Hoof Measurements for Laminitis

Researchers at the University of Pennsylvania New Bolton Center conducted a retrospective case-control study to compare measurements of the thickness of the laminae (perpendicular distance from the inside of the hoof wall to the dorsal surface of the coffin bone) between healthy control horses and those diagnosed with acute and subacute laminitis.

X-rays of 18 laminitic and 32 healthy horses were obtained from hospital records and measured using digital images. Horses with chronic changes such as obvious rotation of the coffin bone (≥3 degrees), remodeling or sinking (distal displacement of P3) were excluded from the study.

The average lamellar thickness measurements in the proximal, middle and distal regions of the dorsal hoof wall were greater in the laminitic horses compared with the controls. The sensitivity and specificity of the technique was high, particularly when the measurements were considered as a ratio with the length of P3. The ratios being less affected by magnification and obliquity compared with the raw measurements.

Although they could not examine the positive and negative predictive values of the technique for the diagnosis of laminitis in this type of study, the authors concluded that these measurements of lamellar thickness are potentially useful for the diagnosis of acute and subacute laminitis with the advantage that no special radiographic techniques or markers are necessary.

–  Skelton G et al. EVJ 2024:14436

Loose Housing May Be Healthier

Swedish researchers reported on two studies comparing the health outcomes of horses housed in active open-air barns holding 24 horses with those of horses individually housed in box stalls with paddock turnout paired with another horse.

The open-air barns were complex setups with computer-controlled feeding stations, individual lying areas and a paddock area for free exercise. About 70 dressage and show jumping horses with an average age of about 8 years participated in the study over 4 years. The incidence of lameness, wounds (characterized as related to interaction with another horse or from an unknown cause), colic and days lost from training were recorded.

In one year of the study, there were 87 health events among the 66 horses. Horses housed in the open-air barns were more likely to have reported health problems with injuries from other horses and injuries from unknown causes most common. However, lameness and colic were more common among the horses housed in box stalls.

Notably, although there were more health events reported, horses housed in the open-air barns did not lose more days of training to serious problems. Minimizing turnover and reassortment, as well as allowing horses to acclimate to group housing seemed to minimize conflicts between individuals.

— Kjellberg L et al. EVJ 2025;57:54-61

Galloping Hoof Slip at Impact

Veterinarians and farriers in the U.K. examined the duration of hoof slip at impact using 13 retired racehorses exercising at a gallop at the British Racing School.

The horses were filmed at 1,000 frames per second while galloping with a marker attached to the lateral aspect of all four hooves. Horizontal and vertical positions of the hooves were recorded so the duration of horizontal hoof movement (hoof slip) after impact could be recorded. Measurements were obtained with horses shod four ways: aluminum and steel horseshoes, GluShu glue-on shoes and barefoot on both turf and artificial track surfaces.

The average hoof slip duration, about 21 milliseconds (ms), was similar for the forelimbs and nonleading hindlimbs but was shorter for the leading hindlimb (18 ms). Slip durations were 2-3½ ms longer on the turf track compared with the artificial track for all but the leading hindlimb.

In the leading hindlimb, slip duration was almost 4 ms longer with aluminum shoes compared with barefoot. In the leading forelimb, the faster the horse, the shorter the slip duration. Hoof slip is thought to impact forces transmitted to the lower limb while galloping. The authors emphasized the importance of looking at each individual limb when evaluating asymmetrical gaits like the gallop.

— Horan K et al. PLoS ONE:0311899

Castration Scars as a Cause of Lameness

Surgeons in Poland reported on the management of 33 geldings with lameness attributed to scar tissue and adhesions of spermatic cord remnants.

The horses, ranging in age from 4 to 12 years, presented for poor performance and gait problems like failure to engage the hindlimbs, reluctance to move laterally, difficulty jumping and bucking associated with exercise, specifically bucking after jumping. Orthopedic causes of lameness and poor performance were ruled out.

In about half the cases, diagnostic anesthesia of the spermatic cord remnants was helpful alerting the clinicians and the horses’ riders to the source of the problem. Surgery was performed to release scar tissue and remove adhesions and remnants of the spermatic cord that measured from 2½-9½ inches.

All clinical signs resolved following surgery in 85% of the cases. Three cases required physiotherapy of the iliopsoas muscles, one case failed to improve and one was lost to follow-up.

—  Domanska-Kruppa N et al. EVJ abstract 2024:14155