My 9 month old female pit bull has rapidly lost weight. I checked her stool and there is no sign of worms. Also I was wondering if chesnut's would make her sick. She isn't vomiting she seems a little weak and she's still eating..

You could check the sticky at https://www.askmehelpdesk.com/dogs/information-articles-our-dogs-expert-labman-53153.html#post254171
But this sounds like a clear case of a sick dog needing the vet. I don't know about chestnuts, but almonds are bad. Be sure and tell the vet about the chestnuts.

I agree with labman. Whenever a dog is losing weight rapidly and there isn't any easy explanation for it, it is time for a vet check. Please post back and let us know how she is doing. I am curious about the chestnuts. I do know that Macadamia nuts are also bad for dogs. Unless you fed her more than a couple, this shouldn't cause a serious health issue.

I say Go to the vet and check it out.