If you notice chronic diarrhea, this may indicate the presence of roundworms or hookworms in your cat. Be cautious, both worms may be transmitted to humans.
Excessive vomiting points to parasites such as: roundworms or stomach worms. Stomach worms are rare, but still exist in stray cats and may be transmitted to house cats.
3. Constant Hunger
Roundworms and tapeworms cause constant hunger. The worms eat the food the cat ingests, so the cat will not feel full and is hungry all the time. This may also result in weight loss, as the nutrients don't get into the cat's system.
4. Lack of Appetite
While other worms cause excessive hunger, the stomach worms cause a lack of appetite.
A less noticeable symptom, lethargy in cats may indicate a number of health issues; lack of energy is also a symptom of roundworms and stomach worms.
If a cat hosts hookworms, these will feed on the animal's blood, and will cause anemia. Kittens with hookworms are at risk, as this parasite may kill the host.
7. Worms in the Stool
Worms are often eliminated in the stool of the cat, but this does not mean that the cat is cured; there might be more parasites. Segments of tapeworms and roundworms can are visible in the cat's stool. The tapeworm segments are light in color and resemble sesame seeds. Roundworms have a spaghetti-like look and may be 2 to 4 inches long. The stool may contain stomach worm eggs when the cat hosts this parasite.
8. Blood in the Stool
Hookworms will often cause blood in the stool of the cat and this symptom is usually accompanied by severe abdominal pain.
However, in some cases, despite the lack of symptoms, parasites are present. Pay special attention to the heartworm: this is a silent killer; it has no clear symptoms in the early stages, but may be fatal. Cats can get infected with these parasites from other animals, by ingesting fleas or even from a mosquito bite, so it is impossible to avoid the infestation.
What you can do is to go for a regular check-up and get suitable treatment from your vet. Blood tests and stool samples can give a clear diagnostic.
Many veterinarians agree to de-worming cats twice a month even if they don't have parasites. A pill can generally solve the problem, but make sure your pet ingests the pill.