My cats have worms

Question
We have four cats.  One of them has roundworms.  All four cats are being treated for worms due to the fact that we are unsure which cat is ill.  Could you tell me how my cats may have caught worms?  They never go outside.  Our vet said it was likely due to them catching a mouse (which they do not/ cannot do), or they may have caught it from a flea.  Both explanations seem odd for my cats.  Do you have any other suggestions?

Thanks,
Mary  

Answer
Hi Mary,

Chances are,  your cats have had roundworms for awhile, and are just now showing up.  It is quite possible that one of your cats (or more) were born with them and spread them to the others through multiple usage of the litter box.  Cat or dogs do not get roundworms from fleas, however, they do get tapeworms from fleas.   The good news is, if your cats are not around other cats and you said you keep them inside, then once you get rid of them, they are gone.   You really should dose them again, though, to make sure.  
I hope this helps.

God Bless,
Becky