Possession guarding in dogs is a serious issue. This is even more serious when the dog that practices it is exposed to strangers on a regular basis or to children. In both of these cases the dog exhibiting the behavior is most likely approached by people who do not know of this issue or how to behave around a dog with this issue.
Solving this problem takes time. You are not going to be able to make your dog give you any object you want whenever you want it in a single day or even two. Depending on the degree of the possessiveness it may take weeks or months to fix this problem. Don't give up. It can still be done. Before you reach the point when you can take anything from your dog you want it is a good idea to remove toys and other objects your dog guards from its access. Put toys away so that you have to give them to your dog for your dog to play with them. Then when you do decide to give your dog a toy keep treats at your disposal to toss to your dog in order to make him give up the toy, even if it is only long enough to pick up the treat and swallow it. This is the way it has to start. This begins the connection for you dog between you and all good things. The idea is that from this point you will be able to progress ever so slowly to the point when your dog will take the treat out of your hand and then to the point when you can trade a treat for the toy and then to the point when you will be able to tell your dog to drop the toy and he will allow you to take it.
Again, this is not something that is fixed over night, it takes time and patience. Other important factors can include other areas of your life with your dog and how your dog perceives your interactions with each other. In some instances this can be the result of allowing your dog, or making your dog take the position of leader. If this is the case you will need to establish yourself first as your dog's leader and then proceed to work on other issues after that. If your dog does not look at you in a leadership position he will not respect your wishes or your commands. If you have not already established yourself as your dog's leader a structured walk is the best way to do this in my opinion which Cesar Millan supports. This includes boundaries like where your dog must walk in relation to you, and making your dog become calm before you take him out and making him follow you out the door and possibly for the entire walk (I like to keep dogs with their heads parallel to my thigh with everything from their shoulders back behind me).
Considerations for a City Dog. And Dental Supplies.
2 months ago