Posted by Jonathan Cohen DVM on July 29, 1999 at 00:12:26:
In Reply to: Re: correct shoes for navicular? Patty, please help posted by Patty Stiller on July 28, 1999 at 22:36:41:
: : Patty, is there any way you could post or refer any of us to the studies you mention . . . ?
: : : : : : Hi all, I have a question regarding a QH I shoe. I have only been shoeing for a short time, and a new client with this Qh calls. Says she cannot get a farrier to help her horse. He has been diagnosed with navicular by the vet, was shod with eggbars when I got there. I have no idea what tests the vet did, but the owner was told the horse would have to live in barshoes. Now when I examined the horse, I noticed he had a shorter front leg from the other.I figure if the barshoes aren't working, lets start with the basics and work from there. I shod him with plain wide web shoes and padded the short side to match the other. Horse was fine at a walk and trot but could't do any other gates with lameness.(Horse is shown in western pleasure). Next shoeing I put on a heeled shoe with a rolled toe, still padding the short leg to match. The horse has gone fine since, no lameness, and has taken 1st, and 2nd in the last 4 shows. Now the problem I have, was this a navicular problem or did the vet give wrong diagnostics? also I attended a clinic recently and the person lecturing told me you should never put heels on the front of a horse. How could this be wrong if it helped him?
: : : : : : thanks,
: : : : : : jeff
: : : : : Jeff,
: : : : : The horse may well have navicular. By putting the heels on the foot, you may have raised the angle just enough to help the horse for the time being. You may of also help by rolling the toe, takeing some more of the pressure off in the stance phase of movement.
: : : : : Navicular is very hard to call, and what works on some horse may not work on others.
: : : : : As for heels. I never shoe with heels unless looking for traction, I might suggest a wedge shoe next time at the same angles the horse is now set at. In time you may also need a bar of some type for additonal support.
: : : : : You may also want to give the vet a call and talk about this horse. You may also want to take a look at the raidographs if any were taken.
: : : : : Ray Miller
: : : : Ray has excellent points. I feel there is no one particular shoe for any one lameness, but there ARE basic *principles* to be applied.How well the *principles* are applied affects the success of whatever shoe is used.
: : : : Navicular problems arise from several factors, the MOST important being the distance from the tip of the coffin bone to the point of breakover.(radiographically it should be 1/4 inch. That is usually somewhere in the range of inch and a quarter to inch and a half from the apex of the frog.A couple of engineers have calculated that bringing the breakover rearward a centimeter and a half reduces the maximim stress on the deep flexor tendon at the moment of breakover by 45%. That is a bunch. Other factors as well are important, such as the correct boney alignment especially in the coffin joint, and the position of the back of the heels. Som horses also have inherently bad digital cushions inside the foot. In a recent study at Michigan State University so far EVERY foot that had navicular pathologhies had a poor quality,fatty digital cushion, while the feet that had no navicular pathologies had a strong,elastic, cartilaginous one.it may be that those weak feet may need some help forever, but bar shoes may not be the answer.
: : : : You addressed a couple of problems with your shoeing. You raised the angles, and brought the breakover back with the rolled toes. The bar shoes may have helped, but if the breakover wasn't addressed, no amount of shoe sticking out behind the heels will help.In fact too much may hurt.You are on the right track, and I agree wtith Ray that a wedge shoe (or hard wedge pad) would be better than a heeled shoe.Patty
: : : In 49 years of being around horses and 12 years of shoeing I dont think I have seen more than a dozen horses with a significantly shorter front leg ... that can cause all kinds of problems ... as for the navicular I agree with Patty and Ray ... If the heels are underrun at all I would go for the wedge shoe vs a hard wedge pad
: : : Scott
:
: The most significant study that comes to mind is published in the August 1998 American Journal of Veterinary research. The title is (hold on to your hat)
: " Functional anatomy of the cartilage of the distal phalanx and digital cushion int he equine foot and a hemodynamic flow hypothesis of energy dissipation." It was done by Dr.Robert Bowker DVM, PHD at Michigam State,along with Kimberly K Van Wulfen DVM, Susan Springer, BS and Kieth Linder DVM.
: Another useful paprer was presented by Dr Bowker in collaboration with Dr Barbara Page,DVM, and farrier Gene Ovnicek. It is titled "morphology of the hoof wall and foot of feral (wild) horses versus that of domestic horses".
: Dr Bowker also went into more detail about the hystological changes in the navicular/coffin joint area and consistensy of the poor digital cushions in a talk at Colorado State last year that I attended. I do not know if that information has been formally published yet, all this is so new and uit takes a LONG time to get research accepted for publication in the vet journals.
: There are also published articles in AJVR by Dr Bowker on other vital anatomical structuresm such as the receptors under the back of the frog.
: Patty
I just shod a horse the other day, actually it was just one foot but that was enough for me. Anyway I know with a 100% confidence that this horse is and will be navicular; it's broken in about five pieces. My point being that as a vet I'm still very uncomfortable labeling a horse as navicular. For anyone that doesn't think that the deep flexor tendon is a really important part of the whole nebulous realm of navicular diseases, syndromes, etc. they should see these radiographs. The broken smaller half has been pulled up and away from where it used to live at least an inch.