Usually MCD will occur without any warning and infections typically last from two to seven days. Most pet owners notice little difference in their feline companions during a sudden onset of MCD, as, oddly enough, strange behavior is a characteristic closely associated with cats. For this reason, biologists debate the existence of MCD, saying that cats are virtually always in a disillusional state, thinking that they are in some way superior to humans. Another theory suggests the cats are correct. __TOC__