CHICAGO, June 14 (UPI) -- Canine influenza has cropped up in Illinois, prompting experts to warn pet owners to be on the lookout for the illness in their dogs.

The "dog flu" has been found in 20 states after its initial discovery four years ago in racing greyhounds in Florida, the Chicago Tribune reported Saturday.

"The fortunate part is that most dogs recover just fine from this influenza, just like most people do," said Dr. Cynda Crawford of the College of Veterinary Medicine at the University of Florida.

Symptoms include a cough, fatigue and throwing up phlegm, experts say.

The dog flu was confirmed in Illinois after Animal Ark Veterinary Clinic experts recorded an increase in cases, about 50 or 60, involving dogs with symptoms of the illness, clinic owner Dr. Derrick Landini said.