pedal osteitis and buckling knees

[plepera1]

I have an 18 yr old TB mare, that I’ve had for 7 years. She was a rescued horse who among other things had probably foundered at some time in the past. She was diagnosed w/ Pedal Osteitis about 4 years ago. It was diagnosed after a lameness from a “hot nail”. I presumed it was a long-standing chronic condition since I’d only ridden her lightly, no jumping and only rarely on short trial rides.
She then was shod w/ eggbar and full pads for about 6 months. She seemed fine after that and so we put her back in regular shoes.
Now three years later, after a recent bout of lameness and buckling of her knees, the vet did a PD and then abaxial block and she was about 90% sound. It was determined, after xrays, that the pedal osteitis was probably causing pain in the front feet and was most likely the cause for the buckling knees.
However, during the episode of 4 yrs ago, her knees never buckled, so I’m wondering if the pedal osteitis is the culprit or could it be age combined w/ her over-the knee conformation? Or all three conditions?
Even leading her from the pasture, where she’s been 24/7 (but in winter she comes in at night), I notice her knee, usually the right, buckles on occasion. In the saddle, I had noticed it mostly at a leisurely walk, but occasionally at the trot - often when going into a turn, but also on the straighaway.
The vet said the xrays also showed the channels in the navicular were slightly larger than normal-so there’s some deterioration there also. He recommended wide-web eggbars w/ rim pads which she’s been in for the last 6 weeks. However, at the clinic, the shoer didn’t have wide web eggbars so he put regular eggbars on until the next shoeing.
But, I have three questions at this time.
1) Do you have any other suggestions for what could cause the buckling knees? I know it might be difficult to offer a theory since xrays were done only of the feet. But if the buckling knees are a condition separate from the pedal o, say due to age and over at the knee conformation, is there another shoeing method that could help ameliorate the condition?
2) Wide web eggbars are supposed to provide a broader area of support for the foot. However, if only the hoof wall rests on the shoe, why the need for a wide web? Is the extra width there for any secondary contact of the sole during loading? I don’t know if I phrased that correctly, but hopefully you understand what I’m asking.
3) The vet said no new bone would develop to fill in the deterioration around the edge of the coffin bone. Is that true? You may think this farfetched, but I was wondering about Fosamax. I know it helps grow new bone in humans, altho, I don’t think they’ve perfected it to the point where you can direct the new growth to a specific area. Is there anything comparable for equines - or is the vet correct about the coffin bone incapable of growing new bone?
I’d be grateful for any light you can shed on the above. Thanks. Pat

[Phil Armitage]

I shod a few horses that were bucked kneed like this, they all foundered, and developed pedal ostietis. My eperience is the problem is chronic and all you can do is try to make them comfortable and work them easy if you can at all, personaly I do not think it is good to ride horses like this. There feet cannot withstand cuncussion like a sound horse can. Pedal Ostietis is damaged bone on the bottom edge of the coffin bone, not only is the bone damaged the live sole and vascular structure is also damaged and compromised, circulation is very poor in this situation because of pressure on the viens in the that area. Pedal is another term for the coffin bone, ostietis is Ostiets that develope on bone when it is bruised from cuncussion. When a horse founders and the coffine bone (Pedal Bone) rotates, the front edge of the bone is closer to the ground and the sole is thin, so the bone gets banged up and it is painfull and internal tissue between the bone and the sole is also damaged. I am not sure, but I think the bucked knee is probably due to compensating for the pain in the feet (makes sense anyways) and there is probably degenerative joint desease in the knees by now. The coffin bone is very porous and it is not like other bones in the body, so I do not think it can regrow bone from the treatment you mentioned like normal bone can, it can remodel and I beleive the ostiets can dimish if the cuncussion is eliminated, however this is difficult to do if the bone is chronicly rotated and the sole is thin. Is this a chronic founder case and what is the thickness of the sole protecting the bottom edge of the coffin bone? You can provide protection and support by shoeing. The idea is to use frog support and no sole pressure in the toe, horses like this should be shod even if they are not worked just to keep them comfortable. Focus on reducing concussion, by shoeing, only do light work on soft footing. Probably the most important thing to find out as far as trimming and shoeing goes, is to find out what the sole thickness and find out what the angle of the coffin bone is so that your farrier has more information. Also keep in mind, this horse is 18, been dealing with pain for a long time and other problems could have developed in her body from compensating as she gets older the old bones tend to get more and more tired and she may need to be retired and just allowed to enjoy her last few years stress free. Sounds like you got a lot out of her and that she is a great horse. Good luck and best wishes

[TE Couch]

very often in foundered horses and horses with too high a heel and or contracted hooves the horse will go "over at the knee" and bear weight in it's extensor tendons ( in front ) - the flexor tendon ( in rear ) will be "pulled" up by the muscles in the shoulder and the horse will suffer muscle pain as well - with the coffin bone pressing on the sole corium the bone will erode, it will not regenerate and the more loss of bone the horse suffers the less chance for a tight laminar connection between the coffin bone and hoof wall. In this steep or rotated position, the cir***flex artery that feeds the sole corium will be "pinched" off and so the sole cannot grow well. This is a chronic condition caused by incorrect hoof form and not age related ( the cause is not age related, the pain is not from bone loss, this is a sympton ) Post photos if you can, side and sole views.
TE
This is my experience and opinion as I have not seen your horse.

