8 Key Symptoms of Worms in Cats You Shouldn't Ignore (2025)

As dedicated cat parents, we are attuned to every twitch, meow, and purr. But sometimes, subtle changes in our cats' behaviour or appearance can signal an underlying issue we might not immediately recognise. Intestinal parasites are a common but often overlooked health concern that can affect cats of all ages, even those living exclusively indoors. These unwelcome parasites can steal vital nutrients and cause significant discomfort, impacting everything from their digestion to their energy levels.

Recognising the early signs is crucial for swift treatment and ensuring your cat's long-term well-being. It's also important to differentiate these signs from other potential health problems; for example, the various signs of food allergies in cats can sometimes present with similar digestive or skin-related issues.

This guide will walk you through the eight most common symptoms of worms in cats, empowering you with the knowledge to act quickly. We'll explore what each symptom means, which types of worms might be responsible, and what actionable steps you can take to support your feline friend's return to optimal health. Understanding these clinical signs is the first step in getting your cat the care they need.

1. Diarrhoea and Loose Stools: The First Telltale Sign

One of the most immediate and noticeable symptoms of worms in cats is a change in their bowel movements. Persistent diarrhoea or consistently loose stools are classic indicators that something is amiss in your cat's gastrointestinal tract. Intestinal parasites, such as roundworms and hookworms, attach themselves to the intestinal lining, causing significant irritation and inflammation. This disruption interferes with the normal absorption of nutrients and water, resulting in faeces that are watery, poorly formed, or even covered in mucus.

Why It Happens

The presence of worms triggers an inflammatory response in your cat's gut. The body tries to expel the invaders, leading to increased gut motility and fluid secretion. This process rushes food through the digestive system too quickly for proper water absorption, causing diarrhoea. The severity can vary greatly, from a slightly soft stool to severe, watery diarrhoea, depending on the type of worm and the extent of the infestation. While a single episode of loose stool might not be a cause for alarm, recurring or continuous diarrhoea is a strong signal to investigate further.

What to Look For

It's crucial to monitor your cat's litter box habits closely if you suspect an issue. Keep an eye out for these specific signs:

• Consistency Changes: Note if the stool is consistently soft, like pudding, or completely liquid.
• Presence of Mucus: A slimy, jelly-like coating on the faeces often indicates intestinal inflammation.
• Blood in Stool: Fresh, red blood (hematochezia) can signal irritation in the lower intestine or colon, a common result of a worm burden.
• Increased Frequency: Your cat may need to use the litter box more often than usual.

Actionable Tip: If your cat experiences diarrhoea for more than 24 hours, or if it is accompanied by other symptoms like lethargy or vomiting, it is essential to contact your veterinarian. They can perform a faecal examination to accurately diagnose if it's the presence of worms or a more serious problem.

2. Vomiting: A Sign of Severe Irritation

Alongside changes in stool, vomiting is another primary symptom indicating a potential worm infestation in your cat. This reaction happens when intestinal parasites cause significant irritation, inflammation, or even a physical blockage within the gastrointestinal tract. A heavy worm burden can overwhelm your cat's digestive system, leading to the forceful expulsion of stomach contents. The vomit may contain partially digested food, clear liquid, or yellowish bile, and in cases of severe infestation, you might even see live worms.

Why It Happens

Vomiting is the body's defensive mechanism to eject foreign invaders and irritants. Parasites like roundworms can migrate to the stomach, causing nausea and triggering the vomiting reflex. In other cases, a large number of worms can create a blockage in the intestines, preventing food from passing through normally and forcing it back up. This symptom signals a more advanced stage of infestation and should not be ignored, as persistent vomiting can quickly lead to dehydration, electrolyte imbalances, and significant weight loss.

What to Look For

Careful observation is key to helping your veterinarian make an accurate diagnosis. Pay close attention to the specifics of the vomiting episodes:

• Frequency and Timing: Note how often your cat is vomiting and if it happens shortly after eating.
• Vomit Contents: Look for the presence of worms (which can resemble spaghetti), blood (fresh red or dark like coffee grounds), bile, or undigested food.
• Associated Behaviours: Observe if the vomiting is accompanied by lethargy, appetite loss, or abdominal pain. Persistent vomiting can also contribute to poor oral health, which is a separate but related concern. You can discover more about the causes of bad breath in cats and how overall gut health plays a role.

Actionable Tip: If your cat vomits multiple times in a single day, if there is blood in the vomit, or if they appear weak and lethargic, seek immediate veterinary care. If possible and safe to do so, collect a sample of the vomit in a clean container to show your vet, as it can provide crucial diagnostic clues.

