Navicular syndrome (caudal heel pain) is a diagnosis many horse owners dread. But this syndrome can be detected and treated. Today, our Mount Vernon vets will explain the causes, symptoms, and treatment of the navicular syndrome.
About Navicular Syndrome in Horses
Navicular disease is a group of related conditions affecting the navicular bone and associated structures in the foot. There are several possible causes of pain in and around the navicular bone.
The navicular bone is a small flattened bone, which lies across the back of the coffin joint. It attaches to the pedal bone via a short strong ligament (the impaired ligament) and the pastern joint by 'suspensory' ligaments. The deep digital flexor tendon runs over the lower surface of the navicular bone, which acts somewhat like a 'pulley', and between these lies a small pocket of fluid, the navicular bursa, that acts like a 'cushion' between the tendon and its 'pulley'.
There is no known cause for navicular syndrome currently. Damage to the navicular bone may occur due to interference with blood supply or trauma to the bone. Damage can occur to the deep flexor tendon, navicular bursa, or navicular ligaments all resulting in pain and lameness.
The navicular disease affects the front feet of horses causing a low-grade bilateral lameness, that usually progresses slowly. The lameness might only occur from time to time or when the horse is exercised on hard ground or in a small circle. In some cases, one foot is affected more than the other causing an obvious lameness. Affected horses may stand with the more painful foot in front placed on the other (pointing).
If you notice your horse acting differently please contact our Mount Vernon vets right away for emergency services.
The navicular syndrome can be treated but rarely cured. Corrective trimming and shoeing are important to ensure level footfall and foot balance. Often a rolled toe egg bar shoe is used to encourage early break over at the toe and good heel support. Medication such as phenylbutazone will elevate pain in many cases and enable work to be resumed. Long-term treatment with substances such as isoxsuprine and aspirin may improve blood supply to the navicular bone and improve the condition of the bone. Warfarin used to be a popular treatment. It 'thins' the blood and seems to help some horses although its use can predispose to excessive bleeding after a coincidental injury.
Long-term desensitization of the back of the foot can be achieved by performing a neurectomy to cut the heel nerves. This treatment should only be considered as a last resort and then only in full recognition of the implications. Postoperative complications are common and include rupture of the deep flexor tendon, painful inflammation of the cut nerve endings (neuromas), and damage to the foot that goes unnoticed by the horse and owner. Treatment options should be discussed in detail with your veterinarian.