For the  most part, you should not need custom dog training devices.  That said, if you are training your dog for a special purpose, you may need additional types of equipment.   On the other hand, if you are training a dog for various kinds of competition, you may need various training aides.  As an example, if you are training your dog for hunting purposes, or athletic events, you will need a number of different props.  In some cases, you may also want to purchase electronic devices that will help you monitor the activities of your dog, as well as train them more efficiently.