Odnos čovjeka i psa se, od svojih početaka, neprestano mijenjao i razvijao. Pas je započeo svoje putovanje uz čovjeka kao oruđe, pomoćnik pri lovu i zaštitar ljudskih nastambi, no vrlo brzo se pokazalo kako pas može pružiti mnogo više. Tako se danas pas nalazi u raznim, važnim ulogama u ljudskom životu, a ona medicinska, koju je relativno nedavno dobio, možda je i najvažnija. Psi se u medicinske svrhe koriste kao vodiči slijepih osoba, kao rehabilitacijski pomoćnici osobama u invalidskim kolicima, osobama koje se teško kreću iz bilo kojeg razloga, ali i kao pomoć osobama koje pate od dijabetesa ili epilepsije. Osim toga, oni mogu biti i terapijski pomoćnici koji pomažu djeci s posebnim potrebama, osobama s PTSP-om ili osobama s psihičkim problemima. Psi su čak i korišteni u istraživanjima koja su pokazala kako mogu otkrivati tumore i rak, u nekim slučajevima, čak i ranije nego moderna tehnologija. Većina istraživanja provedenih na ovu temu, pokazala da psi doista imaju značajan utjecaj na zdravlje ljudi.
The relationship between a man and a dog has constantly been changing and evolving. Dog began his journey, at man's side, used as a tool, a hunting assistant and a protector of human settlements but, as time passed by, the dog became so much more. Today dog has a lot of important roles in human life, and the medical role, which he was, relatively recently given, might be the most important one. The role of the dog used in medicine can be the one of a guide for blind people, or the one of a rehabilitation aid for people in wheelchair, or people who have trouble walking and moving around, but they can also be used as helpers for people suffering from diabetes or epilepsy. Other than that, dogs can be used as therapy aid for special needs children, people suffering from PTSD or sorts of mental issues. Dogs are even used in research which proved they can detect tumors and cancer, sometimes even in earlier stages than modern technology can. Most of research addressing this topic, of dogs used in medicine, show that dogs do have a huge impact on human health.