in the veterinary world?
There’s a new formula that can determine a horse’s age, and stress has been linked with poor results
LONG IN THE TOOTH
THE shape, marks and angles of the incisor teeth can really only give a reliable indication of a horse’s age up to about six years old. After that, it becomes an informed guess.
Certainly, the teeth can suggest that a horse is young (perhaps under 10), mature (maybe in his teens), or old (20-plus), but no one can open up the mouth of a horse and guarantee that he is 12, 10 or even eight years old.
Vets in Canada and the
USA have compared CT scans of the head of their equine patients with known ages from the horses’ passports. They looked at the CT scans of 735 horses and ponies and carefully measured the complete length of the first molar tooth, M1, which is the oldest tooth in an adult horse.
The scientists found that they could age a horse pretty accurately using a formula: age in years = 30.11 – (4.56 x crown height of M1 in mm) + (0.12 x crown height in mm).
Simple correction factors for sex and breed that need applying to reach the final result have been worked out — for example, adding 1.18 years to the answer for females and subtracting 1.67 for ponies.
The next step will be to see if the same system can be used on X-rays, which are far simpler and safer to take than CT scans.
RACEDAY STRESS
SPANISH vets have analysed stress levels in racing trotters and confirmed that while some stress is good for performance, too much is associated with poor racing results.
They measured eyeball temperature with a thermal scanner and heart rates with a simple pulsometer. Eyeball temperature is known to be a good indicator of stress.
The vets found a strong correlation between the actual eyeball temperature before racing, the increase in eyeball temperature during a race and the horse’s racing performance.
Horses already stressed before racing had no increase in eyeball temperature as they raced. Horses performed best when their eyeball temperature was no greater than 37.61°C before the race and then increased by about 7.5% during the race.
Because horses are adapted as flight animals, some level of stress can be beneficial for explosive exercise such as racing. If they get too worked up before starting to run, however, other metabolic and physiological factors come into play and their speed and performance is reduced.
We have known this by experience and observation, but research like this shows that we can measure it objectively and perhaps predict performance.