My dog had an enlarged heart and spleen and could no longer get around because she had bad back legs also. She was 13 and a Cairn Terrier. I protected her, carried her in and out because she couldn't manipulate steps and took the best care I could of her. She was on heart medication and several other medications. The decision was made after consulting the vet that she was not making any progress and her life was uncomfortable and euthanasia would probably be best for her. Long story short. Took her in and the sedation shot caused her to scream and come up off the table. She even tried to bit the assistant and she has never even attempted to bite in thirteen years. The shot was given in her back leg. I thought the sedation shot was to calm her down, not hurt her. Does the shot usually cause pain? Also, she lifted her head and I had to hold it down when the final shot was given. She did not cry out on that one, but I knew she felt it. Is this common? After hours of crying over the fact that I had to put her down this haunts me every day. Her last few minutes of life were painful. I am just trying to make sense of what happened. Thanks for your time.