Are greyhounds right- or left-handed and, if so, how did they get that way, how many are there and what does it mean for racing enthusiasts? My interest was piqued in late September by a Sydney Morning Herald article which reported on research published in Nature Human Behaviour.
It suggested that human left handers accounted for perhaps 10% to 15% of the population but that only 25% of the reason for handedness was genetic, whether humans or animals generally.
The rest was either unknown or due to environmental issues, both past and present. However, all researchers noted that it was difficult to be certain about any numbers due to the varying circumstances in place in any research project.
So be it, but I will return later to probable impacts on greyhounds.
In practice, definitive research on greyhound handedness is limited. One exception is a paper titled “Injuries in racing greyhounds” by Andrew Knight from the University of Winchester, in conjunction with the QIMR Institute at the University of Queensland and the NZ Racing Integrity Unit.
As the title indicates, the paper mentioned handedness quite a lot but always in connection with the location of injuries and where and why they might have occurred on the track – much of it obvious ….
“Tracks of a larger radius, and steeper banking (camber) of curves, both reduce the degree to which greyhounds need to “lean” inwards during cornering”.
Or, from another angle ….
“Risks increase when locomotory forces increase, eg when rounding bends, or when biomechanical limits are lowered, eg in young bones, or following bony remodelling …”.
In the last case, the author is referring to the greyhound’s body developing stronger attributes in certain areas such as the side nearest the rail where the highest pressure is observed during racing. Nature notes the location of the stress and ensures compensating bone or muscle growth.
Indeed, separate but related NZ research has involved long term x-ray checks of greyhounds from pups to mature racers. That identified a high number of hairline bone cracks in youngsters which then posed a risk of more serious injury later in life – ie broken hocks, etc. The researcher (a scientist-cum vet) put this down to the constant pattern of training and racing in an anticlockwise direction.
This was also consistent with Knight’s finding (about British injuries) that “these tarsal bone fractures are thought to be fatigue fractures resulting from repetitive loading during training and racing (as) propulsive forces during cornering whilst running anticlockwise result in the right hind limb being the most affected”.
A 2017 British injury survey found that the most common injury location, as a percentage of total runs, were Hind limb muscle (0.26%), Hock (0.20%) and foot (0.20%).
Moving on to right and left tendencies, Warren (Physiological Psychology, 1980), notes that “the proportion of left-handed students in the United States increased from 2% in 1930 to about 11% in 1970, largely because of the greater tolerance of left-handed persons by teachers”. Nature overcame nurture.
Even so, his claim of equal distribution of handedness in animals has been bypassed by later studies, one of which offered these surprising examples of right preference in primates (Hopkins, Georgia State University):
- Chimpanzees – about 65-70 per cent.
- Gorillas – about 75 per cent
- Orangutans – 34% per cent.
Other studies have identified substantial lateralisation in many animals and birds, some of which has paid more attention to the influence of neural pathways – pointing out that the left side of the brain “seems to process and control feeding” and so on.
In other words, some combination of genetics and individual brain control are the primary influences in animals of right or left handedness but the precise numbers are still open to debate. Certainly humans can be a puzzle, too. Rafael Nadal has a mighty left forehand but writes and throws with his right. Many cricketers bat right and bowl with the left, and vice versa. Then Dave Warner has hit sixes from either side of the crease. Baseball has some fantastic switch hitters who choose their side according to the pitchers they will be facing. My own periodic checks of greyhound preferences suggest a number of options.
While a basic tendency may be to Rail or run Wide (perhaps 10-15% Wide), there are also middle (of the track) runners as well as those which desperately crash to the rail or veer quickly to the outside of the track after jumping. Other normally wide runners may run wide in the straight but rail around the turn. Others change a little with experience.
So how important is it to study these practices more closely?
First and most important, tracks must be designed to best suit the majority of runners – by maximising turn radius and camber, and eliminating more dangerous bend starts.
A side issue here is that one researcher recommended that more or most races should be over straight tracks – without any corners. (The upcoming new Traralgon J-track partly goes down that road). This was also a suggestion from UTS in its interim report to GRNSW. Since UTS has no particular expertise in racing greyhounds it may have used the same source to justify that claim. In practice, such an option would have the effect of strangling the very versatility of the code and the breed. Like the curate’s egg, it would be good in parts.
Second, stresses posed by constant anticlockwise education, training and racing pose obvious risks. It suggests developing means to vary exercise offered to youngsters in particular.
Third, all these points emphasise welfare shortcomings even more important than euthanasia inasmuch as they affect all dogs, not just a few.
Fourth, more intelligence about handedness can only aid our knowledge about how dogs race and how to better assess betting opportunities.
Fifth, along those lines it seems clear that dogs with left hind leg dominance will tend to push wide on the track while those with a stronger right hind leg will want to move over to the rail.
Whatever, more work – serious and transparent work – is needed to push the industry forward. Comments should be sought widely.
*Quotes and concepts here were gleaned from Nature Human Behaviour, The Humane Society Institute for Science and Policy, Physiology Psychology, Science Friday, New Scientist and other references.