I'm naughty, I'm not good with supplements, etc. But there was this one year, that my babies kept catching .... what appeared to be colds, but I know had to be flu. It was just a very unhealthy time and puzzling. I heard that some shelters were using Nupro in their feed and loved the results. So we got a jar. Coincidently, or not, there was an immediate effect. Our ferrets also never got one flu/cold while on that supplement the next two years. We stopped using it as it was an added expense for us adn one that we opted to cut. We do get the occasional ferret flu now. Wolfy [Posted in FML issue 4378]