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 Blood-Horse of March 7, page 1423). 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). Two other stallions, Spotted Man and Black Jack, and the females Foxy, Blackie, and Ten-Two, have been reported culture positive.

The California jack Rooster Sunrise, which tested positive for a CEM-like organism in an unrelated incident, has been test bred. 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.

The United States Department of Agriculture noted that isolation of the CEM-like organism has not been associated with clinical disease, thus, “Its impact on domestic equine production and international movement of horses cannot be accurately stated.” It also concluded that the prevalence of this CEM-like organism has not been studied in donkeys and additional infections might be found