Is A Synovial Infection The End Of A Horse’s Athletic Career? Not Necessarily

Infections of the synovial fluid in a horse’s joint can end an athletic career—if not their life. Drs. Danielle Crosby, Raphael Labens, Kristopher Hughes and Bryan Hilbert, with the School of Animal and Veterinary Sciences at Charles Sturt University in Australia, and Sharon Nielsen examined the records of 186 horses the hospital saw over a nine-year period.

Synovial infections present diagnostic challenges. Of the horses with synovial infections seen at the hospital, 65.6 percent of them were from penetrating wounds; 151 of them had one joint structure affected, three horses had three structures affected and the rest of four or more joints infected, mainly caused by infections carried by the blood to other joints.

The majority of the horses with joint infections were treated with synovial lavage (93.8 percent). Of the 186 horses that received treatment, 145 of them (90.1 percent) survived to discharge. The researchers were able to follow up on 121 of the horses and 79 of them (65 percent) were able to go back to work, though most did not return to the level at which they were used before the infection. Foals were less likely to return to intended athletic use (53.3 percent) than adult horses (68.9 percent).

The scientists determined that increasing the days of antimicrobial treatment increased the chance of survival; however, the horses treated with doxycycline were 2.5 times less likely to return to full athletic function. This is most likely because of drug resistance and doxy’s use in younger horses.

Nearly half of the study horses were used or intended to be used for racing (45.4 percent); of the 58 racehorses treated, 31 (53.5 percent) started at least once. Interestingly, Standardbreds performed better than Thoroughbreds after synovial infections. Researchers speculate that this is because Standardbreds are a more-robust breed and because they tend to race longer than Thoroughbreds, having more starts.

Read the study here.