Some horse diseases can cause severe lameness in horses.
Naviculs Syndrome is a degeneration of the navicular bone (NB), usually in the front feet of the horse. It can lead to severe lameness. But with today’s advances in veterinary medicine and shoeing, this does not have to be the case.
This is Black Jack. He is a 16 year old grade, 14-2 hand, black Morgan Pony. He has been with us for 11 years. He has never been lame a day of his very active life. During a pre-purchase exam (6 years ago) he was diagnosed by a veterinarian as having navicular syndrome (NS). This diagnosis came after sensitivity shown to the hoof testers and radiographs showing changes to the navicular bone.
So why isn’t he lame?
It is important to stress that for this disease to exist 3 elements have to be present at the same time.
- Radiographic changes
- Sensitivity to the hoof testers.
Black Jack has continued his eventing career and has taught a multitude of children how to ride. We are very careful with his shoeing, nutrition and work schedule. Radiographic changes have not progressed from 6 years ago.
The navicular bone is located behind the coffin bone and under the small pastern bone. The deep digital tendon flexor (DDF) attaches to the back of the coffin bone after running on top of the navicular bone. Cartilage lies between the coffin bone, NB and DDF.
Things that are thought to cause Navicular Syndrome…
The cartilage degenerates probably caused by too much compression between the coffin bone and the navicular bone. The ligaments that support the navicular bone are constantly put under too much tension , this can begin the process of degeneration.The DDF tendon is placed under excessive strain for long periods of time, perhaps due to poor shoeing, this can begin the process of bone changes and tendon inflammation.Some horse-diseases are congenital.
Things that are thought to contribute to Navicular Syndrome…
Defects in the conformation of the foot of the horse can cause more compression and stress to the navicular and coffin bone as well as the tendons and ligaments. Some of these conformational defects are inherited but even more can be caused by poor shoeing.The type of work that the horse does can also place excessive stress on the DDF. An example of this type of work would be jumpers, and cutting horses. Work that causes excessive concussion to the hoof such as working on hard or irregular ground can also be a contributing factorBeing confined for long periods of time without the ability to move around also may apply constant pressure to the NB.Early detection of horse-diseases is the best way to reverse the detrimental affects on the horse.
- Intermittent lameness
- Slight heel pain displayed by the horse stepping more toe to heel.
- Radiographic changes
- Sensitivity to hoof testers