5 Silent Signs Your Cat Might Have Worms — And How to Spot Them Early

They groom constantly, nap endlessly, and often hide pain well — which is why internal parasites in cats can go undetected for weeks or even months. But according to a recent veterinary report, worms are far more common in domestic cats than many owners realize — and the symptoms can be deceptively subtle.

Whether your cat lives indoors or roams outside, no feline is entirely immune to parasitic infections. Here are five key signs your cat may be harboring unwanted guests — and how to respond before the problem escalates.

1. Sudden Weight Loss

If your cat is eating normally (or even more than usual) but still losing weight, worms could be the culprit. Intestinal parasites steal nutrients from food as it’s digested, leaving the host malnourished despite adequate intake.

This symptom is often overlooked in overweight cats, where gradual muscle loss is masked by body fat. Keep an eye on your cat’s body condition and use a hands-on check for bony ribs or a shrinking waistline.

2. Changes in Appetite

Worms can either suppress or increase appetite. Some cats may lose interest in food entirely, while others begin eating obsessively. Both behaviors may be linked to digestive discomfort, nausea, or metabolic interference caused by parasites.

If food habits change without an obvious explanation, a vet visit — and a fecal test — may be warranted.

3. Vomiting or Diarrhea

Frequent vomiting, especially with visible worms, is a clear red flag. Diarrhea — whether chronic or intermittent — may also occur as the parasites irritate the gastrointestinal lining.

Tapeworm segments may appear like small white grains near the tail or in feces, while roundworms may resemble spaghetti-like strands. Any visible parasites should prompt immediate treatment.

4. Itching, Scooting, or Excessive Grooming

Some worms irritate the anal area, causing cats to lick or “scoot” across the floor for relief. Others lead to generalized itching or fur pulling, particularly around the hindquarters or belly.

While these behaviors can also point to fleas or allergies, parasites are often overlooked — and can co-exist with other skin conditions.

5. A Dull Coat and Low Energy

One of the most common long-term effects of worm infestation is poor coat condition. The fur may appear greasy, patchy, or dull. In addition, cats may seem lethargic, withdrawn, or less inclined to play.

This systemic impact comes from nutrient loss, dehydration, and internal inflammation caused by the worms. Left untreated, the damage can become permanent.

Prevention and Treatment

Regular deworming — especially for outdoor cats — is essential. Most vets recommend a treatment every 3 to 6 months, depending on lifestyle and risk. Indoor cats may require less frequent deworming but still benefit from routine checks.

Always use vet-approved medications; over-the-counter or homemade remedies can be ineffective or dangerous. A fecal test will help determine the type of parasite and guide proper treatment.

Final Reminder: Know the Subtle Signals

Cats are masters of hiding discomfort — but the signs of a worm infestation are there if you know where to look. From odd grooming habits to digestive shifts, these subtle clues can help you catch a problem before it becomes severe.

And when it comes to your cat’s health, a little vigilance goes a long way — especially against foes you can’t see.