3. Weight Loss Despite Normal or Increased Appetite

One of the more perplexing symptoms of worms in cats is unexplained weight loss, especially when your cat’s appetite seems normal or has even increased. This counterintuitive sign often points to an internal parasite problem. Intestinal worms like roundworms, tapeworms, and hookworms are nutrient thieves, surviving by absorbing the essential vitamins, minerals, and calories directly from your cat's digestive tract before your cat can. This parasitic competition for nutrients leads to gradual, yet significant, weight loss over time.

Why It Happens

The mechanism behind this symptom is straightforward malnutrition. Even if you are providing a high-quality, nutrient-dense diet, the worms intercept a substantial portion of it for their own growth and reproduction. Your cat may instinctively try to compensate for this nutritional deficit by eating more, appearing ravenously hungry. However, the increased food intake only serves to better feed the parasites, creating a vicious cycle where your cat eats more but continues to lose body condition. In kittens, this nutrient theft is particularly dangerous as it can severely stunt their growth and development.

What to Look For

Observing your cat's physical condition and behaviour is key to catching this subtle symptom. Pay close attention to these indicators:

• Prominent Spine and Ribs: You may be able to feel or see your cat’s bones more easily when you pet them.
• Voracious Appetite: Notice if your cat is constantly begging for food or finishing their meals much faster than usual.
• Poor Coat Condition: A dull, dry, or matted coat can be a secondary sign of the malnutrition caused by worms.
• Decreased Muscle Mass: A noticeable loss of muscle, particularly over the back and hind legs, is a common sign of weight loss.

Actionable Tip: Get into the habit of weighing your cat monthly at home. You can do this by weighing yourself, then weighing yourself while holding your cat, and calculating the difference. If you notice a consistent downward trend in weight despite a healthy appetite, book a veterinary appointment immediately for a health check.

4. Abdominal Distension (Bloated or Swollen Belly)

A noticeably swollen, rounded, or "pot-bellied" appearance is one of the most classic visual symptoms of worms in cats, especially in kittens. This abdominal distension is not the same as general weight gain from overeating; it often appears disproportionate to the rest of the cat's body, making them look bloated while their spine and ribs may still be felt easily. This swelling is a direct result of a heavy worm burden causing inflammation and physically taking up space within the intestines. This link will show you the different types of worms that can infest cats.

Why It Happens

When a cat, particularly a young one, has a severe infestation of parasites like roundworms, the sheer volume of worms can cause the intestines to swell. The body's inflammatory response to these invaders contributes further to the bloating, as gas and fluid build up in the gastrointestinal tract. In very severe cases, the mass of worms can be so large that it creates a partial blockage, leading to a firm and painful abdomen that requires immediate veterinary attention. This symptom is especially common in kittens as their small bodies cannot handle a heavy worm load.

What to Look For

Distinguishing between a healthy belly and a worm-induced pot belly is key. Pay attention to these specific signs:

• Firmness: Gently feel your cat's abdomen. A belly bloated from worms often feels firm and taut, not soft like a belly full of food or fat.
• Appearance Changes: Take photos to compare your cat's shape over a few days. A worm-related bloat tends to be consistent or worsen over time.
• Pain or Discomfort: Your cat may react negatively or show signs of pain when you touch their swollen stomach.
• Paired Symptoms: Note if the bloating is accompanied by other signs of worms in cats, such as a dull coat, diarrhoea, or lethargy.

Actionable Tip: If you notice your cat's abdomen is swollen, firm, or seems painful to the touch, it is crucial to seek veterinary care promptly. This is especially urgent in kittens. Do not attempt to treat this at home, as a vet needs to diagnose the specific parasite and rule out other serious conditions.

5. Lethargy and Decreased Activity

A noticeable drop in your cat’s usual energy is a significant, yet often overlooked, symptom of worms. If your once-playful feline companion now seems uninterested in toys, sleeps more than usual, or is generally less engaged with its surroundings, an internal parasite problem could be the culprit. This lack of energy, or lethargy, is a direct result of the parasites draining vital resources from your cat's body.

Why It Happens

Intestinal worms are thieves of nutrition. They compete directly with your cat for the nutrients absorbed from food, leading to a state of malnutrition and weakness even with a normal appetite. Furthermore, certain parasites like hookworms feed on blood, which can cause anaemia. This reduction in red blood cells impairs oxygen transport throughout the body, resulting in profound fatigue. The constant intestinal discomfort and inflammation caused by worms also contribute to an overall feeling of being unwell, making your cat less inclined to be active.

