Genetically Weak Feet?
© Anya Lavender.
Why this doesn't hold much water with me
"Typical Thoroughbred feet" ... "We have bred the feet off domestic horses" ... "Inherited flat feet" ... "White/striped hooves are inherently weak" ...
We have all heard these statements, often believed them... what is the truth behind them?
Firstly, to be clear, there are indeed genetic factors at work, I am not discounting that. Certain breeds or types are more likely to 'go splat', like Thoroughbreds, whereas others are 'prone' to growing high & boxy like ponies and Quarter Horses for eg, when under the same conditions. Arabs, draft horses and Standardbreds are among breeds which naturally seem to start with a stronger caudal foot than many others. And we have indeed bred some Quarter Horses with such 'dainty' feet as to be problematic, or particularly 'thin skinned'(so thin hoofed) Thoroughbreds for eg. On top of that, as in all species, there are odd deformities or deficiencies which may be genetic.
But in ALL cases, it is management / environmental factors which make the BIG differences and in the vast majority of situations, genetics plays but a very small part. With the right management, Thoroughbreds will indeed grow strong, thick concave hooves, Quarter Horses and ponies can grow low, robust heels... etc.
Likewise, Brumbies, Mustang and other feral horses can just as easily 'go splat' with unhealthy environmental factors. Therefore the assumption that we have 'bred the feet off the domestics' while feral hooves are genetically stronger also appears unfounded.
These 'good' or 'bad' hooves are MADE, not bred! However, it takes more than just good hoofcare to create them. It is about their whole diet, management and environment.
On the note of white/striped hooves being weaker, this myth still abounds! Apparently it gained popularity, after early observations of Native American preferences for dark hooves, by anthropologists and explorers(not biologists or even those particularly studying horses) were reported and assumed to be due to hoof strength. Although interestingly it was also noted that spotted and dappled horses – which usually had bi-coloured feet – were also greatly coveted by the Plains Indians, and if their hoof strength was inferior, why would they value these horses so highly?
Anecdotal stories have abounded since, but as usual, environmental factors are huge and mostly unstudied factors on hoof health until recent years. Researchers in the field and laboratory have included Jaime Jackson, Dr Doug Leach, JE Douglas et al, and Runciman et al. There have also been studies done on bovine and ovine hooves, with the same results. None of these studies has shown a difference in tensile or compressive strength, nail retention or abrasion resistance between pigmented and unpigmented horn.
These studies, combined with my own and other's experience lead me to believe there is absolutely nothing in the 'white hooves are weaker' story. What I surmise is often observed and assumed to be evidence for the 'weak white' theory is that in unpigmented horn, damage can be seen far more clearly. You can see infection under shallow cracks and you can see bruising, or red rings from a 'laminitis episode', whereas they are difficult or impossible to see through pigmented horn. This has led to the assumption the damage was not there in dark horn. This is just not the case, if you look at what lies beneath however.
On the note of inherited 'club' feet, it is of course possible that genetic deformity could be a cause of this. But anecdotal stories of foals born with a club foot, to a club footed mare or stallion have led to assumptions about genetic cause. However, here are some other factors we can consider; Animals tend to be 'one sided' such as humans are right or left handed, so the commonly trailing foot, in a long legged animal grazing at ground level has far less pressure and wear on the heel, so it tends to become more upright. The nature in which foals sit 'in utero', and are birthed commonly leads to injuries and asymmetries which cause lateral imbalances to the hoof. And if innate genetic structural abnormalities were the common cause, then 'treatment' such as bodywork and feeding hay at wither height, which are often successful would be unlikely to have noticeable effects on hoof symmetry from one forefoot to another. Therefore I think it is highly unlikely that the vast majority of cases of 'clubbed foot', or 'High-Low Syndrome' as it is being recently called, are genetic in origin. Again, environmental factors are the likeliest culprit.
Before we jump to blame the scapegoat of genetics for the myriad of hoof problems, we need to first rule out all the environmental causes.
Almost regardless of genetic factors, hooves can be improved or brought to strong, sound health through means of hoofcare, diet and lifestyle changes!