I'm happy to be corrected on both counts.....
TDM, I always knew when you'd written my ASR - there was a total absence of joined-up writing, or even english.....
2 minutes after I posted that, I realised where the confusion lay...
'The Hamsters' were the first group of UK heart transplant patients; they were given steroids, which caused them to have 'hamster cheeks'.
My SWMBO tells me the Guinea Pigs wre recently on a documentary, but she can't remember the details....