Guarded Prognosis for Navicular Bursa Masses

Veterinarians in the United Kingdom evaluated the records of 59 horses (mostly Irish sport horses and warmbloods) with lameness that were examined with magnetic resonance imaging (MRI), found to have a synovial mass on the dorsal aspect of the deep digital flexor tendon (DDFT) in the navicular bursa and subsequently underwent bursography (endoscopy of the bursa).

They were interested in the correlation between the MRI images and what they found at surgery and if the prognosis for returning to performance was related to the size of these masses, which are described as clumps of collagenous tissue extruding from DDFT lesions into the bursa.

There was a strong correlation between the sizes of the lesions and masses seen on MRI and during surgery. However, there was little association between the sizes of the lesions or the masses and the outcome of returning to the patients’ previous levels of exercise. Following surgical removal of the masses, only 30% of the horses returned to their previous level of work, a prognosis the authors regard as worse than previously reported.

— Giorio ME et al. EVJ 2023:14040

Obesity in Irish Ponies

From the veterinary school in Dublin, researchers surveyed 200 Connemara ponies to determine the prevalence of obesity, related metabolic diseases and laminitis and investigate whether insulin dysregulation and laminitis could be predicted from measures of obesity.

Owners completed a questionnaire and the ponies were examined to record body condition (BCS, 1-9 Henneke scale) and cresty neck (0-5 scale) scores and localized fat deposits (adiposity). Blood samples were tested for glucose, insulin, triglycerides and other measures of metabolic function.

Ponies ranged from 5 to 26 years of age, most (68%) were female and, interestingly, half were described as intensively managed sport ponies and half were managed in a mostly free-ranging, pasture environment with little human interaction.

Most (68%) of the ponies had either a BCS ≥ 7, cresty neck score ≥ 2.5, or localized adiposity (68%). About half (46%) of the ponies either had signs of chronic laminitis (41%) and/or a history of laminitis (12.5%) reported by the owners.

Surprisingly, baseline indicators of metabolic dysfunction were not common with high insulin (16%), glucose (6%) and triglyceride (6%) levels recorded. Insulin dysregulation, affecting 25% of the ponies overall, was significantly more common (odds were 6.5 times greater) among ponies with a BCS ≥ 7. 

Unfortunately, understanding the effects of intensive versus free-range management on the factors studied will require future, larger studies.

— Al-Ansari AS et al. EVJ 2024;56:273-280

Chiropractic Treatment Improves the Ride

Veterinarians at Pennsylvania’s New Bolton Center conducted a blinded controlled trial with 27 sound hunter-jumpers to determine whether chiropractic treatments affected stride rate, length and symmetry, as well as heart rate and the rider’s perception of a horse’s ridden work.

These parameters were assessed before and 2 days after either chiropractic treatment or a sham treatment that simply included petting the horse over the neck and back and, importantly, those evaluating the outcomes were unaware of when horses received the actual treatment or the placebo. Horses were fitted with a fitness tracker and ridden by their normal riders at a walk trot and canter after which the riders were asked whether the treatment had a positive, negative, or neutral effect on the quality of the work.

Following the chiropractic treatment, 83% of riders reported improvement while after the sham treatment, only 11% reported improvement. This indicates a significant effect of the treatment on the rider’s perception of the horse’s performance. 

Surprisingly, none of the quantitative parameters measured showed any differences before and after treatment. The authors suggest that either the variables selected or the instrumentation used may not have enough sensitivity to detect treatment effects if they occurred in these sound horses. These results suggest chiropractic treatments deserve more consideration and study as a means of improving athletic performance.

— Lorello O et al. EVJ 2024:14043

Senior Horses, Retirement and Muscle Mass

A collaborative group of scientists from Kentucky, Texas and the United Kingdom surveyed 2,717 owners of horses ≥ 15 years of age to examine how senior horses are used, the reasons they are retired, how they are exercised and the prevalence, causes and impacts of low muscle mass, usually noted over the back and rump as reported by the owners.

About 40% of the horses in the study were fully retired and about 38% were in use for pleasure riding or driving. Use for breeding was the most common reason for horses being retired at less than 10 years of age, but health problems were the primary reason for retirement in all other age groups with degenerative suspensory ligament desmitis, laminitis and lameness most significant.

Thoroughbreds were more likely to be retired compared with other breeds. Owners reported that 17% of the horses in the study had low muscle mass and they commonly felt this impacted the horses’ welfare and ability to work. Older horses, geldings, those that were retired and those that had Cushing’s disease, arthritis and laminitis were more likely to be retired.

— Herbst AC et al. EVJ 2023:13958