hoof abscess
Fact: Hoof abscesses are one of the most common causes of sudden-onset severe lameness in horses.

Fact: Complications can delay hoof abscess healing.

Fact: In most cases, horses recover well.

And, until recently, there wasn’t much more scientific data on subsolar abscesses than that. So researchers from the University of Pennsylvania School of Veterinary Medicine (Penn Vet) set out to put more hard data behind these common hoof ailments. They wanted to identify trends that could help horse owners and their veterinarians better manage abscesses and more accurately anticipate how they’ll heal and if they’re likely to develop complications.

Stephen Cole, VMD, MS, Dipl. ACVM, a lecturer in the Penn Vet Department of Pathobiology, in Philadelphia, worked with colleagues to collect information about 160 hoof abscess cases in Southeastern Pennsylvania horses treated by the university’s large animal hospital field veterinarians.

After evaluating their data, the team determined that:

  • Subsolar abscesses occurred mostly in the front limbs;
  • They were slightly more common between June and November compared to the rest of the year;
  • Abscesses along the coronary band required longer veterinary treatment than those occurring elsewhere;
  • Treatment of abscesses that occurred during summer lasted 10 times longer than those diagnosed in winter (dry weather could affect healing, but more research is needed to better understand this phenomenon, Cole said);
  • Horses with abscesses in multiple locations within the same hoof were more likely to have secondary complications;
  • If the veterinarian found the abscess’ draining tract when he or she first saw the patient, healing time improved by 27%;
  • Male horses were more likely to get hoof abscesses than females;
  • Male horses took significantly longer to heal than did females (further research would be required to understand this, as well, Cole said); and
  • More severe lameness was associated with a shorter healing time (possibly because the severe lameness suggested the abscess was about to burst and resolve).

“While there were some surprises, in general, this research supports what ‘we know already,’ ” said Cole. “But it does not mean the information is not valuable. For example, if owners have a question about the likelihood of complications, this study may provide the clinician with a blueprint for some evidence-based answers.”

The fact that so little research exists on such a common clinical issue in horses is surprising, but also somewhat understandable, Cole added.

“It’s possibly because this disease does have a good clinical outcome in general, so there is a general feeling that the current standard of care is likely the correct approach,” he said. “I also think that since this problem is handled relatively easily by farriers and primary care clinicians, it rarely requires referral to a veterinary school hospital or referral center, which are the research hubs.”

Even so, gathering data about the disease—despite its prevalence—can help veterinarians care for their equine patients better and with more confidence. “We know medicine is at its best when it is supported by scientific evidence, and studies like this will help build that body of evidence,” Cole said.

The study, “Factors associated with prolonged treatment days, increased veterinary visits and complications in horses with subsolar abscesses,” was published in the Veterinary Record.