Step one: keep her away from any of your own pets. You don't want your pets to get any illnesses she might suffer from as a result of being exposed to all manner of conditions.
Step two: let her eat as much as she wants, but a little at a time. Like, give her a cup, then wait a while and do it again. I could just fill a bowl and leave it out all the time for mine, but she only eats as much as she wants and then stops. Some dogs will eat until they become ill, and you don't want pancreatitis, bloat, or assorted other digestive issues.
Step three: take her to the vet as soon as possible. She's probably got parasites and will need to be vaccinated.

Libby answered on 1/2/13. Helpful? / 0