What to Look For

Since lethargy can be subtle, it's helpful to establish a baseline for your cat's normal behaviour. Compare their current state to how they were a few months ago, paying attention to specific changes:

• Changes in Playfulness: Your cat shows little to no interest in favourite toys or interactive games.
• Increased Sleeping: They are sleeping more hours per day or are difficult to rouse.
• Reduced Exercise Tolerance: They tire quickly after minimal activity, such as climbing the cat tree or a short chase.
• Social Withdrawal: The cat may hide more often or seek less interaction with family members.

Actionable Tip: If you notice persistent lethargy, especially when combined with other signs like diarrhoea or a poor coat condition, schedule a veterinary visit. Documenting these behavioural changes provides valuable information for your vet. Once treatment is administered, you can expect a gradual but noticeable return to their normal, playful self as their body recovers.

6. Anal Itching or Scooting: A Sign of Irritation

A particularly telling, and often peculiar, symptom of worms in cats is scooting their rear end along the floor. This behaviour, along with excessive licking or biting around the anal area, is a clear sign of intense discomfort and irritation. While several issues can cause this, it's a classic indicator of a tapeworm infestation. As tapeworms mature, they shed segments (proglottids) that migrate out of the anus, causing an irritating, tickling sensation that drives a cat to seek relief by scooting.

Why It Happens

The primary cause of this behaviour is the physical irritation from worm segments. Each segment is filled with eggs and, when passed, can either be expelled with the faeces or actively crawl out of your cat’s anus. This movement creates a significant itch that your cat will try to alleviate by dragging their bottom on carpets, rugs, or other surfaces. The discomfort can be constant, leading to persistent grooming of the area, which may result in hair loss or raw, inflamed skin around their rear end.

What to Look For

Observing your cat's behaviour and environment is key to identifying this symptom. Pay close attention to these specific signs:

• Scooting Behaviour: Note if your cat is frequently dragging its bottom across the floor.
• Excessive Grooming: Look for obsessive licking or chewing directed at the anal region.
• Visible Worm Segments: Check the fur around your cat's anus for small, white segments that look like grains of rice or sesame seeds. These are tapeworm proglottids.
• Evidence in Bedding: Examine your cat’s favourite sleeping spots, bedding, and litter box for these same rice-like segments, which may have fallen off.

Actionable Tip: If you see scooting or find what you suspect are worm segments, try to collect a few in a small container or zip-lock bag. Bringing this sample to your veterinarian can lead to a rapid and accurate diagnosis, ensuring your cat receives the correct treatment for the specific type of parasite.

7. Pale Gums and Mucous Membranes (Anemia)

One of the more alarming symptoms of worms in cats is a noticeable loss of colour in their gums. A healthy cat should have pink, robust-looking gums, similar to the colour of bubble gum. If you notice your cat’s gums appear pale, whitish, or even greyish, it can be a sign of anaemia, a serious condition often linked to a significant intestinal worm burden. Parasites like hookworms are particularly notorious for this, as they latch onto the intestinal wall and feed on your cat’s blood, leading to chronic blood loss.

Why It Happens

Anaemia occurs when there is a deficiency of red blood cells or haemoglobin in the blood, which reduces the blood's ability to carry oxygen to the body's tissues. A heavy infestation of blood-sucking parasites like hookworms can cause enough blood loss to trigger this condition. This is especially dangerous in kittens and senior cats, whose bodies are less able to compensate for the loss. As the red blood cell count drops, the normally pink mucous membranes (gums, inner eyelids, nose) lose their healthy colour. This is a critical warning sign that the parasitic infection is severe and requires immediate veterinary attention.

What to Look For

Regularly checking your cat's gum colour is a simple, non-invasive way to monitor their health. Gently lift your cat’s upper lip to expose the gums and take note of the colour.

• Gum Colour: Look for a change from a healthy pink to a pale pink, white, or greyish hue. You can gently press a finger on the gum; the colour should return almost instantly. A slow return can also indicate poor circulation.
• Concurrent Symptoms: Paleness is often accompanied by profound weakness, lethargy, or a decreased appetite, as the body isn't getting enough oxygen.
• Inner Eyelids: You can also gently check the colour of the inner lining of your cat's eyelids for paleness.
• Overall Demeanour: A cat suffering from anaemia may seem unusually tired, uninterested in play, or may even have difficulty breathing.

Actionable Tip: Any paleness in your cat’s gums is a red flag that warrants an immediate veterinary evaluation. If your cat is also extremely lethargic or collapses, this is a medical emergency. While maintaining good oral health is always important, this symptom points to a systemic issue beyond dental hygiene that needs urgent diagnosis and a targeted deworming treatment.

8. Dull, Poor Quality Coat and Skin Issues

A cat’s coat is often a direct reflection of their internal health, and a sudden decline in its quality can be an external sign of an internal problem. If your cat's once-lustrous fur becomes dull, dry, or unkempt, it may be another of the key symptoms of worms in cats. Intestinal parasites steal vital nutrients directly from your cat's system, leading to malnutrition even with a high-quality diet. This nutrient deficiency means less is available for non-essential functions like maintaining healthy skin and a vibrant coat.

