My cat is getting old =(

Mine was put to sleep aswell about 3 weeks ago. We could never tell there was something wrong with him... But he seemed to be in pain for quite a while... so they had to put him to sleep aswell. My cat bram was 13 years old.

And now my other cap bop (Also 13) keeps searching around the house for bram. And he's suddenly getting alot thinner himself and barely eats anymore...
Could it be that he misses his friend? I think its so sad...

But yeah goodluck ):
Condolences