Veterinary science has learned a lot about the once seemingly mysterious navicular in horses. Decades ago, it was called navicular disease and still is called that in older horse books. Nowadays, science has discovered that navicular in horses is a syndrome and not a disease.
The bad news is that navicular is a serious and incurable condition that can happen to horses of all breeds. Older horses are especially susceptible since their legs and hooves have taken a lot of pounding over the years. The good news is that navicular is preventable and treatable.
What Is Navicular in Horses?
The navicular bone is a tiny boat-shaped bone in the horse’s hoof. It helps keep the whole foot and leg moving smoothly. When this little bone and surrounding tissues have problems, the horse becomes lame. Common symptoms of navicular in horses and ponies include:
- The horse seems to be walking on tip-toe to take pressure off the heel where the pain is located. This can cause stumbling. The horse gaits will change making him or her more uncomfortable to ride.
- The horse becomes mildly lame some of the time. As navicular progresses, the lameness will become worse and more constant.
- The horse shifts from one leg to another more often than usual.
- The horse’s shoes wear down unevenly. The toes are usually worn out faster than the heels.
If left untreated, the hooves will eventually change shape and curve upwards like horns. Even corrective trimming and shoeing will not make the hoof grow back normally. The horse will become permanently lame.
What Causes Navicular in Horses?
The main causes of navicular in horses and ponies include:
- Genetic problems or birth defects.
- Overwork which causes too much stress on the hooves. Racehorses are especially prone since they are asked for demanding work when they are as young as two. A horse’s skeleton does not stop growing until the horse is five.
- Poor shoeing practices, such as forcing a hoof to fit a shoe instead of patiently selecting a shoe that fits the hoof.
- Hooves that have been neglected for so long that they become grotesquely long or deformed.
- Being overweight which puts unnecessary strain on the hooves.
- Accidents to the navicular or hoof. Even when healed, these injured areas will never be as strong as before the accident.
- A combination of the above causes.
Just how these factors cause the navicular bone and surrounding tissues to become inflamed and painful is unknown. Navicular is more common in the forelegs. Just why is also unknown.
Treatment Options Available for Navicular in Horses
There are many treatment options for horses with navicular. Usually a horse needs a combination of treatments in order to get relief and improve. Horses with navicular need management changes, drugs, corrective shoeing and possibly surgery.
Management changes include:
- Putting the horse on a diet if he or she is overweight.
- Changing the horse’s stall flooring to make it softer.
- Letting the horse have longer rest periods after working.
Corrective shoeing with a skilled farrier helps make sure the horse is placing even weight on all four legs. Special shoes like egg-bar shoes helps takes the pressure off the heel and navicular bone. Wedges or small cushions in between the shoe and the hoof also help as shock absorbers.
Painkillers help reduce not only pain but swelling. These painkillers include:
- Phenelbutazolen (bute);
- Non-steroidal anti-inflammatory painkillers (NSAIDS.)
Many of these drugs are banned for horses competing in certain sports. A horse may also be treated with a vaso-dilator to help improve blood circulation to the navicular area.
Surgery for navicular in horses is called a digital neurectomy or nerving. This is a controversial treatment since it can lead to a devastating breakdown. Surgeries cut the nerves around the painful area so the horse does not feel pain. Unfortunately, horses that cannot feel pain will run or work on severely damaged hooves. This leads to fractures or legs breaking. A horse in pain will not work himself to death. A horse that has been nerved needs light work for the rest of his or her life. Many horse sports will not allow nerved horses to compete.
Alternative treatments include:
- Regular massage;
- Extracorporeal shock wave therapy.
However, these treatments are nowhere as reliable as conventional treatments.
Prevention of Navicular in Horses
Navicular is caused by overwork and poor shoeing and standing or working for long periods on hard surfaces. Therefore, commonsense horse management practices can help prevent a horse or pony from suffering with it. Following these tips not only will help prevent navicular in horses and ponies but also many other health problems and causes of lameness:
- Do not overwork horses. Young horses with skeletons still developing need slow and gradual build-up to hard work like jumping or racing. If a horse is sweating profusely and breathing like a bellows, he is giving his all.
- Check hooves and legs before and after exercise or work. The sooner an injury is spotted, the better it can be treated and creates less of a strain on the navicular bone.
- Stable flooring should be soft but firm and dry. Do not just place a layer of straw or sawdust over cement.
- Keep the horse from getting too fat.
- Shoe or trim the horse’s hooves about every six weeks.
- Horses that seem overworked or going lame need their legs iced and need rest.
- Never breed horses with poor confirmation. This is because they are more prone to developing navicular than horses with good confirmation.
Just a few decades ago, a diagnosis of navicular was one of the most dreaded a horse could have. Although navicular does not kill a horse, it often forced a sudden retirement. Retired horses that cannot work tend to be sold for slaughter.
These days, the prognosis for a horse with navicular is much brighter. Many horses diagnosed with it will still have to retire from strenuous competitions like racing or Grand Prix show jumping. However, they often can still do light work for many years to come.
The images are from pixabay.com.