Why It Happens

Healthy fur growth is dependent on an adequate supply of proteins, fats, vitamins, and minerals. When worms like roundworms or tapeworms are present, they compete for these resources in the gut. The cat’s body prioritises essential organ function, leaving the skin and coat undernourished. This nutrient diversion can cause the fur to become brittle and lose its natural sheen. Furthermore, the systemic inflammation caused by a parasitic infection can trigger skin irritation, dryness, and sometimes even secondary skin infections.

What to Look For

Pay close attention to changes in your cat's appearance and grooming habits. An unhealthy coat is more than just a cosmetic issue; it's a window into your cat's overall well-being.

• Dull, Lifeless Fur: The coat may lose its shine and appear dusty or flat.
• Poor Texture: The fur might feel coarse, dry, or greasy to the touch instead of soft and smooth.
• Matted Patches: An unkempt appearance or matting can occur, even if your cat is still grooming.
• Flaky Skin (Dandruff): You may notice white flakes in the fur or on bedding.
• Hair Loss: Patchy hair loss or thinning fur can be a sign of poor health linked to parasites.

Actionable Tip: Take a clear, well-lit photo of your cat’s coat each month to track its condition over time. If you notice a steady decline, especially alongside other symptoms, consult your veterinarian. After successful deworming treatment, supporting their diet with high-quality protein and omega fatty acids can help restore their coat’s health, though it may take 4-8 weeks to see a full recovery.

Cat Worms: 8-Symptom Comparison

Beyond Deworming: Supporting Your Cat's Holistic Health

Navigating the signs of a potential worm infestation is a crucial responsibility for any cat owner. As we've explored, the symptoms of worms in cats can range from the overtly alarming, like vomiting or diarrhoea, to more subtle clues such as a dull coat, lethargy, or unexpected weight loss. Recognising these indicators is the first and most important step toward getting your feline friend the professional veterinary care they need to diagnose and treat the specific parasite responsible. Each symptom, from a bloated belly to pale gums, tells a part of a larger story about your cat's internal health, underscoring the importance of vigilant observation.

However, the journey to wellness doesn't conclude with a dose of dewormer. A parasitic infection takes a significant toll on a cat's body, particularly their gastrointestinal tract and immune system. The recovery phase is just as critical as the treatment itself. This is where proactive, holistic support becomes invaluable, helping to restore balance, build resilience, and prevent future health issues. A comprehensive wellness strategy goes beyond just eliminating the immediate threat; it focuses on rebuilding your cat’s foundational health from the inside out.

Your Action Plan for Post-Worm Recovery

After consulting your vet and administering the prescribed treatment, your focus should shift to long-term health and prevention. This involves creating an environment that minimises the risk of reinfestation and supports your cat’s complete recovery.

Here are your actionable next steps:

• Establish a Strict Prevention Schedule: Work with your veterinarian to establish a regular, year-round deworming and parasite prevention protocol. This is non-negotiable, especially for cats with outdoor access or those in multi-pet households.
• Enhance Environmental Hygiene: Diligent cleaning is key. Regularly wash your cat’s bedding in hot water, thoroughly clean litter trays daily, and wash them out weekly. Also, sanitise food and water bowls. Since fleas are common vectors for tapeworms, implementing a comprehensive flea and tick treatment for your home is a vital step in breaking the parasite life cycle.
• Support Gut and Oral Health: A worm infestation can disrupt the delicate balance of your cat's gut and oral microbiome. Supporting this system is essential for long-term immunity. While focusing on your cat's recovery, consider a simple, non-invasive addition to their routine that promotes overall wellness.

A strong oral microbiome is intrinsically linked to gut health. Complementing your vet's care with a natural, at-home solution can make a significant difference. For busy owners, a product like Purrlys® Premium Dental Probiotics offers a practical way to enhance your cat's health. This odourless and tasteless powder mixes seamlessly into your cat’s wet food, making it a stress-free experience for both of you. It works to rebalance oral bacteria, reduce plaque, and support a healthier gut, all without the struggle of brushing. With a 90-day money-back guarantee, it’s a confident choice for nurturing your cat’s holistic health. By taking these proactive measures, you are giving them the best chance to lead a happy, comfortable, and vibrant life.

Ready to support your cat’s recovery and long-term wellness? Explore how Purrlys can enhance their oral and gut health with a simple, twice-daily sprinkle. Discover the brush-free, fuss-free solution at Purrlys and give your cat the gift of a healthier microbiome.