Navicular syndrome or navicular disease is the cause for one-third of all chronic front-end lameness in horses. This condition can be difficult to diagnose and typically involves the navicular bone, navicular bursa, deep digital flexor tendon and other soft tissue structures that make up the navicular apparatus. Research has demonstrated that while many treatment options are available only 65% to 75% of affected horses will see an improvement in performance and approximately 50% of those that experience an improvement will be able to maintain that condition for one to two years, making long term success variable and increasing owner frustration.
A horse with navicular syndrome will commonly experience heel pain and will shift their weight to their toe while moving. This creates a shortened, choppy stride. They will also commonly display a pain response when hoof testers are applied over the middle third of the frog. The degree of lameness varies based on the severity of the progression and pain tolerance of each individual. Navicular syndrome is a complex and multifactorial condition. The exact cause remains unclear, but there are several factors that may contribute to the disease.
Treating navicular syndrome is often challenging due to its chronic nature and the involvement of multiple structures within the hoof. However, several approaches can manage symptoms and potentially slow disease progression:
The progression of the disease varies; some horses may manage with mild symptoms for many years, while others might experience a rapid decline in hoof function. Early diagnosis and proper management are crucial in extending a horse's performance career. With appropriate treatment and care, some horses can continue to perform at a competitive level, though they may require modifications to their workload and shoeing regimen. Unfortunately, the chronic nature of navicular syndrome often leads to a gradual decline in a horse's ability to perform. As the condition progresses, affected horses may need to be retired from high-impact activities. Their roles may shift to less demanding tasks, or they may transition into a breeding or companion animal role. Horse owners and veterinarians must work closely to tailor a management plan that addresses the individual needs of each horse, with the ultimate goal of maintaining their quality of life and extending their useful careers.
A navicular x-ray. Photo by Meredith Hicks