The symptoms differ in every kind of parasitic worm, but some can be common to most of the infestations. If any of the following symptoms are visible in your cat, take them for a visit to the vet to know the exact problem and remedy. Diarrhea Vomiting Bloody stool Constipation Weight loss Bloating/ round abdomen Coughing Visible worms in stool Visible worms near the anus