When you first start to train a cadaver dog, you will want to have a good amount of basic obedience training already accomplished. Your dog needs to know how to behave on a leash. He needs to know how to sit, especially if that is the "alert" that you will want him to use, or to "down" (for the same reason). Some handlers prefer that their dog do a bark alert at the indication of cadaver, others prefer that their dog will scratch at the cadaver. If this is the case, your dog will need to know the verbal commands to perform these behaviors. Your dog also needs to know how to follow directional signals to a certain degree, in other words when you say to your dog "check it out" and indicate to him an area that you want him to search, he should already know what those words mean.
It is best to start a Cadaver Dog who already has attended at least one obedience class, who is bonded to you well enough that the majority of the time he will focus on what you want him to perform. A good test for this thing called "focus", (which is a highly important aspect of a good search dog) is to try this little trick. Say your dogs' name, when he is distracted. Do this often. Say your dog's name, when he is not distracted. Do this often too! If you can count on his looking at you within 3 seconds after you say his name, ninety percent of the time, then you are ready to advance to training for cadaver.
Depending on the breed, most dogs are not ready for this kind of focus until they are past the age of six months. In addition, some dogs will appear to be quite focused but at about 8 months old it all goes out the door and they become like wild adolescents and never "listen" to a thing you say. If that happens, cut back on the training exercises and concentrate on obedience and skill work, mixed with a lot of socialization and long walks.
Do not start your dog on cadaver until you also have a reward for him that lets him know that he is absolutely the most wonderful dog in the world and that you are very very happy with him. This must be a reward which really lets him know, in no uncertain terms, that he has done something great. You need to know your dog well enough to know what it is that will "turn him on" and be ready to give him that special thing. Whether it be praise and affection or a special toy or a food treat, have it ready.
Then get out your cadaver. For this first introduction, you will need only one cadaver scent article. This can be tissue, blood or teeth. Bone and Hair are not usually sufficient in the very beginning. Lay out several articles on the floor, or outdoors in the grass, wherever you want to start. Use common everyday articles, things that are not highly interesting to the dog and perhaps with which he is not familiar. These can be any household item, as long as it is not a special toy that your dog loves, or your own articles of clothing. Examples are; a coffee can, a hammer, a plastic spatula, a kitchen pot, you get the idea. You should scatter about six or seven of these articles around in a 50 foot square area. Amongst them have ONE cadaver item, in a glass salt shaker with the lid open so that the scent will come out through the holes. Never handle cadaver with your bare hands, you should have prepared this cadaver and placed it in the shaker and handled the shaker with plastic gloves!!
Then allow your dog, on lead or loose, to wander into this area of mixed articles. Chances are he will sniff at a few of these things and especially the chances are good that he will sniff at the cadaver. The instant he touches the cadaver, reward him with hearty praise and give him his treat. Do this several times, in different locations and using different items. Gradually add in more than one cadaver scent. Only reward him for sniffing or touching the cadaver.
Plan to conduct this exercise at least ten different times before you advance to the next stage, which will be to train the alert that you want him to give to you before you give him his reward. Only after he is giving a good "alert" on this exercise do you want to progress to hidden cadaver and different search areas and more complicated scenarios. This is going to take awhile. Be patient. In the end, careful training and consistent training will produce results.