Current recommendations for the length of the dorsal hoof wall after trimming range from 60 to 85 mm; the most common recommendation being 75 mm. A British research study that examined internal claw structure using x-ray computed tomography (CT scan) suggests that the minimum external dorsal claw length recommendation should be increased to at least 90 mm for Holstein-Friesian cows over 4 years of age and at least 85 mm for younger cows.
There are 2 main causes of thin soles in dairy cattle:
1. an abrasive floor, particularly a new one in a barn cows have recently moved into;
2. excessive hoof trimming.
Without immediate intervention, some cows will completely lose the sole horn and the underlying corium, which is especially thin at the tip of the toe, will be uncovered. Therefore this area is very vulnerable for ascending infections. An alternative treatment for cattle with thin soles was presented at the recent Lameness Conference in Bristol UK.