White line disease (WLD) is not a disease as such, but a result of damage to the hoof, allowing in infection.

Any break in the integrity of the sole or wall lets in dirt and bacteria. The bacteria multiply, forming an abscess, undermining and loosening the sole and allowing in more grit and small stones, causing considerable pain.

Lameness is often blamed on farm roadways and, no doubt, uneven potholed and wet surfaces with loose stones contribute to the problem.

Insufficient, badly designed, or small cubicles, where cows cannot lie down easily, quickly and comfortably, result in them spending a lot of time standing, is another major cause.

There should be at least one cubicle per cow.

Cows should be lying down 12 to 14 hours per day at least. If they spend a long time standing, it causes lengthening of the flexor tendons, which interferes with circulation to the hoof, resulting in deformity where parts of the hoof overgrow due to lack of wear.

Looking at a lot of lameness in cows over many years, I am of the opinion that the scraper system with horizontal bars, especially with cogs sticking up, are a contributory factor to this problem.

Cows standing on those cogs with their full weight will definitely damage the sole of the foot.

Their feet also slip off the bars, with a loud cracking noise, even sending dirt as far as the roof.

Contusion caused by that slippage causes internal bleeding, like when you hit your fingernail with a hammer. This bleeding will separate the internal lamina joining the sole and wall of the hoof to the pedal bone, making it vulnerable to penetration by stones later on.

Toe necrosis, an extremely painful and almost untreatable condition, could be caused by these contusions.

Sometimes, cows backing off cubicles inadvertently stand on these bars and, if bunched or rushed while moving in cubicle houses, will not have a choice as to where to put any foot, especially the back ones.

In some feeding passages, the scraper bar is at the exact spot almost where the hind feet are placed.

I think the nylon rope system, rather than the bar, would certainly make a major contribution inreducing white line disease on farms.

Jim Kelleher MVB MRCVS CertDHH works at Riverview Veterinary Group, Bandon, Co Cork. Riverview Veterinary Group is part of XLVets. XLVets is a group of progressive practices who are working together to achieve a better future for agriculture and veterinary in Ireland. For information, see www.xlvets.ie.