Most people would consider a cast on a horse to indicate a significant health issue. And they’d be right; problems requiring a cast are significant, and the challenges don’t stop there, with cast application; researchers on a recent study found that nearly half (49.5%) of horses with limb casts experience complications (such as pressure sores or cast breakage).

John Janicek, DVM, MS, Dipl. ACVS, of Weems and Stephens Equine Hospital, in Aubrey, Texas, presented a recent review of complications in 398 horses wearing half- or full-limb casts at four referral centers—the University of Missouri, Iowa State University, the University of Georgia, and Purdue University—at the 2011 American Association of Equine Practitioners convention, held Nov. 18-22 in San Antonio. 

Researchers made the following observations:

• Hind limbs were more frequently casted than front limbs;
• Soft tissue problems (severe wounds/severe tendon problems) were casted slightly more often than hard tissue problems (such as fractures);
• Complications included cast sores (45% of all casted horses), cast breakage (5%), secondary fracture (0.7%), and other issues. Complications generally showed up within two weeks of application regardless of the cast type used, with cast breakages usually occurring within five days;
• Bandage casts were much less common than traditional fiberglass tape casts (13.3% vs. 86.6%), but they exhibited a notably lower complication rate (34% vs. 52%);
• Limbs casted in a flexed position (such as to reduce tension on ligament/tendon injuries on the back of the leg) had complications in 71% of cases, compared to 48% and 47% of limbs casted in neutral or extended positions, respectively; and
• Institution also had a significant effect on complication rate, meaning some referral centers recorded more cast complications than others. ("It is most likely because of the variation in case presentations and number of cases included from the different institutions," Janicek noted. "This finding has no bearing on the individual institutions abilities to treat extreme orthopedic injuries.")

"Subjectively, we have always known which cases would most likely develop a cast complication (horses with loss of tendon or ligament support), but never had a firm grasp on the overall number (or percentage) of horses that encounter this problem," he explained. "Now we have objective information in regards to limb casting we can pass along to our client