After treatment, the horses with navicular disease get 30 days stall rest, and then they are shod appropriately. Snow usually
observes them at 30 days post procedure to see the response, then they can do light work. He examines them another 30 days
later to further judge the response and to determine whether it's OK to increase the workload.
Snow gives the horses one ESWT treatment; it either works the first time or not at all, he says.
On the suspensories, the layoff time is usually the same, about 30-45 days, then they can resume light work. He likes to use
the aquatic treadmill if possible. Most of his cases are in a farm setting, so people are fine with the extended (30-day)
rest period. With the racehorses, he suggests to hand walk them in addition to the stall rest.
According to some research, ESWT is an effective method of decreasing clinical signs of lameness associated with osteoarthritis.
In a study comparing horses treated with a common non-steroidal anti-inflammatory drug, ESWT performed better, promoting improvement
in clinical lameness and increased synovial fluid total protein, and increased amount of glycosaminoglycan released into the
bloodstream. ESWT treatment reduced the clinical signs of pain measured by lameness evaluation 42 days after the final treatment.
The results of the study suggested that ESWT is an effective method of reducing clinical lameness and synovitis, but it does
not improve gross or histologic progression of arthritis significantly; thus, it would be best considered in combination with
a chondroprotective agent.
Effects and concerns
Among possible concerns of ESWT for horses is potential local analgesia after treatment, and for bone micro-lesions, micro-fractures.
McClure and colleagues studied these possible effects and found slight cutaneous analgesia for three to five days, but no
bone lesions were present. Data indicated that a horse should not be subjected to strenuous activities where local analgesia
pre-disposes the horse to injury for at least four days after ESWT.
"I think the analgesic effect is definitely there," Rodgerson says. "I think we are getting some initial tissue damage from
the shock wave and therefore the inflammation assists in the healing phase, similar to cryotherapy or pin firing for bucked
shins or shin splints, which somewhat traumatizes the area which stimulates inflammation which helps in the healing phase."
Snow says effects sometimes can be observed rather quickly.
"I'm fairly sure that there is some analgesia associated with the treatment because with the navicular disease, for example,
pre-treatment they are pretty lame, and the day following the treatment, they feel pretty good and seem much better," he says.
"It's just an empirical feeling, but I think it certainly seems to occur post treatment."