Keratex Nail Hole Damage Repair 200ml Open or damaged nail holes in hoof horn can be a potent source of infection. Squirting this powerful disinfectant into existing and/or old nail holes is an effective way of helping to prevent white line disease and infection. The formula also acts on the inside wall of the hole, hardening it so that the nail hole does not 'ladder' on the hoof, meaning that further splits and cracks can be prevented.