The amount of bone needed is dictated by the mass it must support. The finer boned Thoroughbreds which have been bred to race for centuries actually tend to have denser, stronger bone than horses that have been bred for other purposes and the big bones can be soft and porous, leading to injuries. It’s long been a “buzz” word for stallion owners trying to market their stallions - using the circumference of their cannon bone as hype – which is BS. The injuries many Thoroughbred suffer is because of racing too early on structures that are still forming and soft. You don’t get stress fractures or bucked shins unless you are doing fast work. Crooked legs or conformational issues would also factor in on racing or sport horses and how well they stand up to work. Arabians do endurance runs on uneven ground and their fine, flinty legs that hold up beautifully! Alot of bone is utter nonsense – it is about proportion.
PennyG
i don’t know if this has been outdated but it used to be eight inches/1000lb was adequate. bone is actually part of our breed standard so the way in which we interpret that is that 7 (the minimum for our breed standard) might be sufficient on 13.2 but is insufficient on 14.2 and over. I have actually gone out and measure the bone on my own and was interested to see that that the 12.3 welsh had about as much bone as some of the 14.2HH. The most bone was on the 17.2HH.
I just read this:
https://rirdc.infoservices.com.au/downloads/00-001
The effects of age and exercise on shape and volumes of the navicular bone were studied by Gabriel et al. (1999). All the external measurements of the navicular bone decreased significantly with increasing age. However, in sporting horses, the navicular cortical bone volume increased with age and the cancellous bone volume decreased. Exercise appeared to have decreased bone resorption and increased bone formation. The findings confirmed that exercise might be good practice to prevent age-related bone loss in horses.
