Hoof care is of paramount importance to a horse’s health. No foot, no horse.
Finding a farrier
There are many farriers around and they all have different levels of experience and expertise. There’s more to the job than just correcting the foot. A farrier also needs to have good animal handling skills, preferably have a click with your horse and have good communication skills. If you’re new in an area there are usually people around that can help you find a farrier or give you someone’s contact details, but what works for one person or horse might not work for someone else. If you are looking for a farrier, we can help you get in touch with several farriers so that you can find a farrier you like.
Hoof growth and trimming
A horse’s hoof grows about a whole length in a year. However, hoof growth varies between animals and seasons and can be influenced by many things. In summer feet tend to grow a bit faster than in wintertime due to changes in nutrient availability, temperature, moisture, etc. How fast the hoof grows affects how often it needs to be trimmed. Additionally, if a horse has certain conformational problems or poor hoof quality, it may need to be seen by a farrier more frequently (every 3-4 weeks) to correct the situation and prevent deterioration. However, in general, horses with healthy feet usually get trimmed about every 6-8 weeks. When feet become too long, the angles of the feet change which affects the joints, ligaments and tendons. Longer hooves also tend to chip and split, creating access for dirt, bacteria and fungi associated with hoof abscesses, crumbling hoof horn and white line disease.
Hoof quality
Nutrition and regular care by a farrier are the most important things for strong and healthy hooves. If the quality of the horn itself isn’t good (cracks, brittle feet that chip easily, etc), it pays to have your horse’s overall diet evaluated before resorting to a targeted supplement. Poor nutrition may be the cause, which means that a hoof supplement is only going to solve the part of the problem that is visible in the feet. The horse’s feet may be an indication that the diet is lacking nutrients necessary for other body tissues as well, which may be less easily recognized.
Energy requirements
A horse in a negative energy balance will utilize its proteins to generate energy for maintenance, performance or growth. This means that these proteins may become depleted and are no longer available for growing good quality hoof tissue. Studies have shown that hoof wall growth was 50% greater in growing ponies that were in positive energy balance than in ponies on restricted diets with reduced body growth rate. It is a common observation that in summer, when pastures are lush, hoof growth is faster than when horses are grazed on poor pastures. However, energy balance is not the only important thing for strong feet and simply feeding more is therefore not always the right solution.
Vitamins
Biotin is a B vitamin, which is normally produced by the microflora of the hindgut. A horse therefore doesn’t usually need biotin in its feed if it’s eating adequate amounts of fibre. However, an additional daily dosis of biotin has shown to improve the hoof quality of horses with hooves that crack and chip easily. Biotin plays a part in fat- and protein metabolism and in cellgrowth. It has a positive effect on the development of horn- and skincells. Studies have shown that a daily dose of 15-30mg of biotin can improve bad hoof quality. However, this does not happen for every horse with bad hooves, and because hoof growth is very slow, biotin needs to be supplemented for at least 9-15 months to determine whether there is a positive effect. If there is, it is likely that a horse will need lifelong supplementation to maintain improved hoof quality. A study on biotin supplementation showed that of those horses that reached improved hoof horn quality, hoof horn condition deteriorated in seven of 10 horses after biotin supplementation was reduced or terminated.
Vitamin A (retinol) is important for the integrity of epithelial tissues, bone development and vision. It is mainly supplied by fresh grass but is usually also incorporated in vitamin/mineral feeds. A true vitamin A deficiency (which is very rare) causes issues of the coronary band (and many other issues), which influences hoof growth. If your horse is on a good diet, it should not be needing any supplemental vitamin A. This again shows the importance of checking a horse’s daily nutrition before resorting to any hoof-specific supplement.
Proteins and amino acids
When it comes to proteins that are needed to build strong and healthy hooves, it is important that your horse gets the right amino acids, not just any. There are 20 different amino-acids, of which the horse can make 11 amino-acids by itself. The other 9 are what we call “essential” amino-acids. Horses can’t make them, so it’s essential for the horse to receive them through the diet. When an essential amino-acid is missing, the entire production of a protein can’t go through, even if there’s a lot of other amino-acids available. You might be feeding your horse lots of protein/amino-acids, but as long as there’s not enough essential amino-acids to complete the picture, the other amino-acids would just be lost unused. It is therefore important that a horse receives enough high-quality proteins to supply the horse with the right amino-acids to build strong tissues.
