We visited him again today and while the results are still not in the vet said he is so sick it would be best to put him down now rather than wait a whole weekend before any results come back. We played together for about 30 minutes until he went to sleep and then had the vet put him down. I then buried him in the garden with a lavender shrub on top.
I talked to the vet about showing his brother and they said yes as he will then know what happened. He spent about 10 minutes sniffing him all over and looking at us but seems a lot calmer tonight, I guess it was good for him to know rather than walking around the house looking and calling out for him like he has the last few nights.
It still seem so close to the other cat passing and so young for this poor little guy.
