The navicular bone is a tarsal bone located in the ankle joint between the talus and the cuneiform. This bone may be damaged in some cases. The commonest disease of this bone causes lameness in horses that mainly affects the forefeet. Having some knowledge of the foot anatomy is vital to understanding the management of navicular disease.
The exact cause of this condition remains unclear but there are a number of theories that have been forwarded. One of the commonest predisposing factors is the repetitive movement of the navicular bone and its support structures. For this reason, the incidence has been found to be higher in horses that are frequently take part in competitive races. Genetic factors and diet also contribute.
The resultant inflammation reduces blood flow to the ankle. The other effect is an increase in pressure in the heel. Pain sets in and horses start exhibiting lameness. The lameness is intermittent at first but becomes more constant with time. Horses start having a tip-toeing gait as they attempt to shift the pressure onto the anterior aspect. Stumbling will be seen every now and then.
It has been shown through research that there are a number of conformational defects that contribute to the problem. Most of these defects are those that make the feet more prone to concussion. Narrow and upright feet, long toes, small feet and upright pasterns are some of the examples. All these conformations increase the pressure that is exerted on the navicular bone. Shock absorption happens only to a certain extent beyond which the rest is transmitted to tissues causing damage.
If horses are trained on hard and irregular terrain, the risk is increased. This is because there is a tremendous amount of stress put on the main tendons predisposing them to wear and tear. This effect may also be seen in horses that spend a lot of time in the upright position. In this case, the cause is increased load transmission through the hoof. This is worsened by a high weight to foot ratio.
Poor shoe selection is another common cause of lameness. This problem is more common in domesticated then wild horses. It is for this reason that some experts have recommended barefoot trimming as opposed to the use of shoes. In the absence of shoes, they argue, feet can contract and expand freely allowing for blood to circulate freely.
Since the causes are numerous, it is not possible to come up with one form of treatment. For the diseases that are a result of degenerative changes, reversal of the damage is virtually impossible and the focus is mainly on symptomatic relief. The feet should be properly trimmed to achieve biomechanical and neurological balance. Another supportive measure is to reduce the work performed by the horse.
Pharmacotherapy has a role to play. Drugs are used for carefully selected cases. For instance, when blood flow is suspected to have been compromised, vasodilators are administered. They maintain patency of vessels and ensure blood is supplied to the affected areas. Other drugs that help with other aspects of this disease include NSAIDS, gallium nitrate, corticosteroids and bisphosphonates. Surgery is performed for cases that have failed to respond to other treatments.
The exact cause of this condition remains unclear but there are a number of theories that have been forwarded. One of the commonest predisposing factors is the repetitive movement of the navicular bone and its support structures. For this reason, the incidence has been found to be higher in horses that are frequently take part in competitive races. Genetic factors and diet also contribute.
The resultant inflammation reduces blood flow to the ankle. The other effect is an increase in pressure in the heel. Pain sets in and horses start exhibiting lameness. The lameness is intermittent at first but becomes more constant with time. Horses start having a tip-toeing gait as they attempt to shift the pressure onto the anterior aspect. Stumbling will be seen every now and then.
It has been shown through research that there are a number of conformational defects that contribute to the problem. Most of these defects are those that make the feet more prone to concussion. Narrow and upright feet, long toes, small feet and upright pasterns are some of the examples. All these conformations increase the pressure that is exerted on the navicular bone. Shock absorption happens only to a certain extent beyond which the rest is transmitted to tissues causing damage.
If horses are trained on hard and irregular terrain, the risk is increased. This is because there is a tremendous amount of stress put on the main tendons predisposing them to wear and tear. This effect may also be seen in horses that spend a lot of time in the upright position. In this case, the cause is increased load transmission through the hoof. This is worsened by a high weight to foot ratio.
Poor shoe selection is another common cause of lameness. This problem is more common in domesticated then wild horses. It is for this reason that some experts have recommended barefoot trimming as opposed to the use of shoes. In the absence of shoes, they argue, feet can contract and expand freely allowing for blood to circulate freely.
Since the causes are numerous, it is not possible to come up with one form of treatment. For the diseases that are a result of degenerative changes, reversal of the damage is virtually impossible and the focus is mainly on symptomatic relief. The feet should be properly trimmed to achieve biomechanical and neurological balance. Another supportive measure is to reduce the work performed by the horse.
Pharmacotherapy has a role to play. Drugs are used for carefully selected cases. For instance, when blood flow is suspected to have been compromised, vasodilators are administered. They maintain patency of vessels and ensure blood is supplied to the affected areas. Other drugs that help with other aspects of this disease include NSAIDS, gallium nitrate, corticosteroids and bisphosphonates. Surgery is performed for cases that have failed to respond to other treatments.
About the Author:
You can visit www.naviculardisease.com for more helpful information about The Management Of Navicular Disease Syndrome.
Aucun commentaire:
Enregistrer un commentaire