The hoof wall is composed of about 93% protein on a dry matter basis. It is primarily made of the protein ‘keratin’. The body can use the amino acid ‘metionine’ to make cystine, which is essential in the production of keratin and the formation of cross-links between cells. These cross-links are essential for healthy collagen and strong tissues (skin, hair, hooves, cartilage, etc). For this reason, many hoof supplements contain methionine to stimulate growth of a healthy hoof wall. However, the hoof wall is only a part of the hoof, and methionine is just one of the amino acids that make up a healthy foot. The entire hoof contains high levels of cystine, arginine, leucine, proline, lysine, serine, glycine, and valine, and it contains lower levels of methionine, phenylalanine and histidine. You can see how deficiencies of any essential amino acid can lead to bad hoof quality. Studies have shown that 1) normal hoof horn proteins contained higher levels of threonine, phenylalanine, and proline and lower levels of arginine compared to poor-quality horn, and 2) protein-deficient diets lead to reduced hoof growth and splitting and cracking of the hoof.
Minerals
Zinc has an important immune-modulatory role and affects growth and tissue integrity. A deficiency has been proven to result in decreased immune function and hypersensitivities, reduced growth rate in young horses and skin lesions. Noormohammady et al (2018) concluded that zinc doesn’t have a determining effect in structure of hoof horn, but that it’s likely that zinc improves keratin production and quality. Ott and Johnson (2001) concluded that supplementing the diet with zinc can increase the growth rate of hoof horn but not necessarily its integrity. Hoof supplements therefore often contain zinc to potentially benefit hoof wall quality.
Calcium is important for many bodily functions and tissue structures. Calcium also has an important role in keeping healthy hooves. The body needs calcium for many things, amongst which is the formation of cross-links between cells (‘desmosomes’) that give tissues their strength. Calcium therefore has a primary role in the hoof structure by forming these cross-links between the individual layers of the hoof wall, which gives hooves their strength. With a calcium deficiency, the connection between the layers of the hoof wall becomes compromised, resulting in loss of hoof wall strength and defects that allow penetration of bacteria and fungi associated with crumbling hoof horn and White Line Disease. A calcium deficiency can be caused by low calcium levels or high levels of phosphorus in the diet. Calcium and phosphorus need to have the right ratio (between 1:1 and 3:1) in the diet because an excess amount of phosphorus blocks calcium uptake in the small intestine. Especially horses on high grain diets may be affected. Grains, especially bran, contain phytate which is high in phosphorus. A study by Susan Kempson et al (1987) looked at the effect of supplemental biotin in horses with brittle hooves. The horses were fed bran or oats (high in phosphorus) and chaff or grass hay. The biotin did not improve the feet, but when alfalfa was added to the diet, hoof health increased in the majority of horses. Alfalfa is high in calcium and protein, which are both important for healthy hooves.
Selenium is important for a horse’s immune function and health. The Manawatu area is known for low selenium levels in grass, which is why most people are mostly concerned for deficiencies. However, it is just as important that horses are not over-supplemented. Sulphur is required to build the cross-links necessary for healthy and strong hoof horn. Excess selenium takes sulphur’s place in these cross-links, creating a weak hoof structure. Visible signs include prominent horizontal hoof wall ridges or cracks, a “crusty” coronary band, and hoof wall invasion by bacteria and fungi.
If your horse has poor hoof quality, the first step is to have your horse’s diet reviewed and deficiencies corrected. Additionally, your horse may benefit from a biotin supplement.
Moisture
The horse’s hoof wall is made up of different layers. The outer layer’s primary function is structural support and maintaining the right level of moisture. Too much or too little moisture would undermine structural strength. Hoof wall samples from feral horses living in different climates (dry to wet) have shown that hoof wall moisture content was nearly identical, averaging 29.5%. The moisture content of the hoof (wall, sole, frog) is controlled by the internal circulation, which is fairly constant in the healthy horse. Soaking dry hooves in water doesn’t affect the moisture content of the hoof wall. Instead, it affects the sole. When the moisture content of the sole goes up too much, it becomes weak and vulnerable to bruising and damage. There are many products that claim to ‘lock in moisture’ when applied to the hoof wall. However, research has not yet been able to prove this.
