I had my girl for 15 years, hits hard. She had a stomach tumor burst and was bleeding internally. So we rushed her to the Emergency Vet.
She was barely alive when we got there. I sat with her in the back our van. Only thing that calmed her down was me otherwise she kept trying to get up. I made her comfortable as I could.
Once they administered the euthanasia drugs. I remember her scooting up to me more and putting her head in my lap. She closed her eyes took a few struggling breaths and finally a sigh of relief and than no more. Was just like she went to sleep comfortably. Didn't believe she died even though I knew she did. I cried for a long time petting her head until she started to get cold.
I'm very fortunate I could be there for her. I've had a few dogs growing up that passed, but none that hit me that hard.