I am glad your Osk is still doing well! It sounds like he is still enjoying life and has some energy so that is a very good sign.
Yes, it is sad to think of them having cancer and possibly having their life shortened because of it but we just try to enjoy every moment with them. I wish they could live longer but I suppose it is not the quantity but the quality of life that matters.
The one supplement I always seem to go back to is lactoferrin. It seems to really help when Timber sounds stuffy. I take a break from it after I have finished a bottle of 60 caps because it is expensive but I think it really helps the mucous membranes. It is found in the lining of our digestive system and helps to fight infection. I think it works just as well as the doxycycline antibiotic.