If we want to succeed with positive reinforcement training we need to make sure that the reinforcers we use actually reinforce the dog. Remember, that it is the dog who decided whether something is reinforcing for him/her. Just to make sure that we are on the same page. A reinforcer is everything that makes a behavior repeat itself or increase in frequency. In order for a reinforcer to increase the frequency of a behavior, it needs to be rewarding to the dog.
Food is usually a great reinforcer for dogs since it is such a basic and innate need. But food is a general term for various kinds of smells and tastes. The dog’s kibble may be enough to get him/her to sit in a home environment, but it is unlikely to get the dog to heel in a crowded environment. Choose your foods wisely, test different types of foods, make a list of the foods your dog loves the most and make sure you save the really good foods for really hard exercises such as coming when called in a very distracting environment.
Remember, that toys and games can be just (if not more) as reinforcing as food in certain situations. Many dogs will find a game of tug, or chasing a flying disc more reinforcing then food in certain situations. The environment itself is also filled with reinforcers: The already marked tree, the smells in the bushes, the pigeons, the cats, the cockroaches, etc. You can use all those to your advantage if you just pay attention and observe your dog wishes – for example if your dog wants to pull to a marked tree, teach him that if the leash is loose he will get there and if it tight, he won’t.
So experiment with your dog and try various foods, toys, and environmental rewards to see what works best for you. The longer the list of reinforcers you have, the better trainer you will be.