The Dutch version has "Vlaamse reus" (a kind of rabbits, and you may recognize the second word from Rebekah's last name - it's indeed a breed of very large and sometimes really enormous rabbits) and "Vlaamse gaai" (some bird), so it managed to preserve the ethnic link in the names while still having an animal in more or less the same category as the guinea pig, and a bird. Thus allowing the preservation of the comment of Neville's guinea pig still having feathers.