Gluten and wheat-free treats for the show ring
smoked ham (or other cold meat if he likes it)
Cheese - any hard smelly cheese will do (cheddar is good)
Dried meat jerky
Dried Liver
You can make your own liver cake and use gluten free flour - the recipe should be on this site if you do a search.
Burns and James Welbeloved are wheat free and gluten free complete foods for dogs. They will send you samples if you contact them through their web sites.
http://www.burns-pet-nutrition.co.uk/products.html#adulthttp://www.wellbeloved.co.uk/Hope this helps
Dill