eden
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Post by eden on Mar 16, 2009 15:56:57 GMT 1
The navicular bone lies on the back of the coffin bone, but I know not much about it really, a friends horse has had it many years and is still ridden I think she has de nerved her horse?? does this help? What causes navicular in the first place? is it partly poor conformation?? This is the one lameness that I never really knew about when gr owning up, but a few friends horse had it!  XXXXX |
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Post by maggie555 on Mar 16, 2009 16:40:01 GMT 1
Hi eden,
I'm not an expert, but here is what I've heard:
"Navicular" is short for "navicular syndrome" or "navicular disease". I think lately, "syndrome" has been more in use, indicating that there's several contributing factors, and often no clear cause. Basically, a horse with navicular has heel pain, or pain in the back of the foot. To diagnose navicular, the vet will block the nerves to the back of the foot. If the horse is then sound, it may be navicular. On x-ray, changes to the navicular bone can sometimes be seen (small holes or rough edges on the bone). But most of the time, it is not clear whether this is the cause of the pain or a result of stress to the area. Since a tendon runs across the navicular bone, having a rough surface is bad. I don't think there's a definitive answer about where navicular comes from, or why.
Some people in the barefoot community think that navicular can result from bad shoeing (or bad trimming) that limits the normal function of the foot. The horse's foot is quite complicated inside, and many structures have to work together to absorb the shock of hitting the ground without damage. If this function is impaired, long time wear and tear could lead to pain in the back of the foot.
I think the outlook for a navicular horse is probably worse if boney changes can be seen on an x-ray, compared to a case where heel pain was determined only by nerve blocking.
Personally, I've heard from people whose horses fully recovered with a change in hoof care, but also know a friend whose filly got navicular at age 2. In this case, I'd have to think that conformation played a role, as she was never shod or ridden.
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eden
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Post by eden on Mar 16, 2009 16:43:22 GMT 1
Thats very intresting, thanks for that. In the 2 yr old case well conformation had to be pretty bad.
x Thank s
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Post by mandal on Mar 16, 2009 16:56:13 GMT 1
Gosh I really MUST bog off!! ;D I personally have no experience of navicular. Pete Ramey feels it is due to toe first landing causing friction on the tendon which overtime leads to bony involvement. In his DVD series he sights experiments done I think in the 1970's (think it may have been a couple of decades earlier actually. ) where cadaver hooves were attached to a mechanism where they were repeatedly exposed to heel first and then toe first landings. No damage was noted with heel first landings but it was noted that damage to the ligament/tendon (can't remember exactly) always came before damage to the bone on the toe first landing ones. He also has a model with pulleys and string attached where he shows clearly the unnatural forces that occur with constant toe first landing. I haven't got my set here atm to check and of course this is the only explanation that I know of that makes sense to me. I don't believe it's a standard explanation. Mta... Talking of DVD's, have you watched that Vid yet eden? ;D |
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eden
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Post by eden on Mar 16, 2009 17:03:26 GMT 1
mandel I'm watching it tonight will update you in morning, runs and hides under a large rock! lolxxxx
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Post by maggie555 on Mar 16, 2009 17:04:14 GMT 1
Hi mandal,
good point - I forgot about that (seminar with Pete was a couple of years ago...).
Still, I wonder how my friend's filly fits in with that theory? Even if she didn't get a good trim for those first two years of her life, I can't quite imagine that she'd be able to do so much damage due to toe-first landings in such a short time (and with low bodyweight, no rider). I would imagine that hoof/pastern conformation must have played a role somehow.
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Post by mandal on Mar 16, 2009 17:05:09 GMT 1
LOL eden loads of witnesses now!  MTA as I didn't want to up the thread... Apologies to you eden if I've been a bit of a bully about the video...  |
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Post by mandal on Mar 16, 2009 17:12:59 GMT 1
Still, I wonder how my friend's filly fits in with that theory? Even if she didn't get a good trim for those first two years of her life, I can't quite imagine that she'd be able to do so much damage due to toe-first landings in such a short time (and with low bodyweight, no rider). I'm not sure either maggie555. Pete R does say though that in his opinion damage or rather underdevelopment begins in foals at an early age if they don't have enough movement and regular trims. I think the toe first landing comes mainly from soreness in the rear part of the foot eg. thrush, immature digital cushion,lgl etc. so in theory the weight of the horse etc. is to a large extent irrelevant in this scenario... I'll be interested what others think about a youngster with navicular, I've no idea really as I've only really learned about Pete Rs' explanation.  Mat... here's a link to an article on Navicular on Pete r's site. I haven't read it yet so if it's totally different to what I've already said I apologise to Pete for any misunderstanding I may have caused. www.hoofrehab.com/end_of_white_line_disease.htm#Navicular |
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eden
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Post by eden on Mar 16, 2009 17:20:59 GMT 1
This is very intresting, many factors then.
