Conference noted::equitation

    Maybe my story will help.  My, now 22yo, gelding was diagnosed with
    navicular when he was about 11yo (before I got him).  Similar story to
    yours, very lame, no obvious cause, 100% sound with the block.  He was
    x-rayed for navicular.  He showed "navicular changes".  Diagnosis:
    navicular.  He is shod with wedge pads.  I come along 1 year later.  I
    start exercising him.  Never takes a lame step.  After 6 mo they offer
    to give me the horse (1$, some say I spent too much but that's a
    different story ;-)).  I read up on navicular and, based on what I know
    about his case (which I considered inconclusive) I take him.  Now, 10
    years later that old boy has never taken a lame step.  I continue to
    shoe him with wedge pads. I had a new vet out last year and I ask
    about the original navicular diagnosis.  He pressure tests the horse
    and feels the horse does NOT have navicular. Unlikely he would have
    stayed so sound all these years.  His build is a classic one for having
    the disease.
    
    So, what I'm getting at is that this "navicular" diagnosis is not one
    of these 100% certain things.  Especially based on one lamness episode.
    I have no idea how long you would have to "wait and see".  I'm still
    waiting 10 years later. I'm now convinced my big guy doesn't have it. I
    keep him shod for it as a preventative measure since he'd be inclined
    toward it due to his build and previous occupation (event horse).
    
    In addition I have a small pony (10h) who has been off and on lame all
    the years I've had him (9yrs).  No one knows why, farrier, vet, etc. 
    *I* finally decide he just has tender feet so I buy him little tiny
    Easyboots for the front feet.  You've never seen such a happy guy.  He
    doesn't have to wear them all the time but I have him wear them when
    the footing demands it and often after he is trimmed.  I haven't seen
    him take a lame step since I got them last November. You can't tell my
    pony his feet don't get sore or bruised.
    
    FWIW that's my experience with "undiagnosible" lamness (i.e. no foreign
    object, no abcess, etc.)
    
    Good luck.    Jeannie

    Horses don't always show typical symptoms with lamenesses.  My horse
    was lame up front last summer, with swelling and heat from the the 
    fetlock joint to the knee.  No digital pulse, negative to hoof testers
    and no heat in hoof.  Positive to ankle flexion.  Vet diagnoses ankle
    sprain.  A couple days later, he blew an abcess out his heel -- swelling,
    heat and lameness disappeared immediately. 

A couple more questions:

Is the horse shod now?
Did the (local) vet - the one that gave the navicular diagnosis - take any
	radiographs (x-rays) of the front feet?
Was this horse in a turnout situation that could have been unkind to his feet?
How old is the horse in question?
Can you have this horse for some trial period before you have to make a full
	committment to it?

    Yes, the horse is shod now.
    No, no more xrays, I've already spent enough on this horse, besides, 
    the vet said she's seen horses have terrible x-rays and never have a 
    lame day, and vice versa.
    Turnout is ok, not great, he also runs a lot whinneying when I take my
    other horse out.
    The horse is eight.
    I can keep him for a trial longer, but he's a real sweetheart, we can
    really get attached.
    
    Sharon

    re .2
    
    Yeah, those abcesses can masquerade as *anything*!  One of my horses
    used to get them all the time, apparently from stone bruises, until we
    moved to a place with less rocky paddocks.  And his symtpoms would be
    very different from one bruise to the next -- not surprising since they
    were in differing locations in his hoof.  Once we though he had a
    fetlock strain, another time it seemed like navicular.  Then the vet
    and I learned that he was just having his yearly abcess...
    
    -ellie  

    I was just reading an article somewhere (I can't remember where) of a
    study that some Veterinary school did on Navicular disease and how they
    looked at navicular bones of horses that should have been absolutely
    dead lame and had never taken a lame step, and vice versa (the study
    was done on dead horses).
    
