Every time you saddle a horse, you tighten a girth. But how tight should you make that girth? Just enough to keep the saddle on? With space to slip a hand under the girth? As tight as it will go? Furthermore, how well does a horse breathe with this tight band strapped around his lungs?

John Bowers, BVSc, MACVSc, and Ron F. Slocombe, BVSc, MS, PhD, Dipl. ACVP, Chair of Veterinary Pathology at the University of Melbourne, Victoria, Australia, recently investigated this question in a study involving eight ex-racehorses. They found that most grooms in the Australian racing industry tighten the girths to a point that could have a detrimental effect on their charges’ performance.


Studies with humans have shown that tight strapping of the chest can relieve shortness of breath at rest in patients with chronic obstructive airway disease, such as emphysema. However, this strapping impaired patients’ ability to exercise. No previous studies had been done with horses, but anecdotal evidence suggested that the same was true for horses–that a tight strap around the chest decreases performance.

Several racehorse trainers in Victoria believed this to be true because their animals had performed poorly after their saddle girths had been over-tightened just prior to racing.

To set a baseline for their study, Bowers and Slocombe measured typical girth tightness at several racing stables around Melbourne. They found that the usual tension applied to keep a saddle on a Thoroughbred racehorse is 13 kilograms (kg) (29 pounds).

Methods And Results

Ten former racehorses purchas