8 month old labador

Question
I have switched my 8 month old (27kg.) Labrador to IAMS "adult" dry dog food in the past week. I was giving her 4 cups a day of the large breed puppy kibble before. On the adult bag it says give 2 1/2 cups a day for her size at approx. 27 kg. She is in good shape and not fat now. Should I feed her 2 1/2 cups or 4 cups now of this adult large breed kibble?  

Answer
The early switch to adult chow puts you in good company.  If your puppy was doing well on 4 cups of puppy chow, I don't think 2 1/2 of adult will be enough.  Package recommendations are only a starting point.  It is very important to keep your dog lean, see http://www.longliveyourdog.com/twoplus/RateYourDog.aspx  If your dog is near the ideal body condition, I would continue the 4 cups.  Next time you are in, you might have your vet confirm you judgment of your dog's condition.