Hoof cracks are common in beef cattle, sometimes due to environmental factors or genetics because some cattle have stronger hoof horns than others.
Wet conditions can make hoofs soft and vulnerable to injury, and dry conditions can make the hoof wall more brittle and susceptible to cracking.
Dr. Michael Jelinski, a partner with Veterinary Agri-Health Services Ltd., in Airdrie, Alta., says dry conditions can contribute to lameness in beef cattle.
“Here in Western Canada we see a lot of what we refer to as sand cracks. Over the years there has been some good research regarding the causes, and a few theories that haven’t held up. The work that Dr. Chris Clark did (University of Saskatchewan) showed that the biggest risk factor is dryness of the hoof,” says Jelinski.
Clark says the cause of cracks is not always known.
“This question was the basis of my master’s project. We didn’t come up with complete answers, but we did discover that hydration, the water content, of hoof horn varies considerably throughout the year on the western Canadian Prairies.
“In summer, the moisture content of the hoof is fairly close to what I believe would be optimal. Even in dry years, the hoof tends to pick up some moisture. But as cattle go through winter here, the hoof dries out,” he says.
In a cold, dry climate, the feet are not exposed to any free water. There may be a lot of snow, but at cold temperatures the snow is dry and that moisture is not available. There’s no moisture in contact with the foot.
“Humidity is very low here in winter. We took hoof samples of cattle in February, when it’s typically -30 C. There is snow, but it’s very dry,” he says.
“As the hoof wall dries out, it becomes brittle. From studies done on horse hoofs, we know that as the hoof dries out, it becomes less pliable.”
Biomechanical studies on the feet of cattle with sand cracks (as well as moisture measurements) showed that the drier the foot, the higher the risk for cracks. The hoof wall becomes brittle, and more susceptible to cracking.
Jelinski says nutrition or genetics can be factors in hoof cracks, but are not the main causes.
As well, he says if dry conditions persist beyond winter as they have this spring there may be a higher incidence of cracks.
Cattle may also have to walk farther to water during a dry year, but as a general rule that won’t be a factor in hoof cracks, he says.
However, if cattle are travelling over rocky terrain or along a gravel road for long distances, it might lead to tender feet, stone bruising and possible lameness issues.
Most cracks appear on the outside front claw because it is a point of added strain and stress.
Cracks are common, but usually aren’t deep enough to cause lameness.
“Some of the survey data showed that up to 25 percent of a herd may be affected with sand cracks but only a small number actually become lame. When they do, it’s usually because of an abscess rather than from the crack itself,” Jelinski says.
In these instances, the crack could have been deep enough to get into the inner sensitive tissue of the foot, allowing bacteria access to those tissues and subsequent infection.
One thing Clark looked at was whether longer toes make the claws more vulnerable to cracking due to the added strain from the long toe.
“We found that the bigger feet were more prone to cracking, rather than the length of the toe, as the main factor. The volume of the foot was most important,” he says.
Many older beef cows on the Prairies are affected, but the vast majority of cracks don’t cause signs of lameness or ill health.
“My colleagues and I at the university looked at the feet of cattle that have gone to slaughter. The sand cracks almost never penetrate the entire thickness of the hoof wall. They are just in the outer layer. The way the hoof matrix is built, it has what is called a crack diversion mechanism. As the crack penetrates deeper, it is diverted away from going in a straight line.”
Pressure is dissipated outward rather than creating a deep split.
“The animal’s body responds to the crack by thickening the hoof wall in that area, to protect itself. Often the worst-looking cracks don’t cause lameness. If you cut into a dead hoof and look at it, you might discover that the hoof wall in that area may be up to two to three times thicker than normal.
“Sometimes, if the wall gets very thick in that area, you may also see a little remodelling of the bone, to accommodate the increased thickening of the hoof wall. Some of these cracks persist for years,” says Clark.
Treatment for lameness means resolving the abscess and getting rid of the infection.
“This involves opening up the crack using a very small grinder so the abscess can be drained and flushed,” Jelinski says.
Treatment is not as simple as an injection of antibiotics, as for a case of foot rot.
“If it is truly an abscess, it will require drainage before it can heal,” he says.
“You might want help from your veterinarian or a professional hoof trimmer, who deals with hoof health issues. They could pinpoint exactly where the abscess is, open it up and flush it.”
There is little producers can do to alleviate dry conditions for feet. The vitamin biotin, used in horses to promote healthy hoofs, can be of some help, but is not practical in a beef herd on extensive pastures.
“Hoof cracks are just something we tend to live with in Western Canada,” says Jelinski.
He says larger, heavier animals are likely to experience more cracks because they have more pressure and strain on the outside claws.
Clark says in commercial beef production, hoof cracks aren’t much of an issue. It’s not economically feasible to deal with them unless they cause lameness.
They might be a cause of concern in a purebred herd when the rancher is selling registered bulls and heifers.
“If someone comes to look at their animals, they don’t want cracked feet. Even in those cases, however, other than telling them they could try supplementing the cattle with biotin, I’m not sure what else to suggest to minimize cracks.
“They seem to be a prairie issue and are not reported as often in other parts of the world. It’s primarily an issue in Alberta, Saskatchewan and Manitoba.”