As cat owners, we tend to notice the little things and the unusual meow, a change in appetite, or a cat who suddenly isn't quite as playful. But when it comes to intestinal parasites, the warning signs can be surprisingly easy to miss.
Worms are common in cats, including those that live entirely indoors. If left untreated, they can rob your cat of important nutrients, irritate the digestive system, and affect their energy and overall well-being.
Some symptoms can also look like other health problems. Digestive upset and skin changes, for example, may resemble the signs of food allergies in cats. That is why it is always best to have your vet confirm the cause rather than trying to diagnose worms at home.
Below are eight common symptoms of worms in cats, what may be causing them, and what to do if you notice them.
1. Diarrhoea and Loose Stools
One of the first things you may notice is a change in your cat's bowel movements. Ongoing diarrhoea or consistently loose stools can be a sign that something is irritating the gut.
Roundworms and hookworms can affect the intestinal lining and interfere with the absorption of water and nutrients. As a result, your cat's stools may become soft, watery, poorly formed, or coated in mucus.
What to look for
• A change in consistency: Stools may be unusually soft, pudding-like, or completely liquid.
• Mucus: A slimy or jelly-like coating can point to irritation in the intestines.
• Blood in the stool: Fresh red blood may appear when the lower intestine is irritated.
• More litter tray visits: Your cat may need to go more often than usual.
One loose stool does not always mean worms. However, if the diarrhoea continues for more than 24 hours—or your cat is also vomiting, lethargic, or not eating—contact your vet. A faecal test can help confirm whether parasites are responsible.
2. Vomiting
Worms can sometimes cause enough irritation in the digestive tract to make a cat vomit. In more severe cases, roundworms may move into the stomach, and you might even see worms in the vomit. They are often described as looking like pieces of spaghetti.
A heavy infestation can also interfere with the normal movement of food through the digestive system. Because repeated vomiting can quickly lead to dehydration, it should never be ignored.
What to look for
• How often it happens: Note whether your cat vomits once or several times, and whether it happens after eating.
• What is in the vomit: Check for visible worms, blood, bile, or undigested food. Digested blood may look dark, similar to coffee grounds.
• Other changes: Loss of appetite, lethargy, or signs of abdominal pain make the situation more urgent.
Repeated vomiting may also contribute to unpleasant breath. You can read more about the causes of bad breath in cats, including the possible connection with digestive health.
If your cat vomits several times in one day, seems weak, or has blood in the vomit, seek veterinary care straight away. If you can collect a small sample safely, bring it with you—it may help your vet reach a diagnosis.
3. Weight Loss Despite a Normal or Increased Appetite
This symptom often takes owners by surprise. Your cat may be eating normally, or even seem hungrier than usual, yet continue to lose weight.
Parasites such as roundworms, tapeworms, and hookworms can take nutrients from your cat's digestive tract before the body has a chance to use them. Your cat may try to compensate by eating more, but the weight loss can continue. This is especially worrying in kittens because poor nutrient absorption can affect healthy growth and development.
What to look for
• More noticeable ribs or spine: Their bones may become easier to see or feel.
• An unusually strong appetite: Your cat may beg constantly or finish meals much faster than before.
• A dull or untidy coat: Poor nutrition often shows up in the condition of the fur.
• Loss of muscle: This can be particularly noticeable along the back and hind legs.
It helps to weigh your cat once a month. You can weigh yourself first, then weigh yourself while holding your cat and subtract the difference. If their weight keeps dropping despite a good appetite, arrange a veterinary appointment.
4. A Bloated or Swollen Belly
A rounded, pot-bellied appearance is one of the better-known signs of worms, particularly in kittens. Unlike a cat who has simply eaten a big meal, a cat with a heavy worm burden may have a noticeably swollen abdomen while the rest of the body remains thin.
This can happen when parasites cause inflammation and take up space in the intestines. Gas and fluid may also build up. In severe cases, a large number of worms can contribute to a partial blockage. You can learn more about the different types of worms that can affect cats.
