In Part (1) I defined true navicular
disease (lameness due to bone change) is only apparent following a long series
of recurrent events. Applying “Physiological Sequencing” in defining this chain
of events, soft tissue is the first to undergo change in response to an
environmental alteration (balance change, increased vibration, friction and/or
pressure), followed by changes to the horn (dynamic tissue), before any
modifications to the bone become apparent on x-ray. The hoof capsule will show
deformity (flare, excessive wear or growth). As the horse reacts to pain, he
changes the way he loads the foot, and deformity appears. The deformity can be
minimal, but it will occur.
On rare occasions, a horse may show an acute-onset unilateral (affecting one limb) lameness, which leads to a diagnosis of navicular disease. It is my belief that short of a catastrophic insult (injury), pronounced unilateral lameness is more often the result of chronic loss of structure and chronic inadequate foot function.
How does conventional veterinary medicine approach treating this condition?
Conventionally, whether the diagnosis is disease or syndrome, most veterinarians will recommend corrective shoeing. Most commonly, this means an egg-bar shoe (said to give added support to the heel), accompanied by a rolled or rocker toe, wedge pads when needed to correct hoof pastern angle (HPA), and impression material for cushioning. But other shoeing protocols are used as well. Conventionally speaking, corrective shoeing, regardless of the shoe used, is dependent on the horse’s hoof-pastern angle. This approach to the problem is from the perspective of static mechanics, where pressure from the DDFT is the primary suspect for the cause of the disorder.
In addition, vets may recommend nonsteroidal anti-inflammatory medications to control foot pain, as well as phenylbutazone (bute), but not all horses with navicular pain respond to phenylbutazone. Medications to increase blood supply have also been prescribed. As a last resort, your vet may perform a surgical procedure known as a neurectomy. This procedure severs the nerve supplying the back of the foot but the results are often temporary.
How Does Applied Equine Podiatry Differ?
When presented with a horse diagnosed with navicular disease, it is imperative to evaluate the foot structure. As I do not subscribe to the conventional definition of a well-conformed foot, I assess the foot with an eye on the health of the Internal Arch Apparatus. Studies suggest that navicular pain results from a loss of those structures that help in maintaining proper bio-mechanical function of the joint, and in the positioning of the coffin bone in its relation to the joint and the distal limb. These structures include not only the distal sesamoidean ligaments and tendons, but also the ungular cartilages and digital cushion.
Where conventional thinking focuses on the stress exerted by the deep digital flexor tendon on the navicular bursa, and reacts to reduce this stress by reducing break-over or increasing foot angle, one should be more concerned with heel placement and the effect it has on the biomechanics of joint movement, circulation, and neurological function. Where are the heels in relationship to the center axis of the joint? No shoe can alter the position of heels in relationship to this center axis, but a shoe does alter the forces acting on the joint. This may temporarily reduce pain, but it is seldom successful in stopping the progression of the disease.
The conventional approach ignores the importance of the Internal Arch Apparatus and the role it plays in energy utilization and dissipation (Energetics). The key to treating navicular pain is to consider the whole. Simply trimming the heels to get them to the widest part of the frog, or reducing break-over, does not address the underlying cause of the pain – the loss of structure causing undue stress on the supporting structures of the joint.
Instead providing correct stimulus will ultimately result in reducing the stresses associated with the progression of the disease process helping to restore sound structure and proper function. Pain management is essential during this time. Pain can effectively be managed with the help of the veterinarian, and by the use of several appliances (pads, boots, hoof wraps, specialty shoes) that support correct foot function. .
Over the past two decades, I have worked on many horses diagnosed with navicular syndrome/disease, and most had weak structure to the caudal (back) aspect of the foot. But with correct trimming to achieve balance of the hoof capsule to that of the Internal Arch Apparatus, the appropriate application of stimulus (exercise/pressure) to aid in the return of correct structure, and sound pain management practices many horses returned to work. Review Part One (1)
On rare occasions, a horse may show an acute-onset unilateral (affecting one limb) lameness, which leads to a diagnosis of navicular disease. It is my belief that short of a catastrophic insult (injury), pronounced unilateral lameness is more often the result of chronic loss of structure and chronic inadequate foot function.
How does conventional veterinary medicine approach treating this condition?