Mandal yep!! x
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Jane
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Post by Jane on Mar 17, 2009 7:35:34 GMT 1
My understanding (I have a project navicular mare, cavities in the bone show on x-ray) is that the digital cushion changes in nature, becoming weaker and not absorbing shock. And/or the blood supply to the navicular bone is restricted, bringing about the changes to the bone itself. Toe first landing is due to the heel pain... chicken and egg situation there, I think... I view that as sympotmatic rather than being a cause.
This condition very often exists in cases of bad farriery/trimming where the heels are high/contracted. This was certainly the case with my mare.
My approach now is excellent barefoot trimming courtesy of a local trimmer, bodywork to help restore circulation in the hooves, good nutrition with trace minerals all catered for, plus glucosamine/MSM for soft tissue regeneration (we hope!).
A skeletal expert, Sharon May-Davis, has indicated that there is no reason why the cavities should not fill in with all the causal effects addressed, as the bone is a living tissue also. We are in experimental territory, as the vets wrote the horse off 3 years ago and she was due to be PTS (I've had her only since last November).
She is now walking heel first and galloping up a steep rocky slope in the mornings, often with a buck thrown in for good measure. She is ready to be ridden again. I suspect there will be ongoing weakness in the feet, but I'm sure she'll be very happy having a life of trail riding with me.
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Post by Yann on Mar 17, 2009 10:55:51 GMT 1
My laymans understanding of Ramey's theories about toe first landings and navicular are as follows: a) A heel first landing draws blood into the hoof due to the correct expansion of the hoof capsule on landing. This also assists with shock absorption. Toe first reduces this effect, and coupled with things like shoes and long heels reduces the amount of blood flow in vital areas. b) The deep digital flexor tendon tightens after the foot lands and the fetlock joint descends towards the ground. In a heel first landing the tendon is loosening as the fetlock starts to descend, toe first it is still tightening which tends to apply an incorrect shock loading to the navicular area. Combine that with reduced blood flow and you have a recipe for problems. Hope that makes sense |
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eden
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Post by eden on Mar 17, 2009 11:05:30 GMT 1
yep thanks yann.x
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Post by mandal on Mar 17, 2009 11:12:24 GMT 1
Oh Yann... obviously only part of Petes' theory stuck in my mind then (well I like to keep things simple!  ) I'm off to read that article on his site now.  Interesting Jane, I have obviously not taken in the blood flow factor.  Mta... I hasten to add that my understanding is very laymans!! |
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Post by amelia on Mar 17, 2009 13:07:56 GMT 1
ooh this is fantastic - I have homework for my shiatsu course and one of the questions is on Navicular - I'm just about to start answering it so any more info muchly appreciated!!
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Post by Susan on Mar 17, 2009 14:06:25 GMT 1
My own experience is a good one of a friend mare who at 5 just backed had intermitant lameness and after much tried and failed in trad shoeing went for Cytek, That seemed to work for a few years then it started to show its face again and there was only one choice left open and that was to take the shoes off. Her vet was not happy as he wanted eggbars.. he agreed to go with her plan. It took about 4-5 months of pads/using boots to eventually she was given the all clear by the vet and pronounced sound.
WE have discovered that Cytek although helps in short term the principle shows issues longer term. I know that one. But reality was given nature to repair and correct trimming ( she had a KC Trimmer) it was a good choice for her. Sadly the mare had other arthuritic issues and is now retired about to foal. But her feet are great.
Navicular is more often then not man made through incorrect balance. Long toe, crushed heels or short upright feet or what ever is not what the foot needs to be correct then the navicular bone is being stressed incorrectly so it will wear and so will other parts of the foot joints and tendond and ligaments.
Like any well made engine if something is out of balance other parts will show wear and tear not designed to have and not function correct. The implications will then go through the whole bady.
Few horses have comformation issues that I believe cause as much navicular we hear about. I am not saying shoeing is the evil but one caused by man when the foot is allowed to not be as it should in that shoe.
I have only heard of one case of navicular in an total unshod horse but I didnt see the foot and how it was trimmed to know if that was also out of balance.
It has been mentioned earlier in this thread of a 2 year old and it may be it has a real conformation problem.
If you look at the trans pics of Zac you can see how that foot has been allowed to become so wrong by the person shoeing and now how it is returning to a more correct balanced foot, to see what can be damaged by man and repaired by nature with mans help.
It would appear man still has a lot to answer for..
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