New cat owner - took in a lost housecat - help about health

A month ago my husband and I took in someone's lost house cat. We've been unable to find its owner, so we've decided to keep it, since the pounds are overflowing. It's our first pet ever!

We took it into the vet 3 weeks ago, and except for worms in his stomach, he got a clean bill of health. But since then, in the past week, he has developed both fleas and ear mites.

We're going into the vet this weekend to get medicine for both. But my question is: why did he only get those now, almost a month after we've had him safely in our house? Are we bringing in diseases from the outside, or did he contract these mites and fleas when he was lost outside for so long, and they've been latent (as eggs or whatever) and are only now developing full force?

Thanks so much for all advice & help!!!

It is possible that your new kitty had the fleas and ear mites when you found him but that they weren't noticeable.

The vet will be able to tell you if it is ear mites for sure and give you medicine for it if it is.

As for the fleas, you will want to make sure that your home is free of fleas or the cat could get fleas again even after he is treated ( I see that Susieq mentioned a flea bomb. I haven't tried one of those myself.). Check out this link about flea control:

http://www.peteducation.com/article....&articleid=590

I would guess that this kitty picked up fleas outside as well as the earmites. As long as you follow the veterianrians instructions with the earmites, they should be gone for good once they are treated.
For the fleas. I don't really like the foggers. They don't get to the places they need to be. Fleas like to hangout near baseboards, bottoms of curtains, couch cushions, etc. One of the products I have found to be most effective is the Knockout area treatment. I know you can find it here http://www.healthypets.com/knocartreat1.html Once you spray it, you let it dry for an hour and it's safe. It kills adults and eggs for 4 months. I would also use a topical on the kitty. Please do not buy over the counter products. They can have some serious toxic effects. I would ask the vet about Advantage or Frontline. Keep kitty on this for at least 3 months in conjunction with treating the house.