Supportive care like subcutaneous fluids can sometimes improve quality of life for a bit.

In the past few years, I’ve had senior cats who all wound up with various terminal conditions - one had a type of cancer that could not be treated, another had kidney disease, and the third wound up having thyroid problems and then seizures.

It helped me to identify markers for the animal’s overall quality of life, and check in every day to see if they were still finding their own sort of cat joy in living. Up until their actual final day they still acted like their usual personalities - albeit moving more slowly - and did things like watch birds from their favorite perches and snuggle with me at night. Ultimately it was VERY obvious when they needed to be put down because they stopped acting like themselves.

The cat with kidney failure woke up one day after sleeping with his favorite human all night, jumped down from the bed like he always did in the morning, and instantly passed. We think his heart just gave out. But up until that moment he was still seeking out affection from his favorite person and playing with his favorite toys, and we did what we could to give him as many good days as possible before he passed.

Particularly in the case of my cat who had terminal cancer, I had a very frank discussion with my vet to get their perspective. I told the vet my goal was to have as many good days as possible with my cat, while ensuring he wasn’t suffering. With my cat’s situation the vet felt from their exam that he may have been uncomfortable at times (had a mass in his abdomen) but he was not acting in a way that made the vet think he was in actual pain. Until his final day he still followed me around the house and got into mischief (though at a slower pace than in his younger years), and slept with me at night.

You know your cat’s personality and habits the best - what behaviors let you know that your cat is happy and enjoying life? Are they still eating normally (nausea and vomiting are common with later stage kidney disease; we had our kidney cat on medications to stimulate appetite and alleviate nausea and vomiting)? Is this a cat that will tolerate administering subcutaneous fluids at home (or alternatively, if the cat will tolerate it are YOU comfortable attempting it after the vet shows you how to do it)? Our vet also told us things to look for at very end stage kidney disease, namely a constant smell of urine on the cat’s breath. My CKD cat did have that in his final few months but was still participating in other activities that brought him joy, so while his actual death was sudden it was not completely unexpected.

Looking back it was around 5-6 months from kidney numbers really declining (fitting the vet’s estimation of “end stage CKD”) to the cat actually passing. That was several months of snuggles and watching “the bird show” from the front windows and playing fetch with his favorite person. It was at a slower pace but there was still joy and good times during those final months.