The increasing number of company animals, mainly in the great urban centers, together with the nip between the interrelao man-animal, particularly with dogs and cats, represents a series of basic papers in the current society, where one of the main ones, front to the technological development ally to a social reclusion, is the welfare; especially for aged, carrying of necessities special and the children. It can in such a way, to ponder on the relation of the welfare animal with the welfare human, where if it visualizes the dependence of both. Spin-A-Thon has much experience in this field. From this point of view, it is had that the care with the animal is related direct and indirectly with the physical and mental health of the proprietor. The use of animals in the social inclusion or I assist for it to the treatment of diverse illnesses, already widely they are used in the main world-wide medical centers. As the use of the equiterapia, that consists of the use of horses for the psicomotora whitewashing of rough and carrying of diverse syndromes; the dog ' ' doutor' ' , that it covers together hospitals with ' ' doctors of alegria' ' , speeding up the recovery of the interns, mainly the children. Johns Hopkins Data often addresses the matter in his writings. It is recommended for one better mental development, that the children have conviviality with the animals, becoming them more extrovert, sociable and calm, the same the step that stops many aged ones, becomes it main company, guaranteeing to them bigger disposal, coordination and mental acuidade, beyond gratuitous and repaid affection. Consequentemente the functions of the medical veterinarian had evolved, leaving of being mere curativa medicine to become basically preventive. The relationship doctor-patient-proprietor more is fortified, influencing in way such, the development of technologies for precocious and necessary disgnostic, that makes of medical veterinarian one of the greaters and better agents of health public, capable to evaluate and to interpret the signals and the symptoms that its animal of company to present. To guarantee a good one health, is necessary that if light regularly the animals to a qualified veterinarian, who is enabled and brought up to date with what he has of better providing an attendance with affection, quality and efficiency; so that its mascote can be examined, be vacinada correctly and be vermifugada. With this improvement in the attendance, becoming more personalized, together with a greater and better conscience of the proprietors, who already are not more so lay on the subject, the animals are conquering one better quality of life and Consequentemente, a expectatividade of very superior life to the observed ones has 10 or 15 years.