A mystery dog disease which began to sweep the US last summer is still being investigated. Vet labs in many states are looking into a new, unusual disease that's been threatening the pet population and worrying animal health professionals, who are working tirelessly to determine the cause of the mysterious disease and work on cures. Described as a respiratory disease and pneumonia that doesn't respond to antibiotics, the symptoms of the new disease include coughing, sneezing, discharge from the eyes or nose and general fatigue. The illness is progressing quickly in some dogs, researchers say, with a few falling severely...