What to look for
• A firm or tight belly: Worm-related swelling may feel different from a soft, full stomach.
• Swelling that does not settle: Take a photo and compare the abdomen over several days.
• Pain or sensitivity: Your cat may flinch, tense up, or resist being touched.
• Other symptoms: Diarrhoea, lethargy, weight loss, or a dull coat can add to the concern.
A swollen, firm, or painful abdomen needs prompt veterinary attention, especially in a kitten. Do not try to treat it without professional advice, as other serious conditions can cause a similar appearance.
5. Lethargy and Less Interest in Play
You know your cat's normal personality better than anyone. If a usually lively cat starts sleeping more, hiding, or showing little interest in play, something may be wrong.
Worms can drain the nutrients your cat needs for energy. Hookworms are particularly concerning because they feed on blood and can contribute to anaemia. With fewer healthy red blood cells carrying oxygen around the body, your cat may feel genuinely weak and tired. Ongoing digestive discomfort can also make them quieter than usual.
What to look for
• Less interest in toys or games: Favourite activities no longer get much of a response.
• More sleep than usual: Your cat may spend longer resting or be harder to rouse.
• Tiring quickly: A short play session or climb may wear them out.
• Withdrawing: They may hide more or seek less interaction with people and other pets.
If the change lasts or appears alongside diarrhoea, weight loss, vomiting, or a poor coat, book a vet visit. Write down what you have noticed and when it began; those details can be useful during the examination.
6. Anal Itching or Scooting
Scooting is when a cat drags their bottom across the floor. It usually means the area around the anus is itchy or uncomfortable, and tapeworm segments are one possible cause.
As tapeworms mature, they shed small segments containing eggs. These may pass in the faeces or move out through the anus, creating irritation. Your cat may scoot, lick, or bite at the area in an attempt to get some relief.
What to look for
• Scooting: Repeatedly dragging the bottom across floors, rugs, or carpets.
• Excessive grooming: Frequent licking or chewing around the rear end.
• Rice-like pieces: Small white segments around the anus may resemble grains of rice or sesame seeds.
• Segments in bedding or the litter tray: Check the places where your cat sleeps and toilets.
If you find what looks like a worm segment, place it in a small clean container or sealed bag and take it to your vet. This can make identifying the parasite much easier. Scooting can have other causes too, so a proper examination is important.
7. Pale Gums or Other Signs of Anaemia
Healthy cat gums are usually pink. If your cat's gums look unusually pale, white, or grey, they may be anaemic—and that needs urgent veterinary attention.
Hookworms attach to the intestinal wall and feed on blood. In a heavy infestation, the ongoing blood loss can reduce the number of red blood cells available to carry oxygen through the body. Kittens and senior cats may be especially vulnerable.
What to look for
• Pale gums: Instead of their usual pink colour, the gums may look very light, white, or greyish.
• Weakness or extreme tiredness: Low oxygen levels can leave your cat exhausted.
• Pale inner eyelids: The lining inside the eyelid may also lose its normal colour.
• Breathing difficulty or collapse: These are emergency warning signs.
If your cat has pale gums, contact a vet immediately. If they are struggling to breathe, extremely weak, or have collapsed, treat it as an emergency. They may need blood tests and urgent treatment rather than deworming alone.
8. A Dull Coat or Skin Changes
A cat's coat often gives clues about their overall health. Fur that was once glossy and soft may become dull, dry, coarse, or difficult to keep tidy when the body is not receiving enough nutrition.
Roundworms and tapeworms can compete for nutrients in the gut. The body naturally prioritises essential organs, which means the skin and coat may receive less of what they need. Inflammation and reduced grooming due to illness can make the change even more noticeable.
What to look for
• Dull fur: The coat may lose its shine and appear flat or dusty.
• A different texture: Fur may feel dry, rough, greasy, or brittle.
• Matted areas: The coat can start looking untidy even when your cat is still grooming.
