Understanding equine health is crucial for any horse owner or enthusiast. One condition that can significantly impact a horse’s performance and well-being is navicular disease. This debilitating ailment affects the navicular bone and surrounding structures in the horse’s foot, leading to pain, lameness, and potential career-ending consequences.
What Is Navicular Disease in Horses?
Navicular disease is a complex and often chronic condition that primarily affects the navicular bone, a small bone located in the back part of the horse’s hoof. It involves inflammation and degeneration of the navicular bone, the navicular bursa (a fluid-filled sac that cushions the bone), and the deep digital flexor tendon which runs along the back of the leg and attaches to the navicular bone.
Causes and Risk Factors
The exact cause of navicular disease is not fully understood, but it is thought to be a combination of genetic predisposition, biomechanical factors, and environmental influences.
- Genetic predisposition: Certain breeds, such as Thoroughbreds, Arabians, and Quarter Horses, are more susceptible to navicular disease.
- Biomechanical factors: Incorrect hoof conformation, such as narrow heels or long toes, can put excessive stress on the navicular bone and surrounding structures.
- Environmental influences: Hard, unforgiving surfaces, excessive concussion, and prolonged periods of standing can contribute to the development of navicular disease.
Symptoms and Diagnosis
Early signs of navicular disease can be subtle and may include lameness that is worse after exercise, heat or swelling in the hoof, and a reluctance to move. As the condition progresses, lameness may become more severe, and the horse may exhibit a characteristic “toe-first” gait.
Diagnosis involves a thorough physical examination, including palpation of the hoof and observation of the horse’s gait. Imaging techniques, such as X-rays, ultrasound, and MRI, can help to confirm the diagnosis and assess the severity of the disease.
What is Navicular Disease in Horses?
Navicular disease is a debilitating and complex condition that affects the navicular bone, the small bone located in the back of the horse’s hoof. This condition is characterized by inflammation and degeneration of the navicular bone, the navicular bursa (a fluid-filled sac that cushions the navicular bone), and the surrounding soft tissues, including the deep digital flexor tendon. Navicular disease is a common cause of lameness in horses, particularly in middle-aged and older horses, and can significantly impact a horse’s performance and quality of life.
Causes of Navicular Disease
The exact cause of navicular disease is unknown, but it is thought to be a combination of genetic predisposition, biomechanical factors, and environmental influences. Some contributing factors include: (See Also: What Horses Like To Eat)
- Genetics: Certain breeds, such as Thoroughbreds, Quarter Horses, and Arabians, are more susceptible to navicular disease.
- Conformation: Horses with certain conformational traits, such as long, sloping pasterns or low heels, may be more prone to developing navicular disease.
- Excessive Workload: Overuse or repetitive stress on the navicular bone, particularly on hard surfaces, can contribute to the development of the disease.
- Poor Farriery: Improper shoeing practices, such as using shoes that are too short or too long, can increase stress on the navicular bone.
- Nutrition: Deficiencies in certain nutrients, such as calcium and phosphorus, may contribute to the development of navicular disease.
Symptoms of Navicular Disease
The symptoms of navicular disease can vary depending on the severity of the condition. Some common signs include:
- Lameness: This is the most common symptom of navicular disease, and it is often worse after exercise or when the horse is standing on hard surfaces.
- Heat and Swelling: The area around the navicular bone may be warm to the touch and swollen.
- Digital Pulses: The digital pulses, which are located on the back of the horse’s leg, may be weak or absent.
- Short Strides: Horses with navicular disease may shorten their stride length to avoid pain.
- Difficulty Picking Up the Feet: The horse may be reluctant to lift its affected foot.
Diagnosis of Navicular Disease
Diagnosing navicular disease can be challenging, as the symptoms can be similar to other hoof conditions. Veterinarians use a combination of clinical examination, radiographs (X-rays), and other diagnostic tests to confirm the diagnosis. Some diagnostic tools include:
- Physical Examination: The veterinarian will examine the horse’s hooves, legs, and gait to assess for any signs of lameness or pain.
- Radiographs: X-rays can reveal changes in the navicular bone, such as fragmentation, sclerosis (hardening), or bone cysts. They can also show changes in the surrounding soft tissues.
- Ultrasound: Ultrasound imaging can be used to evaluate the navicular bursa and the deep digital flexor tendon for inflammation or degeneration.
- Nuclear Scintigraphy (Bone Scan):** A bone scan can help identify areas of increased bone activity, which may indicate inflammation or damage to the navicular bone.
Treatment of Navicular Disease
There is no cure for navicular disease, but there are a number of treatment options that can help manage the symptoms and improve the horse’s quality of life. Treatment plans are individualized based on the severity of the disease and the horse’s overall health. Some common treatment options include:
- Rest and Turnout: Allowing the horse to rest and move freely in a paddock can help reduce stress on the navicular bone.
- Controlled Exercise: A veterinarian may recommend a specific exercise program that is tailored to the horse’s condition. This may involve walking, swimming, or other low-impact activities.
- Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) can help reduce pain and inflammation. Other medications, such as corticosteroids, may be used in some cases.
- Shoeing Modifications: A farrier can make adjustments to the horse’s shoes to reduce stress on the navicular bone. This may include using egg-bar shoes, heart-bar shoes, or other specialized shoes.
- Extracorporeal Shock Wave Therapy (ESWT):** ESWT uses sound waves to stimulate healing in the navicular bone and surrounding tissues.
- Platelet-Rich Plasma (PRP) Therapy: PRP therapy involves injecting the horse’s own platelet-rich plasma into the affected area to promote healing.
- Stem Cell Therapy:** Stem cell therapy is a relatively new treatment option that involves injecting stem cells into the affected area to stimulate tissue regeneration.
Prognosis for Horses with Navicular Disease
The prognosis for horses with navicular disease varies depending on the severity of the condition, the age of the horse, and the response to treatment. Some horses may experience significant improvement with conservative management, while others may require more aggressive treatment options. Early diagnosis and intervention are essential for improving the long-term outcome for horses with navicular disease.
Prevention of Navicular Disease
While there is no guaranteed way to prevent navicular disease, there are some steps that horse owners can take to reduce the risk of their horses developing the condition:
- Regular Veterinary Checkups: Have your horse’s hooves and legs examined by a veterinarian regularly to identify any potential problems early on.
- Proper Farriery: Work with a qualified farrier to ensure that your horse’s shoes are properly fitted and maintained.
- Balanced Diet: Provide your horse with a balanced diet that is rich in calcium, phosphorus, and other essential nutrients.
- Appropriate Exercise:** Avoid overworking your horse, especially on hard surfaces. Provide your horse with plenty of turnout time and allow for adequate rest.
- Conformation Evaluation: If you are breeding horses, consider having their conformation evaluated by a veterinarian or equine specialist to identify any potential predispositions to navicular disease.
Recap
Navicular disease is a complex and debilitating condition that affects the navicular bone and surrounding tissues in the horse’s hoof. While the exact cause is unknown, it is thought to be a combination of genetic predisposition, biomechanical factors, and environmental influences. Symptoms include lameness, heat and swelling, and difficulty picking up the feet. Diagnosis involves a combination of clinical examination, radiographs, and other diagnostic tests. Treatment options range from rest and controlled exercise to medications, shoeing modifications, and advanced therapies such as ESWT and stem cell therapy. Early diagnosis and intervention are crucial for improving the long-term outcome for horses with navicular disease.
By understanding the causes, symptoms, and treatment options for navicular disease, horse owners can take proactive steps to manage the condition and improve the well-being of their equine companions.