The physical break in the toe nail or dewclaw causes a cracked nail with an exposed nail bed. The nail bed can bleed or become infected. This can be so painful that your pet may stop bearing weight on the affected leg. If left untreated, nail infections can spread up to the joints of the toe and can lead to irreparable damage such that the toe itself has to be amputated.
Following nail bed damage, the nail may or may not grow back at all or can grow back abnormally.
Treatment
Treatment is focused on removing the broken nail back to the nail bed. This is generally done under sedation or general anaesthesia due to pain and sensitivity of the exposed nail. The hair around the nail is clipped away and the skin is disinfected. The remaining nail is removed and a bandage is used for protection for 2-3 days which needs to be removed at home.
Most cases will require antibiotics and pain relief. A tetanus antitoxin injection may also be given.
Rechecking of the nail bed is extremely important. If lameness persists it is still possible that amputation of the toe may be required.