Hi guienapiglet. Only just saw this. Gethin was a boar, but a very small one. He was the "cover boy" in the July issue of Guinea Pig Magazine. He was such a charming and gentle rodent.
Rosie sounds wonderful and 5 1/2 is such a good age. Sadly Gethin was not quite 4 when he went to the Rainbow Bridge. He'd had a problem with recurrent colds, which I thought was down to his short nose, but then had one he couldn't shake. The vet and I both had suspicions and an xray confirmed an enlarged heart. Despite aggressive treatment, he only lived another couple weeks, but was gentle and loving right to the end. I think piggies DO sense your upset and can be amazingingly comforting, like your Rosie. RIP Rosie. RIP Gethin.