My first cat lived 25 years and when she started to fail from Leukemia her back legs gave out and the vet said I should put her down. Watching her drag herself around the room by her front paws made me a wreck. I concocted a platform and some wheels from a toy to help her but it was quite a sad sight watching her fail. She lasted a few weeks like that and I knew I had to put her down, best I could do was go in with her for euthanasia.
Another cat had a tumor on her head and she stopped eating. I had an idea and went on you tube and found a veterinarian who had a video showing how to put the cat food in a blender and used a turkey baster syringe to squirt the food into her mouth. I did this 3 times a day for 3 years to keep that cat alive. One day she collapsed and I knew it was time.
Another cat had a thyroid condition and I got him treated and he lasted a few more months. He started hiding in the closet and then one day he let out a shriek and started convulsing, the scariest sight and sound that I can still feel in my bones to this day. The vet told me I waited too long (obviously) and that's what happens when animals are about to die.
My current cat was diagnosed with IMHA ( auto-immune disease that kills red blood cells ) but with medication he has been doing well. I came close to putting him down but the vet kept him alive with numerous transfusions until we found the right medication. I would like to share some wisdom. When an animal starts hiding, changes it's behavior and becomes less playful, or stops eating, take it to the vet immediately. Watch the gums, if they lose their pink color and turn pale it's serious. There is a fine line between waiting too soon or too long to put them down. Animals hide pain VERY well, unlike humans. Make sure you're not keeping the animal alive for selfish reasons. And do your homework when buying from unscrupulous pet mills.
Best of luck to all of you animal lovers and thanks for sharing these personal stories. It made me feel like I'm not unique about how I feel so strongly for animals.
Hobo - The NY Pinball Mascot and supervisor/helper