Steven Seabaugh, the track's veterinarian, said 182 horses were deemed to be in need of testing when the first cases of equine herpesvirus were found Oct. 14 and 48 positives were found, including the three fatalities, the Chicago Tribune reported Friday.
Seabaugh said the remaining 45 horses have recovered or are recovering.
"The overwhelming majority of our 1,900 horses are healthy," Hawthorne President Tim Carey said. "What hurts most is all the rumors. Things are progressing and we're going to get through this."