Worms and cats

Question
My husband & I recently brought in a stray cat during the cold weather.  We don't know if it is a male or female as it has a lot of fur.  It's been with us for a few weeks.  Lately, I've noticed a few hairballs.  Tonight, in its vomit, I think there was a worm.  It is white, rounded (not flat) with tapered ends.  If it was a worm, it wasn't alive.  Can it be a worm or is it just something that looks like a worm?  We've let the cat into our house (its been sleeping in our heated garage) on numerous occasions and we have an indoor cat.  Can our indoor cat be infected?  The stray is very thin - I thought from being a stray.  However, could it be due to worms?

Answer
It sounds like a roundworm and you should take the cat to the veterinarian for a check up and deworming.  Not only have you put your indoor cat at risk for intestinal parasites, but you also have put your cat at risk for Feline Leukemia and FIV and other infectious diseases.  It is very important to have a blood test for these 2 viruses as well as a veterinarian examination, vaccinations and a fecal analysis (checking for other parasites) to ensure this stray is healthy ieally BEFORE introducing to another cat.