Was he a stray? or underfed? Most dogs that have had to fight for their food will become possessive of it. Your best bet is to feed them in their crates or in seperate rooms. Train Sal to park (go to a specified area) until Roxy has finished eating. Always pick up the dishes once dinner time is done.

Just a word of warning - if either is food possessive, make sure you never leave bones or rawhide chews out. I have seen a great many major fights over these items.

Good Luck - and welcome to Pet Talk