If your dog is gravely ill, very old or injured you may have to make the difficult decision about whether or not to put him to sleep (euthanize) . The important thing to remember, is that if your dog is suffering and you and your vet feel he will not regain a good quality of life, then euthanasia is a humane and responsible choice.
Translated from ancient Greek as "Good Death", euthanasia is usually performed by injecting a large dosage of barbiturates (an effective anesthetic) into the blood stream. This causes rapid sleep, unconsciousness and then cardiac arrest, usually within less then a minute. Some veterinarians may be able to come to your home, but mostly euthanasia takes place at the vet's clinic.
Some owners choose to be present while their dog is put to sleep. This gives them a chance to say a final goodbye. It is also the chance to reassure and comfort your dog and make sure that the final moments are filled with warmth and love.
However some owners find that it is too painful to be present when their dog is 'put to sleep'. This is an entirely acceptable choice as well. The vet will encourage you to spend some time alone with your dog before they give the injection. They will be kind, compassionate and make sure that the final moments are peaceful.
Your dog will have become a beloved family member and so it is entirely normal to feel a very deep sense of grief when he dies. Remember all of ,the wonderful and positive times you had together and be assured that you did your best to love your dog, care for him and make him happy right to the very end.