In the first three articles in this hoof care series, I discussed the role that management and the environment plays in claw problems, as well as genetic disorders and how it can be identified. In the next two articles the focus shifts to the most common reason for lameness in cattle, namely fissures in claws.
There are two types of fissures, namely horizontal (discussed in this article) and vertical. Both types cause severe lameness and have their own risk factors and causes. Fissures appear in cows and bulls, although more cases of lameness are reported in bulls – this can be attributed to the difference in weight between male and female animals.
The physiology of a fissure
Horizontal fissures are found in dairy cows and beef cattle and can be described as a fissure that is visible on all four feet and all eight claws. The horizontal fissures on the claws will be at the same height, thus the same distance from the hairline. Another characteristic of such a fissure is that separation of the hoof wall is visible all around the claw, from the heel to the interdigital area.
While the fissure is still high up on the claws, it normally does not cause too much lameness. As the claws grow out, however, the fissure moves closer to the bottom. When it reaches 75% of the total length of the claw (approximately 56mm) it becomes more painful. This is because the forces on the toes, where the break-over occurs while walking, cause the claw to break at the point of the fissure.
If the feet are overgrown and not in good shape, the leverage forces on the toe increase. A claw that cracks into the live tissue causes severe pain in all the claws simultaneously. In extreme cases such as this, applying a block to relieve the pressure will mostly be of little help.
Only an experienced hoof trimmer who uses the correct equipment can take care of such a problem, as the procedure requires a very specific technique. Afterwards, the livestock owner must keep such an animal in an enclosed area with a soft surface where it can get enough rest. This will promote regrowth and full recovery of the lesion.
Why do horizontal fissures occur?
Horizontal fissures are also known as ‘stress rings’ or ‘hardship grooves’. These fissures are often seen in cows experiencing calving difficulties, or in animals presenting with a high fever or intense stress for a prolonged period, among other things. This causes an interruption in keratin production. When keratin production resumes, it causes a weak spot in the claw. – Jaco de Bruin, Dairysmid