Conventionally, whether the diagnosis is disease or syndrome, most veterinarians will recommend corrective shoeing. Most commonly, this means an egg-bar shoe (said to give added support to the heel), accompanied by a rolled or rocker toe, wedge pads when needed to correct hoof pastern angle (HPA), and impression material for cushioning. But other shoeing protocols are used as well. Conventionally speaking, corrective shoeing, regardless of the shoe used, is dependent on the horse’s hoof-pastern angle. This approach to the problem is from the perspective of static mechanics, where pressure from the DDFT is the primary suspect for the cause of the disorder.
In addition, vets may recommend nonsteroidal anti-inflammatory medications to control foot pain, as well as phenylbutazone (bute), but not all horses with navicular pain respond to phenylbutazone. Medications to increase blood supply have also been prescribed. As a last resort, your vet may perform a surgical procedure known as a neurectomy. This procedure severs the nerve supplying the back of the foot but the results are often temporary.
How Does Applied Equine Podiatry Differ?
When presented with a horse diagnosed with navicular disease, it is imperative to evaluate the foot structure. As I do not subscribe to the conventional definition of a well-conformed foot, I assess the foot with an eye on the health of the Internal Arch Apparatus. Studies suggest that navicular pain results from a loss of those structures that help in maintaining proper bio-mechanical function of the joint, and in the positioning of the coffin bone in its relation to the joint and the distal limb. These structures include not only the distal sesamoidean ligaments and tendons, but also the ungular cartilages and digital cushion.
Where conventional thinking focuses on the stress exerted by the deep digital flexor tendon on the navicular bursa, and reacts to reduce this stress by reducing break-over or increasing foot angle, one should be more concerned with heel placement and the effect it has on the biomechanics of joint movement, circulation, and neurological function. Where are the heels in relationship to the center axis of the joint? No shoe can alter the position of heels in relationship to this center axis, but a shoe does alter the forces acting on the joint. This may temporarily reduce pain, but it is seldom successful in stopping the progression of the disease.
The conventional approach ignores the importance of the Internal Arch Apparatus and the role it plays in energy utilization and dissipation (Energetics). The key to treating navicular pain is to consider the whole. Simply trimming the heels to get them to the widest part of the frog, or reducing break-over, does not address the underlying cause of the pain – the loss of structure causing undue stress on the supporting structures of the joint.
Instead providing correct stimulus will ultimately result in reducing the stresses associated with the progression of the disease process helping to restore sound structure and proper function. Pain management is essential during this time. Pain can effectively be managed with the help of the veterinarian, and by the use of several appliances (pads, boots, hoof wraps, specialty shoes) that support correct foot function. .
Over the past two decades, I have worked on many horses diagnosed with navicular syndrome/disease, and most had weak structure to the caudal (back) aspect of the foot. But with correct trimming to achieve balance of the hoof capsule to that of the Internal Arch Apparatus, the appropriate application of stimulus (exercise/pressure) to aid in the return of correct structure, and sound pain management practices many horses returned to work. Review Part One (1)
1. Pool RR, Meagher DM, Stover SM,
Pathophysiology of navicular disease, Vet Clin North Am Equine Pract 1989; 5:
109-129
2. Ross MW, Dyson SJ, Lameness in the Horse, Philadelphia, 2003 Saunders
3. Leach DH, Treatment and pathogenesis of navicular disease in horses, Equine Vet J 1993; 57: 415-421
4. Thompson KN, Rooney JR, et al, Considerations on the pathogenesis of navicular disease, J Equine Vet Sci 1991; 11: 4-8
5. La Pierre, KC, The Chosen Road, Achieving High Performance Through Applied Equine Podiatry, Dover, Naked Greyhound Press, 2003
2. Ross MW, Dyson SJ, Lameness in the Horse, Philadelphia, 2003 Saunders
3. Leach DH, Treatment and pathogenesis of navicular disease in horses, Equine Vet J 1993; 57: 415-421
4. Thompson KN, Rooney JR, et al, Considerations on the pathogenesis of navicular disease, J Equine Vet Sci 1991; 11: 4-8
5. La Pierre, KC, The Chosen Road, Achieving High Performance Through Applied Equine Podiatry, Dover, Naked Greyhound Press, 2003
No comments:
Post a Comment