, certain parasites like lungworms can cause respiratory signs such as coughing, since their life cycle involves migration through your cat's lungs. When your cat develops a persistent cough, I recommend mentioning this to your veterinarian.

What to do when you suspect worms: Your action plan
When you observe any of these signs or have a gut feeling something isn’t right, I urge you to contact your veterinarian promptly. If you notice worms in your cat's stool or observe serious symptoms such as pale gums, vomiting, or difficulty breathing, see your vet immediately. Seeking professional help is crucial to properly diagnose worms and treat worms effectively. Resist the urge to self-diagnose or treat your cat with over-the-counter dewormers, since different worms require different medications, and improper treatment can prove ineffective or even harmful.
Preparing for your veterinary visit
When you contact your veterinarian, be prepared to provide detailed history. Your veterinarian will likely ask about your cat's diet, including food brand and type, treats, table scraps, or supplements. They'll also want to know about their environment and habits, such as whether they stay indoor-only or have outdoor access, hunting behavior, and other household pets. Be ready to discuss any previous or current medications and provide clear descriptions of all clinical signs you've observed, including when they started and how they've progressed.
The diagnostic process
When possible, bring a fresh stool sample to your appointment. A fecal examination, where we analyze the sample under a microscope, often serves as the first step to identify specific worm eggs or larvae, guiding appropriate treatment. Veterinarians use a fecal exam to diagnose worms by identifying parasite eggs and worm larvae present in the sample. This targeted approach ensures your cat receives the most effective and safe medication for their specific condition, with deworming medication prescribed based on the type of worm identified. Your veterinarian may also recommend basic blood work and urinalysis to check for other underlying health issues.

Prevention: Your best defense against parasites
Preventing parasitic infections proves far easier than treating them. The best treatment for worms is prevention, which includes routine deworming cats, maintaining good hygiene, and regular veterinary checkups. Pet parents should know that worming treatments are available in various forms—liquids, pastes, granules, and tablets—and may require multiple doses to fully eliminate worms and prevent re-infestation. Deworming cats is a routine preventive measure that not only helps prevent worms but also protects against other parasites. Outdoor cats are at higher risk of infection due to exposure to infected soil, infected feces, and infested environments, but indoor cats can also be exposed through contaminated items or contact with infected soil or feces. Regular veterinary visits are essential for preventive healthcare and early disease detection. During these visits, your veterinarian can recommend appropriate deworming schedules based on your cat’s lifestyle and risk factors.
Consistent flea control also becomes critical, since fleas commonly carry tapeworms. I encourage you to discuss the best flea prevention products with your veterinarian to ensure year-round protection. Additionally, maintain good litter box hygiene by scooping daily and cleaning litter boxes regularly to reduce re-infection risk and help prevent worms.
Your veterinarian serves as your most valuable partner in your cat’s health journey. By being observant, communicating openly, and adhering to professional recommendations, you empower them to provide the best possible care for your feline companion.

Final thoughts: Protecting your feline family member
The information in this article is based on the following scientific publications:
- Elliott, J., & Grauer, G. (Eds.). (2006-2007). BSAVA Manual of Canine and Feline Nephrology and Urology (2nd ed.). BSAVA Publications.
- Villiers, E., & Blackwood, L. (Eds.). (2005). BSAVA Manual of Canine and Feline Clinical Pathology (2nd ed.). BSAVA Publications, Gloucester
- Horwitz, D. F., & Mills, D. S. (Eds.). (2009). BSAVA Manual of Canine and Feline Behavioural Medicine (2nd ed.). BSAVA Publications, Gloucester
- Harvey, A., & Tasker, S. (Eds.). BSAVA Manual of Feline Practice: A Foundation Manual. BSAVA Publications
- Rendle, M., & Hinde-Megarity, J. (Eds.). (2022). BSAVA Manual of Practical Veterinary Welfare (1st ed.). BSAVA Publications.
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