Hi, Ella,
Sorry to hear your boy is unwell. My boy, Bindi, will be 10 come Spring and needs regular (every 5 monthts) molar trims under anesthesia. It is always very stressful for me, because I know there is always a slight risk with bunnies that may increase with age. However, I know he needs them done and that it’s the only option to keep him healthy.
Like Toby mentioned, getting pre-anaesthetic bloodwork is always a good idea, but especially so in a senior. I usually do the bloodwork for Bindi every second trim just to make sure all is well and he’s healthy enough to undergo the procedure.
Luckily, my boy does quite well and always bounces back pretty quickly.
Of course, the decision is yours alone but were I in your situation, I would do the blood work and then see what the results are. If he is healthy enough to undergo the procedure, then I would go ahead and do it because it’s the best option for him to regain good health.