Cracks
Hoof cracks can be minor to severe. Their cause, depth, length and location can vary. A crack can become infected and/or cause lameness. If a minor crack is left untreated, the pressures and shocks that the feet absorb every day can cause a crack to split further and cause lameness. Treatment depends on the cause and severity, but usually involves good nutrition and proper care by a farrier. A farrier may use a variety of techniques to prevent a crack from getting worse, such as: notching the upper limit of the crack; reducing hoof wall length a bit at the crack site to reduce the pressure around the crack; stabilising the crack with clips/screws/wire sutures; applying hoof repair materials (fibreglass/epoxy resins/acrylics); special shoeing. All of these techniques have their advantages and disadvantages, and a farrier’s choice may also depend on the materials and experience he/she has.
Angles
Hoof angles are very important in keeping horses sound. The hoof-pastern axis should be the first guideline when trimming the foot. When viewed from the side, with the horse’s cannon perpendicular to the ground, the hoof-pastern axis should form a straight line. When this is the case, an imaginary straight line passes through the middle of the pastern and coffin bone from the fetlock joint to the ground. This way, the solar surface of the coffin bone is relatively parallel to the ground.
Some people find it easier to draw an imaginary line over the front surface of the pastern and the front surface of the foot when viewed from the side, instead of the internal structures.
When the hoof-pastern axis is not right, this can either be due to excessive toe length and/ or low or underrun heels (broken back hoof-pastern axis), or by upright or clubfeet (broken forward hoof-pastern axis). A broken back or forward hoof-pastern axis affects shock absorption capacity at landing and puts higher stresses on tendons, ligaments and joints. This can lead to lameness and structural damage.
The second important thing that the left and right side of the hoof are balanced. The heels should be equally long. Uneven heels (sheared heels) often occur in conjunction with other hoof conditions, such as heel and quarter cracks and contracted (narrow and often high) heels. Improper hoof balance can predispose a horse to developing sheared heels, but improper hoof balance itself can be caused by many things. If you want to assess your horse’s heels, make sure your horse stands square on a flat surface and look at a horse’s hoof from the rear. The coronary band should be level as it follows the curvature of the heel on one side compared to the other, and the distance from the coronary band to the ground should be the same. Underrun heels (described as long-toed and low-heeled) is another issue that’s frequently encountered. If a horse merely has a low heel, but the structures of the heel (the hoof wall, the bars, and the angle of the sole) are not damaged, then the heels are not ‘underrun’. Truly underrun heels can be difficult to correct and need time to do so under the care of a good farrier.
When looking at the solar surface of the foot, draw a line from left to right through the widest part of the foot. The distance from this line to the toe and to the base of the frog should be equal. When looking at the solar surface of the foot, the hoof wall at the heel should not start further forwards than the widest part of the frog. The frog has a role in shock absorption, support of the soft tissues inside the foot, transferring forces onto the digital cushion for proprioception, and many other things. The frog should be well developed, not be lower than the solar surface of the hoof wall and not higher either (it should just touch the ground when standing on a flat surface).
When looking at the hoof from the front, the hoof wall should slope towards the ground evenly on both sides without flaring in or out.
When the horse’s foot lands on the ground, the hoof wall should touch the ground at the same time all the way around. If the inside or outside lands first, the foot may not be trimmed properly.
These descriptions are meant as a guideline. If your horse’s feet diverge from these descriptions, please consult a professional to see whether there is a problem.
If you have any questions about this article or about your horse’s feet, please feel free to contact us. Our vets would be happy to help you out.
Resources:
Kempson et al 1987. Scanning electron microscope observations of hoof horn from horses with brittle feet. Veterinary Record 120:568-570.
Ley et al. 1998. Effects of season and diet on tensile strength and mineral content of the equine hoof wall. Equine Veterinary Journal, Suppl. 26:46-50.
Noormohammady et al 2018. Effect of zinc on integrity of horse hoof. Agricultural & Veterinary Sciences Vol.2, No.1:17-23.
Hampson et al 2012. Effect of environmental conditions on degree of hoof wall hydration in horses. Am J Vet Res. 73(3):435-8.
Ott and Johnson (2001). Effect of trace mineral proteinates on growth and skeletal and hoof development in yearling horses. Journal of Equine Veterinary Science, Vol 21, No 6, 287-291.