[plepera1]

Thanks to you both for you responses. You've given me a clearer picture of the condition. I want to do what's right for my mare and figured retirement time was fast approaching - I just was hoping it wasn't this soon.
My farrier is coming out Saturday so I'll discuss this w/ him-and try to get some photos - at least for educational purposes.
But so I am clear - when you say frog support are you suggesting a heart-bar shoe or a wide web with a full pad that has frog support? She's in an eggbar w/ rim pads now.
And regarding the wide-web shoe - if only the hoof wall should be sitting on the shoe, what's the advantage of the wide-web?
And what about "sneaker" shoes? A friend has her older mare in a pair and swears by them. Have you any experience w/ these and what's the advantage over the traditional eggbar w/ pads?
Also, when the first flare up of the condition occurred 4 years ago, I was regularly painting her soles w/ iodine to toughen them during the wet winter. Is this still a good idea?

Thanks. Pat

[calshoer]

Pedal osteitis is a very common result of the laminitis, (poor foot form or not).Thoroughbreds are particularly susceptable to it even if they have terrific foot form, just because they inhrently lack sole depth and supportive cartilage inside the foot so the bone gets traumatized over time. Especially if they raced.
During laminitis, the circulation in the foot is compromised for a time and the fragile bone edge bone will deteriorate due to lack of blood supply. This happens even in feet with low correct heels , not just tall heled ones.
Although the pedal osteitis needs special consideration in protection from more ground trauma to the bone, it is probably not the cause of the knee buckling.

Horses with long toes often can buckle over inthe knees, as the check ligament behind the knee is pulled too tight and may get painful. Insure that the breakover point is where it should be, near a spot directly under the tip of the coffin bone. This will mean a rolled or rockered or set back type toe on the shoe.
Coffin joint alignment is another common result of part of the long toe problem.If the joint is "broken back". the knee buckling may be one sign.Coffin joint pain due to internal joint misalignment may have blocked out with the abaxial block. If the joint is not aligned after the breakover is addressed, she may need the help of added frog support(to better support the coffin joint and align it ), along with posibly wedging. And the farrier can NOT rely on the sighting of the foot-pastern angles to asess proper joint alignment. It takes specially set up lareral Xrays. The external hoof angle can be extremely decieving if afarier is not trained to see subtle hoof distortion.

I have seen so many buck-kneed horses "cured" by just rebalancing everything in the hooves that it is ridiculous that so many veterinarians do not look at those inernal hoof balance issues and how it relates directly to the symptoms in the leg above. Same thing happens with "sickle hock" hind legs. Completely change the feet and they will often change to a correct leg stance. In as little as about ten or fifteen minutes sometimes.
Patty

[Ronald Aalders]

Although I'm not 100% sure I think that horses that devellop bucked knees just try to get away from the pain caused by P3 pushing down on the sole. (Whatever caused that situation, laminitis, clubfeet, low heels long toes) By relaxing the carpus DDFT relaxes too and the crushing of the cir***flex vessels is reduced.

I've seen this on several feet. Steep ones, but also on low heeled horses. So far a banana on the low heeled ones always got rid of the buck knees. Immediately or in a week or two. On the steep feet I drop the heels and put a # 2 wedge on if the buck knees don't straighten out enough. (Really we're talking derotation and loading of the heels here!)

Like always, balance is everything.



Ronald Aalders

[plepera1]

Ronald - thank you for your response. My mare was a rescued horse so I don't know much of what happened before I bought her 7 years ago, but the three farriers who have shod her over the years feel that she must have foundered at one time and X rays do show P3 at a different angle than the hoof wall.
She has low heels, but I've always had her toes rolled to facilitate break over.
Right now I have a new shoer who convinced me to try the natural balance shoes - she's only shod on the front - which he placed well back so that she would break over faster. He indicated this would have the effect of getting her off her toe and onto her heels. I gave her a couple of weeks to get used to the new shoes and then got in the saddle, mainly just walking her in the arena. That was about 3 weeks ago - at a slow walk, her knee buckled once; I trotted her for about 3 min and she didn't buckle. I'm in a quandry. I haven't been riding her because I don't want to risk injuring her. Out in the pasture I notice she gallops around and she doesn't look as tho she's in pain nor do I see her knees buckling.
What is this "banana" that you refer to? Is it a bar shoe? How does it work?
Also, my other concern is the changes the vet noticed in her navicular. He didn't seem to think the changes were of major concern, but I would like to stave off any further changes. So, by getting her back on her heels more it seems I am putting more stress in the navicular region - sorry I'm not more knowledgeable about anatomy - would that be the DDFT?
I'd appreciate any further insight you can offer. Thank you. Pat

[plepera1]

Patty - When you suggest frog support are you referring to heart-bar shoes or pads w/ frog support. My farrier is reluctant to put heart-bar shoes on because he feels more damage can be done if the bar shoes aren't set properly. Pads w/ frog support are an option he is comfortable doing, tho. But the issue of wedging - if she has been too much on her toes - wouldn't wedges just put her that much more on her toes?
He has put on natural balance shoes and set them back so that she breaks over faster and so eventually the load bearing is shifted back towards the heels. I've heard pro and con regarding the natural balance and to be perfectly hoest I don't know that I truly understand exactly what they are supposed to do.
Any further insight would be appreciated. Thanks. Pat