If I am understanding this correctly, your dog is getting overly excited about the food reward she knows will be coming from a training session. My response is too that premise.

This is a common problem a lot of beginner trainers have when training. It comes from not appropriately shaping a behavior with a food lure and then fading the lure at an appropriate time in the training. Food is a very strong incentive to get positive responses from your dog. However, you do not want the dog anticipating the behavior just to get the food. Once the behavior is known and is consistent with the dog, the food reward is too be gradually faded so that the behavior is still performed with or without food.

In your case you have two things working against you. First, the reward is very appealing. Hot dogs are used for a lot of dogs to learn scent discrimination since they are very potent in smell and appeal to the taste buds. Some people prefer chicken because of the fat content in hot dogs. Second, it doesn't sound like you ever faded the food reward.

Fading a food reward (or any incentive reward) is simple. Once the behavior is known and consistent (performed 10 to 15 times in a row for food) then begin to only give the treat every other second time the behavior is done when asked. When the behavior is consistent with the reward every other time for 10 to 15 times then you want to move it to every third time the food reward is given. Of course the verbal reward is given everytime!