The nurse mare (Miss VQ) which was leased to a Thoroughbred farm in Kentucky and found culture positive for the CEM-like organism has implicated two non-registered stallions (Hammer and Coal Digger) as the potential source of her infection.

The mare and two stallions are in quarantine and are being examined and treated in accordance to state law. Other known positive animals in Kentucky are the initial jack (Grey Jack) and the three nurse mares to which he was bred (Melissa, Duchess, and Simply Splendid). Melissa and Duchess now are culture negative and are undergoing treatments to qualify for release from quarantine. Two other stallions, Spotted Man and Black Jack, and the females Foxy, Blackie, and Ten-Two, have been reported culture positive. All are being tested and treated in accordance with state law.

The California jack Rooster Sunrise, which tested positive for a CEM-like organism in an unrelated incident, has been test bred to two mares. Those mares have tested negative on culture and compliment fixation tests.

Rooster Sunrise has been treated and will be re-cultured. This strain of CEM-like bacterium has not previously been isolated and is different from the Taylorella equigenitalis organism that caused the outbreak in Thoroughbreds in Kentucky in 1978. It is possible that the two CEM-like organisms in Kentucky and California will be designated as sub-species of the bacterium