What would cause calcification in a younger horse?

I'm curious as to why you had a full workup after four weeks if a prepurchase vet exam had already been performed?

At any rate, when tendon tissue is injured, cellular changes at the site of injury are what predispose the tissue to developing calcium deposits. There is typically inflammation present, but not always. The calcium is secreted from cells and develops into deposits which may remain there over an extended period of time and then eventually go through resorption, meaning that the deposits are gradually removed from the tendon tissue and absorbed into the bloodstream. During the resorptive phase the horse may exhibit increased sensitivity as this stage can be painful. The calcium deposit ultimately disappears gradually and is replaced by collagen fibers as part of the long term healing process, although in some circumstances surgical intervention (tenoscopy) may be required to remove them.

So, the calcification indicates tendon tissue damage occurred at some point in time and hasn't been resorbed. The damage could be from strain as when the tendon is overstretched, or from blunt force injury such as an interference injury, or from an infection, or just about anything that would cause damage to the tendon tissue.

Ultrasound exam of the tendon can be performed to evaluate the quality and stage of healing of the injury, and guide the vet in prescribing treatment and rehab.

Hoof rings are also called event rings, and can be from a variety of metabolic conditions such as when there is a change in diet or a period of fever, and aren't necessarily anything to be concerned about.

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Add....................... Here is a good article listing various causes for development of event rings that you may want to read through. As is noted at the end of the article, changes in hoof quality that cannot easily be explained relative to environmental or mechanical causes should be evaluated by a veterinarian, and not just a farrier. Farriers are not medical doctors and are not qualified to determine medical diagnoses..

http://www.thoroughbredtimes.com/horse-health/2010...

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Add 2..... It is relatively common. Hydroxyapatite is a crystalline calcium phosphate that can be deposited in ligaments and tendons, bursae or joints, and it can sometimes occur due to a disorder of mineral metabolism, but is often secondary to tissue damage.

This horse's history of having been used as a lesson horse, kids toy, and human endurance horse, being "broke too early or rode too hard too fast" could all have involved varying degrees of repetitive trauma to the ligaments and tendons that could have led to formation of calcifications.

When calcification of tendons or ligaments is seen, local trauma, impaired blood supply to tissue or necrosis (tissue death) are likely to have occurred. Deposition of calcium phosphate crystals is most likely to occur in the areas of the tendon or ligament with the least vascularization, meaning the areas where tissue has minimal blood supply.

The stage of healing would have to be determined with ultrasound or MRI exams. As a rule, exercise that improves circulation to the tissues will encourage resorption of the calcium crystals and formation of new collagen fibers to restore more tensile strength to the ligaments and tendons. Cortisone injections will speed up that process by breaking up the deposits so they can be reabsorbed. Once there is damage to a tendon or ligament, it never heals to be as strong and resilient as it was originally, but quality of healing can vary with development of more or less well aligned and functioning collagen fibers, and only a vet with proper diagnostics monitor progress and determine a prognosis.

I must advise that all this work-up should have been done at purchase. Xrays included. Vets do not have xray eyes. One vet missed it and the other is taking an educated guess. Only xrays will tell the truth of the matter, on the bone and any calcification.

Hoof rings are a sign of metabolic upset.. They are evidence of laminitc "events". They should be taken no less seriously than laminitis. The diet needs to be settled down to basics to see smooth growth coming down in the future. No grain, sugar starch etc. Minerals, hay, water, maybe limited grass. Something is in excess and its stressing her feet.

In the interest of healthy digestion, and hooves, she needs to get out of the stall and move. Use it or lose it.

A set of xrays are what's needed to really know on the calcification. The trick is to free up the use of her feet and get them balanced and using them properly So call in a Farrier and get the hoof balanced. It could very well be past hoof pathology that has caused this tendon problem. I would follow the advise of a good farrier with hoof in hand and if he had xrays in his hand as well, that would be excellent.

I would also speak to him about the rings and past diet and any damage it may have done to the hoof (stretched white line, dark and angry, bone low in the hoof or down on its nose. long breakover or in particular, long heels with the calcification problem. The dragging back legs can also be a hoof balance problem.

Hope this helps.....

I wonder why he did not pick up the problem on the pre purchase exam?

I would question his thoroughness.. I have seen and heard of a lot of joint calsification but not with the tendons. It would be great if you could show us some pictures if the problem is visaible with the necked eye?