This horse's death and alot of pain and expense could have been avoided.
Knowing the early signs to watch to watch for could have saved this horse!
Navicular Syndrome causes gradual and progressive lameness of the front legs over years.
Due slow onset of the condition, it usually progresses undiagnosed until it's very serious.

Stage 1 - Asked to stand still for a few minutes when mounted the horse may "dance" or do "tail-swishing" or do "head-bobbing" and may be lame after work. It would, if tested after work indicate pain response in navicular area, but the lameness will typically disappear with rest, and so it will usually go undiagnosed.
Stage 2 - The horse will shorten its stride to cause breakover to happen earlier, reducing pain. The horse may begin pointing while at rest, with one leg extended approximately 6 to 12 inches in front of the other to reduce pressure from the DDF tendon against the navicular area. Unweighting causes reduced bloodflow and the foot will begin to contract somewhat and become dry. To change the angle of the foot to relieve pressure, the horse may stand with feet resting up on door sills, fencing, ant hills or with feet in holes in the ground.
Stage 3 - The horse may continually "weave" while standing at rest, shifting weight from one foot to the other to relieve pain, but this may be attributed to stress or some other cause. The DDF tendon and/or the navicular bursa become crushed and cause severe pain. Chronic inflammation will begin to cause physical damage to the inner hoof. With chronic pain the horse will undergo a mood change and be generally irritable.
Stage 4 - Bursa is permanently damaged. Bloodflow to frog stops. Hoof fails to expel metabolic waste and Liver and Kidneys are damaged. Horse spends much time lying down, causing general circulation problems. Note that the horse below has become lethargic due poor nutrition and depression ( the horse with his nose to the ground is telling you he is depressed. ) Note the scars from other horses and a pitch-fork. The horse afflicted with Stage 4 Navicular Syndrome does not want to move, preferring to lie with its feet under it to relieve the pressure from the DDF tendon against the Navicular area. This 28 year old Stallion almost went for meat.


In the horse, the Navicular bone is located directly behind the coffin bone and is held in place by tendons and ligaments. The Navicular bone's functions are to protect the joint and tendons from pressure and concussion, acting like a pulley on the deep digital flexor tendon, taking some of the stress off the coffin bone. This is the area of the pain in Naviculare Syndrome. The Navicular Bone also acts as a valve for blood flow to the coffin bone and hoof corium. The latter is a life-sustaining function, as this blood flow works to rid the horse's body of metabolic waste products.

In other words, toxins in the horse's body are expelled into new hoof growth and eventually exit the body this way. This is why your horse gets laminitis or "founders" when it drinks too much water, eats too much green grass, begins new feed type or various other things. The horse is designed to get as much nutrients from the available food as it can. When accustomed to getting food with low nutritional value ( old hay & grain or dry grass ) its body works hard to extract the maximum amount of nutirents. When high-nutrient food is suddenly introduced to the horse whose body had adapted to obtain maximum nutrition for the lower quality feed, it's like putting rocket fuel in a car, it burns too hot & damages the engine.

The change causes metabolic waste (toxins) to go into the hoof first, but there is often too much toxin to handle all at once. If the hoof's waste-removal system is not functioning well, generally your horse will not only suffer from hoof pain but also the liver and kidneys will be damaged over time because the toxins from minor changes in feed quality will not be absorbed by the hoof and will end-up in the liver or kidneys and will lead to the eventual failure of these organs. This alone can cause the horse to be unhealthy in later-years and take years off of its life expectancy. Alternatively, the pain of Navicular Syndrome is progressive and will eventually be significant enough to cause the horse to be unable to stand and the laying horse's own weight will cause circulation problems. Left untreated, Navicular Syndrome will cause death.

Many unfortunately believe that the afflicted horse does not wish to step on his heel and that is why he will shorten his stride. However, the horse is actually trying to reduce tension/pressure from the deep flexor tendon on the Navicular area. The highest pressure/tension ( causing the most pain ) is just before the hoof “breaks over”. Hence, the further under the horse the hoof is in full contact with the ground, the more it hurts. The horse is trying to pick-up the supportive limb as soon as possible to bring the opposite leg that is in the air to the ground as soon as he can. That is the reason for shorter stride when afflicted by navicular injury and it is NOT that he doesn’t want to put weight his heel, as commonly believed.

It is only in the more advanced stage, that the horse can feel the pain in his heel at all times due to the soft bone-tissue growth which will then reduce even more the blood supply to the foot (by that time he will be also sore in many other parts of his body as the secondary effects begin). If the horse would be preventing the stepping on his heel, thus preventing the stress on it, the lifting of the heel like the use of wedge pads would make things worse, especially when it comes to landing and impact since the heels would land first. The majority of Vets and farriers will try but fail to resolve Navicular Syndrome with treatments that did not work 100 years ago. You will still pay them for their time, regardless. So, let them diagnose it. Let me fix it.