The fungus that causes 'Valley Fever' is very common in the soil of the Southwest US (and probably northern Mexico). Most people who live in the SW US are infected by it within a few years of coming here. However, it doesn't do much to them--most people never know they had it. A small number of people will develop symptoms similar to tuberculosis. And a very small number of those people will die--usually people who also have immune disorders or other diseases. However, every part of the world has its own similar fungus. Along the Mississippi, for example, is a fungus that is spread to humans and animals by migrating birds, and it is similar in effect. Our vet, who has extensive ferret experience and has been practicing in northern New Mexico for some years, does not believe Valley Fever is common in ferrets. Given the dry climate, frequent wind, and presence of the fungus in the soil, you'd expect to see it here. But it isn't even seen much in people or animals who spend a lot of time out in the blowing dust (where the fungus spores are). In my opinion, healthy ferrets, just like healthy humans, dogs, etc., may be infected by the fungus, but should not suffer serious effects. Obviously, those with pre-existing illnesses would be more susceptible. In any case, unless ferrets spend a lot of time digging in the dirt or play on floors that are very dusty, they are at a lower risk for Valley Fever than a toddler playing in a sandbox. If a fungus does defeat a body's immune system, it can be very difficult to get rid of. Most treatments take a long time and some are hard on the body. I think (but don't know) that these fungal lung infections aren't transmitted from animal to animal directly, in general. I think the fungus has to spend some time as a spore in the dust or some other situation before it is able to grow in a new host. (Any mycologists out there are invited to correct these assumptions!) Jacqueline [Posted in FML issue 2719]