If your dog eats vegetables (mine does) I suggest giving them carrots as a treat. My puppy likes them and I use it when I train him. I sometimes give him a little peanut butter too.
You can also boil chicken liver or bake it for treats. Chicken liver is ridiculously cheap where I live, it costs $1 for a kg which goes a long way.
Good luck with the training!

I sometimes give him a little peanut butter too

Dogs love peanut butter, but be careful, some dogs, just like humans, can actually by allergic to peanuts, so if you are planing on giving them peanut butter start with a tiny amount first and be on the lookout for any adverse or allergic reactions. Increase the size if nothing happens, but not too much, because peanut butter is a very calorie dense product and they love it so much that you could end up with a very fat dog.

As far as healthy treats go, I cut up some carrots and apples for my dog. It is an affordable way and a great source of vitamins. In the summer, we even gave him watermelon, and blueberries. He loves them.

Occasionally, I found already made treats in the store which contained only two ingredients, at a very reasonable price and I stocked up on these.

The best treats for a dog are fats and meat. Dogs were created carnivores and giving them raw meat will make their taste buds scintillate. However, you should give them meat individually as dogs are very protective when it comes to food in order to avert nasty quarrels. Dogs also like fatty foods. A favourite vegetable for my pet is the avocado.

You can bake your own peanut butter treats at home. I add vegetables like carrots and peas into my mix. You might be able to buy some pea flour so that your dog can digest them easily. I hope your dogs enjoy their new treats.

We give our dogs puppy kibbles not only because they're rich in protein and carbohydrates, but our dogs love them because they're more chewable and easier to digest than kibbles designed for adult dogs. We also feed our dog a combination of meat and fish to keep them active all the time. We have energetic dogs so the more protein and carbohydrates in their diet, the more advantageous it is for their health.

As others have been saying, the best treats are natural ones that would be in a wild dog's diet -- meat and roughage. Usually when I treat my dogs, it's with some kind of chopped up chicken (cooked) or peas. Peas work really well because you can freeze them and it brings out some sweetness. Since they're tiny, you can use them during training too.

Some people like to make their own dog treats. You can easily do this by blending together some peanut butter, chopped fruit, peas, carrots and some gluten-free flour (like garbanzo bean) and make cookies just as you would for people. It's also pretty cost effective in the long run.

I am a big fan of any "one-ingredient" treats, like the freeze-dried pieces of chicken or strips of beef and turkey. I am wary of treats with a ton of ingredients in them, especially with added color or artificial flavors, since I'm not sure how the dogs' stomachs will respond to it. We also don't always know the long-lasting effects of some of those artificial flavors. When the treats only contain the one ingredient, it's pretty easy to gauge how healthy it is.

I've never made by own treats (usually buy bags from Amazon or a local pet store), but I like some of the recipes above. I might have to give it a shot. Anyone have recipes for treats that can be made in bulk and preserved for a while in the fridge/freezer?

Another vote for carrots - my dogs really love them, and if you want an instant ready to go snack that doesn't go bad easily, you can just pick up the already peeled small ones to dole out on a walk or elsewhere. Otherwise I make liver biscuits that I keep in small Ziploc's in the freezer. Sometimes I cook some chicken or a sweet potato that I've diced up and keep it in the fridge for snacks while we are inside. There have been so many repeated recalls of commercial "treats" that I haven't used any for quite a few years now.

My dog loves peanut butter and we give him that as a healthy treat. We also give him some tuna or any canned salmon. He likes the fish and the fish oils help to give him a shiny coat.

I've always stuck the original Milk Bone and had good results. The vet gives my pup a clean bill of health every appointment, and I probably give him milk bones a couple times per week. Jake has a healthy weight and I'll continue feeding the MilkBones to him in the coming years.

Some unseasoned chicken, carrots and cucumber are the ones our dog likes the best out of all of the healthy choices. Those are not so bad for the dog since they don't have any additional fat and other bad things that could be harmful for the dog. With treats like those our dog has maintained her ideal weight, even when she's after everything that's edible, haha!

I love the fact that we live in the age where we have healthy treats. I know that they may not be as healthy as they claim or some people think they are, and they are certainly not just the answer for having a healthy pet, but I am willing to be a little willfully ignorant and utilize them anyways. I tend to stick to the originals, but I do think that they are much better than previous products.