    Anyways, I have found that veterinarians tend to differ on opinions on
    the same horse.  My horse was off 6 months ago due to a quarter crack
    originating at the coronary band and she was just a tiny bit off but
    enough that I could see it so I had her checked out by one vet who said
    she shouldn't be off from the crack and gave her a block and diagnosed
    navicular disease.   I have another vet (# 2) look at and X-Ray again 4
    months later and tells me that yes, it could be quarter crack and we
    change her shoes a bit and she is sound from then on.   4 months from
    that X-Ray (this is the 3rd set of X-Rays) and the horse is still sound
    but someone would like to buy her and this vet says Navicular series is
    in the "upper range of normal" and COULD get Navicular disease!  This
    vet took 18 X-Rays (glad I wasn't paying that bill!) and also saw some
    fusion in her left hock (not sure which bones) again, NEVER lame.  
    According to vet #3, this (hock fusion) could be a problem sometime
    down the road as a Dressage horse but would vet horse out as a pleasure
    horse.   The woman who wanted to buy her was a beginner and several
    years away from any upper level dressage work.  Oh yes, and when a hock
    fuses the horse will probably go off on the opposite front while it is
    active.
    
    Karen
    
    
      

Since you can keep the horse for a while longer on trial,  I would 
pound on him (use him) as much as possible during that time.  If he does not 
go lame with the heavy use, chances are, he may be fine.  As I've come
to realize, every sound day you get with a horse is a gift, and there's 
no way to predict what will or will not hold up.  You can only make
educated guesses.  Some of us get more gifts than others.

He could have been reacting to having very short feet, either from 
wear or from being trimmmed just a little too closely.  If that was the case, 
time will heal as the foot grows.

If it's navicular that's bothering him, the heavy use should bring it back, if 
it's to a degree that would hinder your normal use of the horse.  

    
    i have a few questions,  what exactly is navicular disease, and 
    What is the price of xrays, oh and one more thing please, 
    What is the approximate cost of vet checks.  Very interesting topic
    
    
    Thanks alot
    
    Karen

    I'm no expert but the navicular bone is a small bone in about the
    center of the foot.  From what I've learned just recently, Navicular 
    disease is a soreness in this area, caused by the burstus? sp?, the
    tissue which covers the navicular bone.  If the x-rays show bone
    deterioration then navicular soreness may result, BUT not neccessarily,
    and vice versa.  X-rays are only a guideline, but naturally if the bone is
    rough and deteriorated, the burstis may be or will be damaged.  
    If a horse is inactive for a period of time, the burstis may heal but
    after use again it will break down quickly, (this is what I was told
    may be the reason my horse vetted out just fine and then went downhill
    so fast, but how did he recover so quickly?, I don't know)
    
    My vet check basic price was about $100. My X-rays cost about
    $45/hock but I can't remember if that was one picture of each or two. 
    I do know that more are taken when the front feet are x-rayed
    (generally). Add the farm call in separately ($25 - 30).
    
    Sharon
    
    

  You mentioned that your horse went sound after blocking... did your vet do
  a partial block first?  Or a full block?  

  My horse went dead lame last summer... DEEP STONE BRUISE.  I had farrier out
  (who claimed all was well, no sign of bruising, no reaction to hoof testers).
  Then I called the vet.  He attacked the foot with the hoof testers, watched 
  the horse go and did a partial block... horse went *very sound*  (leaping
  around, happy, etc - big change from the depressed, ouchy critter I led out).

  Vet dug around and though he didnt' find an abcess, he did find bruising.
  Soaking and easy boot for a couple of weeks (to draw out any abcess), before
  shoes with pads.  

  The partial block wouldn't hide problems with navicular changes, coffin bone,
  coffin joint, or higher on the leg.  

  Lastly, the fact my horse didn't have pads on to begin with was my fault.
  I should have realized that the footing was getting hard and the rocks were
  surfacing in his pasture.  I should have insisted on pads.  

  If your horse was accustomed to softer footing during turn out and work than
  he's gotten since his move, he could be ouchy from the change.  Pads may be
  in his future.  A 2nd opinion to your local vet diagnosis may also help...

			Good Luck!

    I just re-read your base note.  It seems strange that the horse had
    very short feet, but was due for a trim in 1 1/2 weeks.  It also seems
    very possible that he just got trimmed too short originally and was 
    sore and then maybe got a stone bruise.  They are not always real 
    visible.    
    
    mary

(disclaimer: I'm not a vet, I don't play one on TV, I just happen to have been
doing some light research...)

The navicular bone is indeed a small bone in the foot.  Due to it's location, it
tends to be the major shock absorber of each footfall.  Character cell terminals
don't lend themselves to drawing, but the *general* location is


		   /
		--o

where -- is the coffin bone, o is the navicular, and / is the lower pastern
bone.  If I remember correctly, it is held in place by the low branches of
the suspensory.  Every time the horse puts his foot down, this joint flexes to
some degree, and the navicular bone absorbs much of the impact from the pastern.
Being the 'hinge' in the joint, the navicular bone takes a lot of impact.