• Flaky skin: You may notice white flakes in the fur or on bedding.
• Hair thinning: Patchy hair loss can be a sign that your cat's overall health needs attention.
Taking a monthly photo in similar lighting can make gradual coat changes easier to spot. If the coat continues to decline, especially alongside other symptoms, speak with your vet. Once the underlying problem has been treated, good nutrition—including quality protein and appropriate fatty acids—can support recovery. A full improvement in the coat may take several weeks.
Cat Worm Symptoms at a Glance
Diarrhoea or loose stools
This is usually easy to notice when cleaning the litter tray. Monitor your cat and collect a stool sample if your vet requests one. Contact your vet if the diarrhoea lasts longer than 24 hours or appears with other symptoms.
Vomiting
Note how often your cat vomits and what the vomit contains. Repeated vomiting can indicate significant irritation or, in rare cases, a blockage. Seek urgent care if you notice blood, weakness, or repeated vomiting.
Weight loss despite a normal appetite
Weight loss may happen gradually, so regular weighing can help you catch it early. Continued weight loss may point to poor nutrient absorption or malnutrition and should be assessed by a vet.
Bloated abdomen
A swollen belly is often noticeable, particularly in kittens. It can be linked to a heavy parasite burden, but other conditions can cause it too. Arrange prompt veterinary care if the abdomen feels firm or painful.
Lethargy
Changes in energy can be easier to recognise when you know your cat’s usual behaviour. Persistent tiredness may be related to nutrient loss, discomfort, or anaemia.
Scooting or anal itching
Scooting is usually easy to spot. Check the area for small, rice-like segments and collect a sample if possible. Remember that anal irritation can also have causes unrelated to worms.
Pale gums
Pale gums can be a sign of anaemia and should be treated as urgent. Contact your vet immediately, especially if your cat is weak or having difficulty breathing.
Dull coat or skin changes
Coat changes usually develop gradually. If your cat’s fur continues to worsen or the change appears alongside other symptoms, arrange a veterinary assessment.
Beyond Deworming: Helping Your Cat Recover
Noticing the symptoms of worms in cats early can make a real difference. Some signs, such as vomiting or scooting, are difficult to miss. Others—like gradual weight loss or a coat that has lost its shine—may only become obvious over time.
The first step is always a proper diagnosis and treatment plan from your vet. Different parasites require different treatments, and symptoms that look like worms can sometimes have another cause.
Once treatment has started, your cat may also need time and support to recover. A parasitic infection can take a toll on digestion, nutrition, and overall wellbeing, so the care you provide at home matters too.
A simple post-treatment care plan
• Follow a prevention schedule: Ask your vet about a regular, year-round parasite prevention routine that suits your cat. This is particularly important for outdoor cats and homes with several pets.
• Keep their environment clean: Scoop the litter tray daily, wash it thoroughly each week, clean food and water bowls, and wash bedding in hot water. Fleas can carry tapeworms, so a comprehensive flea and tick treatment for your home may also be part of breaking the parasite life cycle.
• Support general gut and oral health: Good nutrition, fresh water, and a consistent feeding routine can help your cat as they return to normal. Ask your vet before adding supplements during recovery, particularly if your cat is taking medication or has another health condition.
Purrlys® Dental Probiotics can be added to your cat's regular routine to support oral and gut health. The odourless, tasteless powder is designed to be mixed into wet food—one scoop, twice daily—so there is no brushing or wrestling involved.
With consistent use, you may notice fresher breath after around two weeks, while changes in plaque and gum health may take four to six weeks. Results can vary from cat to cat. Purrlys® Dental Probiotics also comes with a 90-day, 100% money-back guarantee.
Purrlys® is not a treatment for worms and should not replace veterinary care or prescribed deworming medication. If your cat is unwell or you are unsure whether the product is suitable for them, speak with your vet first.
Ready to support your cat's everyday oral and gut health? Discover Purrlys® Dental Probiotics and make caring for their microbiome a simple part of mealtime.