This gurgling, curdle-furred Muppet was diagnosed with stage III kidney disease at 7, at which point it seemed likely he would live only another couple of years. I knew his breed was prone to it, and that he was not ethically bred, when I adopted him, and did so assuming that he would develop CKD from the jump. He did. And that is how it felt. Of course. So every year after that was stolen time, and he lived to an improbable 14+ years. The entire time, I held him lightly, knowing I was going to have to let him go. It made those years really good. I really cherished them. I am grateful for them and for what they taught me.
Losing him was expected, and an easy transition. Losing his two brothers unexpectedly within the same week was horrific. I am still broken even two years later. My boyfriend is still broken. Their baby sister is still broken. The anticipatory grief towards her, my bright little star, our Fancy, is bone-crushing at times, because those final moments are crowded so near, still. I am struggling mightily with it. I cry often. I am Very Afraid.
All I can say I've learned, after having our lives torn apart:
Make their lives, every day, good lives. Keep them in fresh food and water, keep them clean. Every day make sure their eyes are bright for at least an hour, all told. If they cry, learn to understand, and tend them. Check on their paws, ears, and mouths regularly. Try to teach them tricks. Show them new things often. If they interfere with something of yours, let them have it or give them something like it of their own. Leave a place beside you, always. If they misbehave, do not punish the behavior -- address the underlying need, it is valid. Play. Love. Gentle hands. Soft voices. Do not turn away during the times you are tired or frustrated or do not know how to fix something. Do something. Know that they are living things with interiority and feelings, and they have an image and an idea of you that encompasses how you sound and smell how you touch them, that they have an understanding of what you are like as a person, and they have no choice but to be with you, so make that person a good one. If you feel that you aren't very good and don't know what you are doing, keep trying. Ask for help if you need to.
A being guided by love even when he had literally no idea what was going on.
The best balm for borrowed grief is to simply do your very best, every day.
It'll break you sometimes anyway. But to that, also, I say: of course.