The problem is her not the dog.
Dogs need training and education an if they had that behaviour with dish food it seems to me that the owners had never trained the dog.
With 2 years he still is a "juvenile" and the best to do is to look for a professional help with a good dog trainer!

Most people forget the basic of having a dog: teach them who is the boss; and starts to make the dog understand that he can't be possessive with food!
Make a search by "dog behaviour" at the net and I’m sure this people will find valuable information would help them! But they must take an action fast!

Best regards!