food ???

hello everyone ,
luca my 19 week old pup is on a dry food called advanced nutrition , my brother has a sbt crosss at 11 months and is also on the same food . when together on a weekend luca seems to eat a considerable amount more food when with my brothers dog , why is this / and any advice on how to get luca to eat more without other dog (sky) ?
many thanks

It could be that your dog will have more exercise when with the other dog therefore will have more of an appetite. He maybe needs a bit more of a walk. Be careful that you leave time between exercise and feeding though. Try some mental stimulation too by way of games where your dog has to work things out, hide food in toys, see link

http://www.amazon.co.uk/Labyrinth-Snacky-Natural-Rubber-Ball/dp/B00121XPS0/ref=sr_1_60?s=pet-supplies&ie=UTF8&qid=1322587864&sr=1-60

It may also be that she is eating more because he is there and she wants to make sure he doesn't get it. Also, it could be she is getting more exercise playing with him so much. I wouldn't worry as long as she is healthy.