It's some kind of sickness or something you can get in the desert, like the states of AZ, NV, etc. I'm not sure but heres what I found on it; "Valley Fever is a lung infection. A fungus becomes airborne when dust around construction areas and agricultural areas is transported by the wind. When spores are inhaled, Valley Fever can result." on here though it's saying most people get it in AZ, southwest AZ, great that's where I live and it sucks, it also says people who live in SW AZ has or will get Valley Fever at some point., "Yes, dogs can get it and might need long term medication. Horses, cattle sheep and other animals can also get Valley Fever. " I know it can be deadly, but only like 1% of the people die from it.