Hello all

I have had 2 Degus for about 8-9 years now and one recently died about a month ago. My last one bob is starting to fit (Or what i think is one) He goes nuts in the cage for about 2 minutes until i hold him and once relaxed he comes around again. Is he on his way out ( Sorry for the words ) but i am worried about him? He his my favourite as he always comes to me unlike the other one did and i will miss him. How long do i have left, i know he is old and struggling but i need to know from others who have been through this when to expect the inevitable