Cribbing isn't just annoying for owners and destructive to property. It can also negatively impact your horse's health and is notoriously difficult to control. But there's a glimmer of hope for owners with cribbers: Researchers found that a surgical procedure intended to control cribbing is very effective.
Daniel J. Burba, DVM, Dipl. ACVS, professor of veterinary surgery at the Louisiana State University School of Veterinary Medicine, shared the study results with attendees at the 2013 American Association of Equine Practitioners' Convention, held Dec. 7-11 in Nashville, Tenn.
Burba said that about 4-5% of the horse population cribs. While the etiology, or cause, of the vice remains unclear, researchers know it can have several negative effects on horses' health, including:
- Poor performance;
- Weight loss;
- Excessive incisor wear;
- Flatulent colic; and
- Epiploic foramen entrapment (in which a section of small intestine threads itself through the epiploic foramen—a narrow opening connecting the two sacs of the abdominal cavity—and becomes trapped).
While there are various surgical and nonsurgical treatment options, their success rates for effectively controlling cribbing vary, Burba said.
A horse in the act of cribbing. The arrows point to the section of muscle removed to alleviate cribbing.
Photo Courtesy Dr. Daniel Burba
"It is unsure exactly how surgery alleviates the act of cribbing," Burba said. "I believe it alleviates the ability of the horse to retract its throat (larynx) during the act, thus the horse does not get satisfaction. The reason I believe this is the reason is because the horse can still place his upper incisors on a horizontal surface after surgery but when they try to crib they are unable to adequately retract the larynx, thus become ‘discouraged’ and no longer try."
The first surgical treatment protocol was described all the way back in 1926, Burba said. Named the Forssell's procedure, this method involved transecting the horse's "strap muscles"—the paired muscles under the throat (sternothyroideus, sternohyoideus, omohyoideus, and sternomandibularis). Unfortunately, he said, the procedure was not cosmetically acceptable to owners at the time.
Veterinarians later modified the procedure by transecting or cutting a piece of nerve, rather than the sternomandibularis muscle itself; however, success rates were variable, Burba said.
Then, Burba and colleagues modified the procedure again and began using a laser to transect the appropriate nerves and muscles, called the laser-assisted revised modified Forssell's procedure (or LARMF).
To determine the most recent procedure's success rates, Burba and colleagues performed a retrospective study on 119 cases from 1994 to 2012. The team reviewed the horses' signalment (i.e., age , breed, sex, and other descriptors), how long they'd been cribbing prior to surgery, postoperative complications, and the outcome (the team considered cases successful if the horses stopped cribbing for a year or longer after surgery).
A horse one year post LARMF sugery to alleviate cribbing, with cosmetic results Burba describes as excellent.
Photo Courtesy Dr. Daniel Burba
Key findings from the study included:
- Forty-six mares and 73 male horses underwent surgery during the study period;
- Quarter Horses, Thoroughbreds, and Warmbloods were the most common breeds presented for surgery, and most of the horses presented participated in cutting;
- The team was able to collect follow-up information on 90 of the 119 cases. Of those 90, 76 horses (84.4%) stopped cribbing for at least one year following the procedure;
- Of the 14 horses that resumed cribbing within one year, all the owners reported the horses' cribbing frequency had decreased;
- The procedure had lower success rates when horses had been cribbing for more than three years prior to surgery;
- Twenty horses developed complications, including incisional infection, prolonged incisional drainage, hematoma (a blood pocket), seroma (a tumorlike collection of serum), and dehiscence (the reopening of a wound that has been sutured). Burba also noted that the latter three complications were mostly reported in early cases and aren't seen as much in present day cases;
- Horses that developed postoperative complications were more likely to have an unsuccessful outcome; and
- The owners of five horses—two racehorses, two cutters, and one dressage horse—reported decreased performance after surgery.
Overall, Burba said the LARMF procedure's 84.4% success rate was better than those previously reported for other treatment options.
"The LARMF is a very effective surgical treatment of cribbing in horses," he concluded; however, he reiterated that the procedure is less successful when the horse had been cribbing for three or more years or developed complications after surgery.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.
