Jun 092013
 

There must be something in the air at the moment; I was recently expounding the virtues of delaying a horse’s training under the saddle only to come across an article last week on The Horse website talking about (race)horse performance at 2, 3 and 5 years related to lesions.

The cause was at that moment of little interest, the age of the horses was. Should we be riding at such immature ages?

Despite being worlds apart, the racehorse industry and the home-hack do have one main thing in common, the wish to turn their beautiful horse into a beautiful rideable horse as soon as possible. After all, most of us don’t just want to look at our horse…

There is plenty of motivation to start early too. In dressage, there is a minimum age at which a horse may compete; according to FEI regulations for international dressage competition, it is six years but for many national events, the rules are different with the minimum age being as low as three. And when one considers horse-racing, the ages are even lower – the racing of two-year-olds is quite commonplace which requires them to be saddled up for the first time when they are not much older than 1½.

For the professional trainer and owner, it is all a question of money. Often the horse is – or can become – quite valuable. Keeping a horse costs money (ironically, for the owners of such horses, it is often just a fraction of their earnings) and the natural desire is to see the horse earn its keep as soon as possible. And eventually, a racehorse can be put out to stud and earn yet more that way – these days not even needing to attain a respectable age with the ability to freeze sperm – but the health of the horse is never the greatest consideration.

So what about the mere mortals of this world? Most horse owners will agree that a horse should not be ridden until it is about 4 years old. A respectable age, one could say; the horse is obviously no longer a foal and is more likely to grow outwards than upwards. However, the growth plates are still a long way off being closed. The last plates will close somewhere between 5½ and eight years old – and it is specifically these growth plates that are found in the back of the horse – all 32 of them!

Most growth plates lie across the weight bearing plane – think of knees, ankles, shoulders etc. – and are less affected by the carriage of weight. But the growth plates in the back lie parallel to the weight bearing plane whereby the back is easily streched and thus can suffer under the weight of the rider.

skeleton of the horseTo clarify, this is the order and the approximate age at which the growth plates close up:

1. Birth: distal phalanx (coffin bone)

2. Birth and six months: middle phalanx

3. Between six months and 1 year: proximal phalanx

4. Between 8 months and 1½ years: metacarpals/metatarsals (cannon bones)

5. Between 1½ and 2½ years: carpal bones

6. Between 2 and 2½ years: radius-ulna

7. Between 2½ and 3 years: ulna/femur, section that carries weight above the radius; tibia

8. Between 3 and 3½ years: humerus; bottom part of the femur

9. Between 3 and 4 years: pelvis begins to close, beginning with the extremities of the ischium, ilium and sacrum

10. Between 3½ and 4 years: lower part (that carries weight) of the scapula (shoulderblade)

; top neck vertebrae

12. From 4 years: tarsal bones then the growth plates between fibula and tibia (not without reason that 18th century literature forbade ploughing, crossing of deep mud and jumping for young horses)

13. Between 5½ and 8 years: vertebrae (the larger the horse and the longer the neck, the longer it takes for the growth plates to close up. For stallions, add another six months: this means a “warmblood” horse of about 17hh will not be fully grown until 8 years old.)

Of course, all this does not mean that we cannot do anything with our horses until they are eight, but it should certainly set us thinking about our training schemes.

For the professional horseworld, time is loss – except the economics are not taken into account. Maybe not so interesting for the racehorse owner – his horse is often little more than a money factory – but certainly for the livery and riding school owners. In much of Europe, the average age of a riding school horse is horrifically low and the general life-expectancy shows no correlation with what a horse should (healthily) be able to reach. Based upon the size of the animal and the size and rate of its heart etc., the horse has a potential life-expectancy of 50 years. Realistically a little lower at around 40 to 43 years. But a horrific number of horses has already been written off by the age of 20 – imagine writing off people when they get to 38 or 40…

Take a look at the table below – and decide for yourself which of the two columns fits your way of thinking best:

Begin training 3 years 7 years
Full potential 7 years 10 years
End “useful” life 18 years 35 years
Total work period 15 years? 25 years

Just by delaying the moment we start to ride by just 3 years, we can win 10 years in “useful” life. It makes you think…

 

Growth plate information: Timing and rate of skeletal maturation in horses, Dr Deb Bennett, 2005
“Useful Life” table: based on observations by Pierre Enoff, bio-mechanical engineer
Original article published in Dutch: http://www.kobolt.nl/gezondheid/leeftijd-bij-inrijden/   https://sabots-libres.eu/site/engagement/2013/leeftijd-bij-inrijden/