Dogs don't have to eat meat to be healthy and happy - and vegetarian dog treats will be a nice change for your four legged friend.
Most dogs love raw fruit and vegetables - pieces of apples and carrot, broccoli and cheese are usually welcomed - Luigi is a big fan of peas (especially if they are straight from the pod!). Try these healthy treats for dogs for more ideas.
Research by Animal Diversity shows that feral dogs will choose to eat fruit as part of their diet. And this page says that dogs will healthily digest a variety of foods, including vegetables and grains, and can consume a large proportion of these in their diet.
If you are a vegetarian then you will have a good idea of what to feed your pooch as treats. Here is an excellent example from The Complete Holistic Dog Book
I'm a vegetarian. So is Savannah. Since Savannah is a Great Dane, I cook in big batches. I'll soak black beans or garbanzos overnigt and let them simmer a few hours the next morning. I toss lentils, mung, or other small beans right in with my rice and cook both in the same pot. Split peas (her favorite!) mean soup for both of us in about an hour's cooking time. As an alternative to rice, I use potatoes or corn polenta, and often add raw rolled barley after cooking.
Meat substitute foods work well - vegetarian hot dogs and burgers make great doggy treats. Just watch out for those dangerous dog treats that will make your pet ill. You can also find vegetarian dog bones and chews.
It is also fun and easy to make your own homemade treats - and this gives you more control over what your pet is eating. Pumpkin for dogs is a great example. This dog superfood will fill your dog up - without piling on the pounds!
Frozen dog treats are also mostly made with vegetarian ingredients - and are a great way to get your pet to eat fruit in his treats. If you are looking for a way to make flour-less recipes, then these are a great place to start. Keep the portions small (ice cue trays are perfect) so your dog doesn't get too chilled.