Navicular disease is, in layman's terms, osteoporosis of the navicular bone. 
In other words, the bone develops lesions, or holes in it. It starts life looking 
like a dense sponge.  As navicular disease progresses, that sponge becomes less
and less dense, and less able to absorb the concussions of each footfall.  Vets
say that a horse has 'navicular changes' when the x-rays show the bone becoming
less dense. (The bone becoming less dense is a natural aging process, so 
some changes are expected as the horse ages, but in some horses degeneration 
occurs faster.)

Common treatments for navicular disease include, but are not limited to,
1) Changing the angle of the hoof.  By raising the heel, you decrease the 
   amount of direct concussion that the navicular takes, and redistribute it to 
   other structures in the hoof.
2) Adding bar shoes.  This provides extra support for the entire hoof, 
   distributing more of each footfall concussion to the surrounding tissues.
3) Various regimens of the drug Isoxuprine.  This drug is a vasodialator (opens
   the blood vessels).  It basically increases the circulation in an area that
   has notoriously poor circulation anyhow.
4) Nerving the horse.  This is cutting the nerve that goes to the navicular 
   (heel) area.

Common wives-tales surrounding navicular disease:
1) Quarter horses get it.  (Navicular is not confined to quarter horses, although
   there may have a higher occurrence in this breed than in others.  This may be
   due to the breeding practices of small feet in relation to the size of the
   horse (smaller area to disperse concussion over).  Just because you have a 
   TB, or a <insert your favorite breed here> doesn't mean you don;t 
2) Big feet won't develop N. (not true)
3) I won't ever be able to jump my horse again (Not necessarily true. There is 
   nothing that determines the rate of degeneration, other than periodic x-rays.
   If you find a treatment that works well for your horse, you can do whatever
   you like with him as long as he remains comfortable.  You need to find that
   out for yourself)

    re: .6
>                                                   Oh yes, and when a hock
>   fuses the horse will probably go off on the opposite front while it is
>   active.

    Can you expand on this ?

    I think you just diagnosed the TB I'm 1/2 leasing.
    She had the vet inject his hock so it would fuse faster & did
    acupuncture for a sore back.
    He was getting better until he got new shoes without pads about
    2 weeks ago.  Now he's off in front.

    Bill

    Thank you, Cathy, for the detailed info on navicular.
    
    One thing I would consider, too, if I were the base noter, is what I
    was using the horse for.  Light pleasure work on soft ground would seem
    less likely to cause problems than heavy training.
    
    FWIW, I've known one horse for 2 years that I've just learned has
    navicular disease -- I would never have guessed that he had a problem. 
    Turns out he was diagnosed several years back...
    
    mary

Bill,

Hind end lamenesses are more difficult to diagnose. Head bobbing (normal
sign of lameness) is more perceptable when the front end is sore, although
you may see it to a degree when the hind end is sore.  It is easier to see 
hind end lamenesses directly from behind (difficult to do without a second 
person). Usually lameness is seen at the trot, which is a diagonal gait. If 
the hind is sore, it often looks like the opposite front is the one with the 
problem.  Horses  also change (often imperceptably) the way they hold or 
carry themselves when something is bothering them.  This often causes 
compensatory lamenesses in other parts of the body.  Flexion tests and blocks 
are generally used to try to pinpoint which joint the soreness is in.


kathy

    I know of several horses with navicular who have been used as light
    pleasure/trail horses for years with no problems. One in particular
    has just recently (last fall) been retired from being a lesson horse
    at Brindle Ledge Farm after many years (his name is Garfield, for any
    Brindle Ledge people here, I know he was quite popular there). He is
    now stable at my neighbors house, where after the winter off and 
    corrective shoeing he is doing fine and frequently does 5 - 20 mile
    trail rides with no problems, his 'mother' expects to get many more
    years with him this way....which actually surprised me a little, I
    trailered him home for them last fall, he was barefoot and dead lame
    in both front feet, he looked in so much pain at the time I wondered
    why they'd adopted him at all, but it seems to have worked out.
     

    Well, he went lame again, if we start to use him (lunge him or
    anything), he might not show the lameness then, but he's very sore the
    day after and the next few.  I guess he'll be going back.  
    
    Thanks for all the advice, 
    Sharon