A dog that snaps is a dog that is communicating to you that he is your leader and he simply wishes that you leave him alone while he eats (leader eats first...it's canine instinct). This is why it is so important to be 100% pack leader at all times, consistently. When someone is not or is wishy-washy about it, the dog becomes either unsure and tests you, or simply is convinced and becomes alpha. A dog communicates by growling, then snapping and biting. It happens because of the humans. It is the responsibility of the humans to understand this and be alpha 100% of the time or you will be tested by your dog.
Dogs who are not 100% secure with their place are stressed dogs. Since we cannot allow a dog to be pack leader 100% of the time allowing the dog to make all the decisions, the dog becomes stressed and anxiety ridden. Sure, your dog may look happy because he is always excited, however excitement in a canine animal is NOT happy. It is just that, excited. Most dogs in America are not stable, balanced dogs because most people do not understand this.
Dogs also have an instinct to migrate and how many people do you know who own dogs? Now how many dogs do you see going for walks? How many dogs that you DO see walking are walking in front of the humans? Pack leader goes first. Whatever happened to a dog heeling?? So dogs are pack leaders during their walks (in front), with what little walks they get in the first place, and then they get home and their owners expect them to behave. To not guard their food. They expect them to listen to them, expect them to not bolt out the door, not bark obsessively, and to not chew things up, all the while wondering why they are so hyper, etc... They are wishy-washy about who is leader.
A dog that does not get a daily walk develops mental stress because he has this instinct to migrate. Packs of dogs get up in the morning and walk, they hunt to find food. Nope, sorry a big yard and/or big house does not cut it. It's just like a big cage to them. Most dogs are unstable, hence the reason we have so many dogs getting killed in pounds. It's the humans’ fault and oh so very sad. We take these animals and we have them live with us, yet we only take what we need as humans and do not give the dog what HE needs as a canine animal. Then we kill the dog for being unstable and get a new puppy. Nice cycle huh? We blame the pet overpopulation problem on breeders, however have you ever heard of supply and demand? If everyone were to keep their dog for life the demand for new pups would go down. Breeder does not sell pups, breeder does not breed as many...