Asymmetry In Polo Horses In the United Kingdom, researchers examined movement asymmetry in-hand at the trot in 60 polo horses using wireless inertial measurement devices attached to the poll and pelvis. The horses were selected from those actively in training at three different operations.

Researchers studied the specific lamellar pathology associated with laminitis caused by equine Cushing’s disease, also called pituitary pars intermedia dysfunction (PPID). Hooves of 26 horses and ponies were collected following euthanasia or processing for slaughter and divided into those with signs of PPID and laminitis, those with PPID and no clinical signs of laminitis and controls with no clinical signs of PPID or laminitis. Hoof tissues were examined microscopically and circulating insulin, cortisol and glucose were measured.

A postmortem study examined the records of 241 horses at least 15 years old that died following admission to a veterinary teaching hospital over a 10-year period to investigate their causes of death, including the relationship to pituitary pars intermedia dysfunction (PPID).

Conference Short Highlights The American College of Veterinary Internal Medicine recently published several abstracts of their annual meeting related to two endocrine disorders:

Joint Injections Compared Joint injections using corticosteroids, hyaluronic acid (HA) or a combination of the two are commonly used to treat synovitis and arthritis in performance horses. In this study, researchers compared the efficacy of one type of corticosteroid (triamcinolone acetate, TA) with and without HA for the treatment of lameness, localized to one limb only that responded to a diagnostic joint block. Eighty horses of various breeds were enrolled in the study with follow-up at 3 weeks by re-examining the horses and 3 months by an owner questionnaire. No other medications were permitted during the first 3 weeks of follow-up.

IV Tildren for Navicular Syndrome The efficacy of administering the injectable bisphosphonate medication for horses (Tildren) in two different ways was evaluated for the treatment of navicular syndrome. Twelve horses diagnosed with bilateral navicular syndrome were randomly assigned to receive Tildren either systemically by intravenous injection or by using regional limb perfusion, where the drug is “back-flushed” directly into the blood vessels of the lower limb so that it is delivered to the lower limb and hoof in a more direct, concentrated manner.

Researchers in Canada used cadaver limbs to study the effects of hoof angles and loading patterns on joint surface contact areas in the fetlock. Eight limbs from Standardbred horses that died for reasons unrelated to this study were fitted into a mechanical pendulum device to simulate hoof strike at a trot. Strips of pressure-sensitive film were placed across the joint surfaces inside the fetlock to measure contact areas, and the limb was loaded while simulating flat, toe-first and heel-first landings.

Hoof Balance Of Toed-In Horses

Veterinarians in Belgium examined the dorsopalmar and mediolateral hoof balance of five toed-in warmbloods that weren’t lame at the time of the study. They used a pressure plate to assess the symmetry of vertical ground reaction forces as a measure of hoof balance and limb loading symmetry at a walk. Their hypothesis was that toed-in conformation primarily affects mediolateral balance.

This investigation examined hoof tissues from horses affected by pituitary pars intermedia dysfunction (PPID or Cushing’s disease) with the hypothesis that pathologic changes consistent with laminitis would be found whether or not the animals showed clinical signs of laminitis. Tissues from 26 horses were examined including PPID affected horses with and without laminitis and controls. The length, width and appearance of primary and secondary epidermal lamellae were compared between the affected and the control horses.

An experimental study with 22 ponies was conducted to investigate the effects of feeding a diet high in nonstructural carbohydrates (starch) on the laminae of lean ponies compared with obese ponies. The ponies were sorted into lean (body condition ≤4) and obese (body condition ≥7) groups and half of each group was fed either a low starch hay diet or a high starch diet with added sweet feed and plant sugars. After 7 days, laminar tissue samples were collected and analyzed to measure the activity of naturally occurring substances that trigger inflammation (inflammatory mediators) and the expression of genes that control inflammation.