It depends on the situation, on the breed of animal, and on the education, you have given to your little friend. But, there are some specific cases when the animal is afraid of going to the vet and feels uncomfortable, and in some cases uncontrollable as well, that is why it would be great to inform yourself about how to treat your pet, hence, you have to make a little research, (So did I) and here my advice would be to
visit this page of VETERINARY SCHOOLS which has different programs aimed to satisfy the general knowledge for specific breeds and some specific health issues, so, to be frank, that was very interesting, useful and well organized so that you as a reader, would understand everything) Thank you, guys!