Aggression in the order Carnivora is something natural, natural large-sized, both small or size medium. Part of his system of survival, the use it gives it his way of positioning in the social structure of the herd, gain in the fight for food and spaces of hunting, as well as being the backbone of the path of socialization and hierarchy. This scientific, conclusive fact after many studies of the same nature, unconditionally supported the idea that there is some more aggressive than other breeds. ETOLCANIN studies have been performed on specimens of Canis Familiaris (dog), with agitated or pathological aggressive behavior that has come to the conclusion that in most of them the trigger you has been: 85% a bad or null socialization (fear, aversion, habituation, lack of social attitudes); 32% A tenure or not efficient guided by the owner (loose guides or too hard, not reading behaviors and signs), 17% problems Physicists (aggressiveness by pain), 9% other. In this study have been introduced all kinds of breeds, German Shepherd, Doberman, Pit Bull, American Estafford, dachshund, Beagle, Rottweiler, Pointer, Pincher, among many others. This study in addition to others made in the University of Cordoba, El Hospital Juan Canalejo of the A Coruna, Royal College of Veterinary Surgeons or the Department of biological sciences of the University of Lincoln are the same, the aggressive race does not exist and has never existed, what if he says is the existence of copies of all kinds of races that acquire an aggressive behavior in top grade due to a breeding and irresponsible possession, sometimes becoming pathological, by not knowing how to treat it or not wanting to do it. From ETOLCANIN we believe has not taken into account the opinion of the canine behavior specialists in drafting a law, which is mob and discredits a number of races just as prepared as the rest to live among us. The dog is only and exclusively what makes the owner of and if the dog fails at something, what the owner should ask is: in that I have failed I with my dog?. The copy is not guilty of belonging to his race, the owner if it is educate mistakenly.