No, you are just doing the right thing like the rest of us.I think guinea pigs are so cute but they poop so much oh my garsh. Since I like to keep my little Russian as clean as I can for his health, I just don't put him with other animals. And truely I wouldn't want my little guinea to be exposed to a tortoise either. I've exposed Sapphire to other animals in the past but I just don't make it a daily practice even for a short time anymore. Maybe I'm an over protective mommy dearest