Hoof & Lower Limb Soundness
Category: Horse Health
Kate Hore RNutr(Animal). Senior Nutritionist at NAF
Well summer of 2018 has proven to be a hot and dry one, and while we’ve all enjoyed basking in some sunshine, there are some less desirable consequences for our horses. Of particular relevance to farriers is the extremely hard ground conditions, extending for much longer periods of time than we’re used to, and what long term consequences that may cause.
It’s understood that different weather conditions are likely to affect rate of hoof horn growth, as certainly we see seasonal differences between summer and winter. However seasonal differences shouldn’t simply be attributed to weather, as horse’s management often differs between seasons also. But one thing we can be sure of, is that working on hard ground will have an impact – quite literally – on the concussive forces going through the hoof wall and on up the limbs. It is calculated that around four tonnes of concussive force go through the lower limbs of horses when galloping, but this will vary with many factors including weight of the horse, speed and, crucially, the surface. The hard surfaces we’ve seen this summer can only increase potentially damaging concussion.
The horse’s hoof is uniquely adapted to absorb and spread much of that concussion. As we know, the horse does not stand in his shoes, but rather is suspended in the hoof capsule by the lamellar distal phalangeal attachment. For the front limbs, taking 60% of the weight bearing, this suspension approach continues up to the top where the shoulder is attached by the muscles and ligaments of the thoracic sling, which allows greater absorption of concussion than a bony joint would. The hind limb takes less concussive forces, however those will travel up to the spine via bony joints all the way, so protecting the horse from excess concussion is important all round.
So what can we do to help, both from the outside and from within?
Firstly let’s consider trimming and the horse’s hoof. The Equus family are unique in that they are the only hooved animals that have evolved with a single toe. This makes them fast and athletic, but relatively delicate. Weight bearing occurs primarily down and around the hoof wall. The hoof wall is anisotropic, meaning the strength differs in different directions. The hooves reaction to hoof compression or concussion is to adapt and change as it grows in a plastic way, thus the wall may be pushed out resulting in permanent changes in the shape of the hoof. This explains how while foals are born with beautifully symmetrical hooves, we may see significantly differently shaped hooves quite quickly due to one side suffering more compression than the other.
Trimming can have a significant effect on weight bearing. Even mild or short term changes in hoof balance can have a significant effect on where and how evenly concussive forces are absorbed. Therefore if mediolateral imbalance persists over time it’s easy to see how issues such as joint stress may occur. Trimming to encourage correct limb alignment will have a beneficial effect on all the joints of the leg.
Whether to shoe or not will also have a bearing. Research suggests hoof morphology, particularly the depth of the digital cushion, may be improved by leaving the horse barefoot, so why not consider suggesting shoe free for those that it suits?
Once we have a strong, even, outer wall if we can also support from within then we are giving the horse the best chance to cope with hard ground and maintain soundness. So how can nutrition help joint health? If we just consider the hoof itself, we have the Coffin joint and Navicular bone entirely within the capsule, both areas where degenerative joint disease may be diagnosed. Extending that upwards, with a total of eighty bones in the four limbs, all interacting at various complex joints, we can see the potential for problems and how feeding to support joint health may help you, as farriers, maintain sound horses by feeding for strength from within.
One of the best-known ingredients for joints, glucosamine is an important building block of joint tissue, making it an important joint nutrient from growth right through a horse’s career. Look out for Glucosamine sulphate, which scientific research shows is the preferable form to feed for equine joint health. This may be, at least partly, due to bioavailability, and certainly evidence in horses shows the sulphate form to be more bioavailable when fed compared to other forms.
MSM is an organic compound rich in sulphur, an important element in joint integrity. Trials on MSM in both people and animals have shown reduced pain and inflammation when taken for joint health. MSM is found naturally, in low levels, in plants but is quickly lost when processing or storing feed. Therefore, particularly in a summer such as we’ve had with limited fresh grass, horses’ diets benefit from the addition of MSM.
Chondroitin sulphate and H.A. are both glycosaminoglycans (GAGs), meaning building blocks of cartilage and joint tissue. They are relatively large compounds, and bioavailability in horses is not well established. It’s thought that their precursor, glucosamine, is the more important ingredient for horses. However there is evidence that they have a role in equine joint health, particularly when fed in combination with other joint nutrients.
Finally it is recommended to ensure that natural antioxidants are also included in any joint nutrition programme, in order to support the body’s own anti-inflammatory defences.
Joints are complex structures and so no single ingredient can support all areas. Look for a quality joint supplement from a company you trust which combines the key ingredients above in a synergistic blend. If customers are competing, don’t forget to advise they also check the product chosen carries the BETA NOPS accredited mark, which ensures it’s safety credentials for all performance horses.
In conclusion, our horse’s hooves will be working harder than ever to cope with this year’s hard ground; but through good hoof management from farriers, and nutritional support from owners, we can help horses maintain soundness both now and on into whatever weather the winter has in store for us!
This article has been written and supplied by NAF, our thanks to them -