Q: My horse is a 6 year
old Appaloosa Mare. She has small feet with steep walls. My vet is concerned
about the steepness of her wall and her contracted heels. Her left forefoot has
practically no frog left. My vet feels this can be corrected with shoeing. My
farrier feels it is difficult to correct these things once a horse has matured.
Both the vet and farrier are wondering about navicular. How can I tell? What
should I do?
A: Diagnosis of navicular
disease can be difficult. Since navicular usually rears its ugly head at about 7
years of age this puts your 6 year old horse in the risk category.
Generally in my practice if I suspect navicular disease, I begin by palpating
the navicular area of the frog with hoof testers. It takes an experienced hand,
but the horse's reaction to the testers will indicate the presence of pain in
that area, or the lack of it.
You can look for a "navicular waist" which is a contraction halfway
down the hoof wall, both medially and laterally, that develops in advanced
cases. Viewed from the front, a hoof with a navicular waist appears to have an
hourglass type shape.
Another test is placing the horse's foot on the end of an 8 foot long 2x4 board
so that the heel is on the ground and the front half of the hoof is on the end
of the 2x4. The opposite front foot is lifted and held while the 2x4 is grasped
and raised off the ground from the end the horse is not standing on. The acute
angle resulting from the raised 2x4 draws the deep flexor tendon tight against
the navicular bone. If pain is present the horse will jerk the foot that is
being held up and slam it to the ground (the person holding up the foot must be
extra careful!). A positive reaction to this test is a good indication that pain
is occurring in the navicular area. However, like all "navicular
tests" it is not in itself conclusive. The horse could be suffering from a
bruised tendon or tendon sheath in that area.
If the above tests are conducted by your farrier or by yourself and they prove
to be positive, the horse should be referred to a veterinarian for a posterior
nerve block and radiographs. Most testing done by veterinarians will either come
up negative or abnormal. The vet and you will have to decide what conclusions
you wish to draw. Oftentimes tests are non-conclusive. I highly recommend you
get at least two opinions.
In my years of shoeing and dissecting hundreds of feet from horses put down for
navicular, I have found that approximately 80% had bruised deep flexor tendons
over the navicular, generally caused by low heel, long toe syndrome rather than
actual navicular disease. With rest and proper shoeing these horses could have
been saved and returned to active service.
As far as straight walls and contracted heels are concerned. We either have a
congenital or a shoeing problem. If it is a shoeing problem the following
suggestions may help.
Shoe on schedule. Shoe with adequate expansion. Pad and pack the feet with
Forshner's Medicated Hoof Packing to restore moisture and apply a bar shoe with
frog pressure and rocker toes. Frog pressure can be accomplished where little
frog is left by using leather shims and/or hot glue built up to make contact
with the frog when the foot is loaded.
Keep your horse shod short but not to the point of sole bruising, and nail to
the front half of the foot only. Finally, thinning the quarters with a rasp from
the 3rd nail hole back will sometimes aid in relieving the contraction.
If navicular is confirmed you will need to have the bar shoe be a wedged bar
shoe, raising the heel about 2 degrees to take pressure from the deep flexor off
the navicular bone. Also if navicular is confirmed, do not
have frog pressure, and you will need to weld a piece of a horseshoer's
rasp into the bottom of the shoe to protect the navicular area from being struck
from below.
Be sure to give your equine practitioner and your farrier a copy of my
suggestions. My thinking is that with very straight walls, no frog left and
navicular suspected that the prognosis would be guarded.
There is one last thought that comes to mind and the word is Equilox. A farrier
with the knowledge and skills working very closely with a knowledgeable
veterinarian can sometimes apply Equilox, which is an acrylic imitation hoof
wall material, to relieve the stresses of support and allow the lower (distal)
half of the hoof wall to expand. See attached illustration. If the horse is
diagnosed positive for navicular, the appropriate shoe would be a bar shoe with
negative frog pressure.
| Sincerely, Geronimo Bayard The American Blacksmith Oakland, Oregon |
One method of shoeing for contracted heels but not for navicular. |
