My heart goes out to everyone here that has recently lost their pets
I lost one of my rats a couple of weeks ago, She was a fighter, but pneumonia got her. I felt bad because I'd left her with the vet in the morning, while he tried to save her, but when it became obvious nothing could be done, I gave permission to have her euthanased. So I wasn't there with her at the end, and I felt guilty. But the vet was fantastic! He wrapped her in a towel and carefully laid her back in the carry cage I have, so she wouldn't be too distressing for me when I collected her that evening. They treat her body with respect, and I'm grateful for that!
Over the years I've lost 4 rats, numerous rabbits, and 5 dogs. The rats have always died of pneumonia (they're prone to it), and most of the dogs lived a full life and had to be put down due to complications with old age. Only one had a short lifespan - she had leukemia and died naturally one weekend. We knew she was dying, but she was happy and not in pain, so we didn't go the euthanasia route. Then, one day, she just curled up my Mum's feet, put her head on Mum's foot, sighed, and died...
It's never easy losing them

And even harder when it's our decision to end their life. It always leaves me devastated! All the pets are buried in my parents garden - we joke that we'll run out of space soon
Euthanasia is painless, by the way. The animals are given an overdose of pentabarbital, which is an anaesthetic. So they literally go to sleep before they die, and they feel nothing.