My cat vomited, has watery eyes. Could she have worms? How do vets diagnose?

Hi, thanks for using Petco Pet Education Center, formerly Petcoach!

Most intestinal parasites are passed fecal-orally (meaning the animal would have to eat infected stool) or from ingestion a mouse or a flea. Signs of intestinal parasites are weight loss, diarrhea and possibly vomiting or decreased appetite. The only way to diagnose worms to to physically see the adults or have a stool sample checked to see the eggs microscopically. Sometimes Vet will just treat for them, especially if they are suspicious or the cats go outdoors. You can always see if your Vet would treat with out a stool sample.

I have never heard of any parasite causing excessive tearing. That is most commonly a viral upper respiratory tract infection or allergies. Sometimes cats just vomit. Other causes of vomiting are: intestinal parasites, viral or bacterial infections, ate something gross, ate something that is stuck, pancreatitis, intestinal disease.

I hope this helps!