To not get dogs blood test done

[Desperatetime]

Elderly dog in need of pain relief for arthritis vet recommended a urinalysis to get an idea of how his kidneys are working and although the result suggested they are not working as well as they should be she is saying a blood test is better to get a better idea at a cost of £166 however pain relief hasn't worked as well as last time. Would I be unreasonable with a 17 year old dog to refuse the blood test and insist on pain relief in his last days as surely its important to just try and keep him comfortable.

YANBU. The stress of extra treatments and tests isn’t worth it to your lovely doggy

She wants to check his kidneys as the pain killers can affect them even more but he is 17 and I feel he might have other issues as well.

It’s not worth it for him then. I’d insist on painkillers for him. I know this might sound upsetting but 17 is an amazing age for a dog, make sure not to prolong his suffering if he is unlikely to recover too x

Can you discuss with another vet? I find some more pragmatic than others. I’d ask what would the blood test change? I’d also ask how well do the kidneys of most 17 year old dogs function?! We know kidney function declines with age in humans.