striking dogs. >> more than 1,000 dogs sick in the chicago area alone. it's showing up in several states. alex perez more for us from chicago. >> reporter: this boxer mix named buster being treated with an oxygen mask and isolation after an outbreak that has chicago area doggie hospitals working around the clock. canine influenza. some 1,300 pooches in four midwest states most in the chicago area. at least six have died. elizabeth estes dog ollie got sick overnight. >> his cough was horrible. >> reporter: sick dogs become lethargic, run a fever and have raspy breathing. researchers tracing the virus to a rare strain of bird flu from asia. >> it's very easy to transmit. nose to nose contact, sneezing, coughing. if a dog stays on you, he's on