Septic Arthritis, which is basically what Shuttle has, is a bacterial infection of the joint.
I’ve found a few sources, one of which says:
A very important part of treatment is joint drainage and lavage. “This therapy is critical in the early management of septic arthritis. It dilutes the byproducts of inflammation, cellular debris, and bacteria, all of which are harmful to the cartilage within the joint,” explains Dr. Richter.
In addition to drug therapy and joint lavage, stall rest, bandaging, and physical therapy also aid healing. “Passive range of motion exercises can reduce the degree of joint stiffness,” says Dr. Richter, “but allowing vigorous exercise too soon in the rehabilitation period can make the joint prone to developing degenerative joint disease.”
With early and aggressive treatment, more than 85 percent of adult horses can survive with septic joint disease, and more than half of racehorses have been reported to return to competition. Foals with septicemia and more than one joint affected have a poorer prognosis for future athletic soundness, but, like adults, have a much better chance if started
on treatment early.
I do hope, that she’s not in the 10-15% of adult horses that have to be put down because the infection spreads.
Please pray for her!