What is Navicular Syndrome in Horses?
Sometimes we tell people, or our critters, that they are a pain in the you-know-what. But today I want to talk about the 'pain-in-the-heels' horses. Or, horses that have heel pain.
Illustration from Horse Science Images Vol. I and Navicular: The Theories, Opinions and Attitudes by PENZANCE NHC101 Student Barbara Money, Feb. 2009.
More commonly known as Navicular syndrome.
In former articles, I've discussed and distinguished the difference between Navicular DISEASE and Navicular SYNDROME. Navicular DISEASE is not all that common and is a degenerative DISEASE of the Navicular Bone. It can only be accurately diagnosed through a series of radiographs spanning two to three years. Navicular SYNDROME is very common and merely says the horse has discomfort in the caudal area of the hooves.
It has become a 'catch-all' term when veterinarians cannot definitely diagnose a specific 'disease' that would explain why a horse is lame.
I'm not saying that in judgement by any means. I'm merely stating that as a fact.
Photo courtesy of Oklahoma State University
"Conventional veterinary medicine defines navicular disease as a single disease. Given the variety of symptoms that manifest in lameness of the fore foot, however, it is likely that several different conditions, with different origins, are responsible for pain associated with the navicular region. MRI evidence confirms that many other problems in horses cause the same clinical signs as those in horses diagnosed with navicular disease. This has lead some researchers to question the term "navicular disease", feeling that it no longer applies to many of the horses being evaluated for foot lameness problems. Heel Pain Besides navicular disease, there are many things that can cause pain in the horse's heel region. Here's a look at where things can go wrong:
- Strained distal sesamoidean impar ligament
- Changes of the collateral ligaments (visible with MRI) of the navicular bone
- Mismatched feet (usually one foot has a long toe/low heel, while the other foot is more upright)
- Deep digital flexor tendon lesions
- Adhesions between the deep digital flexor tendon and the distal sesamoid bone
- Fibrocartilage on the bottom of the navicular bone "
-- Nancy Camp, Navicular Disease: The Theories, Opinions and Attitudes, PENZANCE NHC101 Student 4/7/09
The majority of performance horses, especially in the US, are clad with shoes and never have a chance to go barefoot. This results in many discomforts, the least of which is contracted and under-run heels with weight-bearing bars. Medications are prescribed, orthotics are encouraged, the hooves are trimmed to the shoes frequently (in contrast to the shoes being properly fitted to properly trimmed hooves) and, eventually, within a couple of years of this type of "care" the horses are so lame that the nerve is cut surgically.
"But did you know that the nerves in that heel area can grow and eventually allow the horse again to feel pain? This innervation or regrowing of the nerves is the norm rather than the exception with a neurectomy. According to equine surgeon John Madison, VMD, Diplomate ACVS, a neurectomy always should be considered a temporary procedure." --Barrie Grant, DVM, Dipl. ACVS | Oct 1, 1997
Side effects of a neurectomy includes stumbling and ruptured deep flexor tendons. Cutting nerves is never the answer.
Seeing that the horse has adequate hoof care, husbandry, diet and exercise and a hoof care provider who is skilled and knowledgeable in rehabbing "Navicular Syndrome" in horses, is the answer.
I am not about to try to explain 'How to Trim a Navicular Horse' as each hoof, is so individualistic that to try to explain would really just be misinformation. The 'Hoof-in-hand' on the 'Horse-in-hand' MUST be trimmed correctly according to the individual hooves 'needs'.
A good, correct trim is always an appropriate place to start. In my own experience with rehabbing navicular horses, comfort from a correct trim is evident directly after the trim session. If there is still discomfort, then I found that within 4 months of correct trimming and care, the horse all of a sudden comes 100% sound.
It's pretty amazing what miracles can take place when hooves are correctly trimmed. On the contrary, it's deeply disturbing to see so many horses with incorrect trims, and hearing horse owners' stories of the diagnosis from their professionals with the only answer of euthanasia! That is far too common!
Equine hooves are a marvel of engineering design - creation. When given the correct parameters, horses will gallop untold miles per day over rocks, through water, sand and even on mountainous terrain ... and lo and behold they aren't sportin' shoes!
The next time your horse is ouchy and you fear navicular, mention something to your hoof care provider and take a good, hard look at how your horse's hooves are trimmed, how they wear, what the horn quality consists of and how much heel your horse has. Too many trim methods are dangerously advising for heels to be almost completely cut down for a 'ground parallel' coffin bone. This can lead to negative palmar angles which eventually can lead to under-run heels and forward-growing hooves - the pinnacle for Navicular syndrome.
Don't let your horse be a Pain in the ... Heels.
Gwenyth Browning Jones Santagate is the world-renowned author of "10 Secrets to Healthy Hooves" and "Natural Hoof Anthology" as well as a noted author for various international equine publications including The Horses Hoof, Equine Wellness, Natural Horse Planet as well as a contributing author for the 2001 United States Federal Mounted Border Patrol Training Manual. For the last 37+ years, she has maintained healthy hooves with natural trimming on thousands of horses and specialized in pathological rehabilitation hoof care for the last 18 years. She and her husband John keep a small herd of their own equine in NE Connecticut and continue to offer consults for horses in need. For further information please click here: www.thepenzancehorse.com
Gwenyth is available for freelance assignments, contract work and consulting.