A product that could stimulate the immune systems of newborn foals to better fight infection of Rhodococcus equi would be very beneficial, said Steeve Giguère, DVM, PhD, of the University of Florida, at the 2008 American Association of Equine Practitioners convention, held Dec. 6-10 in San Diego, Calif.

Pneumonia caused by R. equi is endemic on many farms, he said. Studies have shown that immunostimulants decrease the incidence of respiratory disease, but there is no data looking specifically at R. equi-caused respiratory disease.

The researchers, Giguère said, hypothesized that immunostimulants can enhance immune system cells’ ability to kill R. equi.

Seventeen foals were involved in the study, and they received Zylexis (a commercial immunomodulator offered specifically as an aid for reducing upper respiratory disease caused by equine herpesvirus-1, or EHV-1, and EHV-4), EqStim (a commercial immunostimulant), or saline. Blood and bronchial lavage (BAL) cells were collected on Days 7 (pre-treatment), 19, 31, and 43. The cells of the foals were infected in vitro with R. equi