The spread of the deadly canine influenza in Rockland and Westchester has prompted one boarding center in Chestnut Ridge to close down. Since the initial outbreak, many veterinarians in the area have treated a number of dogs for the same sickness. The source of the virus seems to have cross species lines and originated from equine influenza. Greyhounds in Florida were the first to be effected and the flu has since been spreading across the country. In over 30 years Ossining veterinarian Dr. Glenn Zeitz, who alone has treated 25 dogs for the illness, says he has not seen anything like this before.Symptoms of the flu include coughing, being lethargic and not interested in eating, having a high fever of more than 104 degrees along with having elevated blood counts. The treatment to fight off the invading organism requires fluids, oxygen, antibiotics and treatment for severe bronchitis.