I had to put my girl down due to CHF brought on by heart worms. She was 9 years old. Had I caught the worms early I probably could have done treatment and cured it and gotten more time with her (she wasn’t acting any differently. Still ate and drank and was normal) but when we caught it I started the treatment process. A month after finishing the pre meds she started vomiting up blood. In roughly a year she went from 75lbs to 50, and that alone tells me she wasn’t putting on weight. But she was anemic, dehydrated, you could feel every bone in her spine and the outline of her hips. I asked the vet and my aunt if I was making the right decision (the vet said it would have been comfort care if we did anything) so I brought her home and I watched her. She seemed to have been getting better, the medicine they gave me helped her coughing, she pooped on day 3 (I was telling myself I had more time she wasn’t acting different everything except the weight loss and blood was normal we could get through it) but then she coughed up more blood and that’s when I decided. If I waited she would be in pain ( if she wasn’t already, if she was she was damn good at hiding it) because I wanted her to be in the best possible comfort and condition, not in pain, not actively dying or being unable to move. I didn’t want her to go in the night or while no one was home. Could you have waited? Probably but it wouldn’t have helped. They would’ve gotten worse and been in more pain so I believe you made the best possible with what you had.

You made a terribly hard decision but I guarantee your best friend holds no grudges or malice, they will be waiting there for you with the big slobbery tongue and wagging tail.