Lobo the Laminitis case.

Welcome again,  This is a case of acute laminitis that we were called to look at late on the evening of May 29, 2011.  History of colic episodes the previous couple of days but now not wanting to stand and when does stand has typical laminitis stance.  Upon examination normal foot conformation no ridges but large bounding pulses noted in all four feet.  Placed in Nanric modified ultimates which raise the palmar angle 18-20 degrees and Lobo immediately began to show signs of comfort with licking of lips, less distress and standing up squarely on fronts.  He was still reluctant to move in a normal fashion.  Baseline radiographs are taken on this evening and have soft tissue parameters within normal range.  This is where many hoof care professionals are confused as no signs of bone displacement or rotation has occurred, but it is still very important to support this foot mechanincally with wedging to unload effects of the deep digital flexor tendon as the vascular compromise has likely began.  The idea that if there is no rotation it is no laminitis/founder does not hold true. This will also show how important radiographs on day 1 of  exam are so valuable when compared to the next visit 5 days later.  A baseline venogram was not performed as finances where limited at this point.

We returned to visit Lobo five days later and find he has been laying down the biggest part of the time which is probably to his advantage as all load is off feet and better circulation is allowed.  Radiographs on this day show significant soft tissue parameter changes with large increases in CE, H/L zones and decrease in sole depth.  Palpable ledge is noted on both fronts at the coronary band that is consistent with a sinker.  We performed a venogram at this point at no charge to client to further increase our knowledge of this case.  The changes in soft tissue parameters indicative of a moderate sinker are confirmed with the venogram with no perfusion at the coronary waterfall, face of coffin bone and sole under tip of p3.  Note even in this severe case the heels remain great perfusion.  The unloaded view is taken with the limb being held up which gives us an idea of what the perfusion may be while laying down with tendon and foot completely unloaded and some indication of what it would look like with  a tenotomy to completely release any action on the coffin bone. 

The venogram is performed in the modified ultimate which unloads the flexor tendon by 60 percent.  This also serves as a means to evaluate a certain therapeutic package.  If your plan is to restore healthy blood supply then you should be able to prove that the package is going to do that via the venogram.  This venogram suggest that the modified ultimate will not be enough to restore proper blood supply and that further mechanical release via deep digital flexor tenotomy would likely improve the situation as the sharp border of the coffin bone is cutting through the sensitive solar corium and its vital blood supply.  Several methods to prevent the bone from displacing are practiced but few have been confirmed and followed with serial venograms and radiographs to prove that they are unloading the circumflex artery.  The heart bar shoe is a positive force applied to the frog in order to antagonize the displacement of the coffin bone, but think about the tissue between the rigid heart bar and the coffin bone.  The solar corium with its blood supply that makes the horny sole that we can see and touch.  Obviously it has helped many cases but I think a further study as to it's affects on foot perfusion in a laminitis scenerio via serial venograms and radiographs is warranted.  Below is the radiographs and venograms from the second visit 5 days later.  I will also post a normal venogram for comparison.

NORMAL VENOGRAM FOR COMPARISON TO LOBO'S

We were unable to perform suggested derotation and tenotomy as financial constraints did exist.  Owner opted to give Lobo more time as he was laying down which is protecting the vital blood supply.  Contact was  made with owner approximately 6 weeks after second visit and Lobo was not improving and he was ready to euthanize and I offered to take Lobo to further his treatment and if not able to be successful I would humanely euthanize if needed.  Lobo was transported to IEPVS and new radiographs and venograms performed.  Notable hoof wall growth had occured and was surprisingly very close to even from toe to heel.  Moderate improvement in venograms in areas of the coronary band, face of p3 and tip of p3.  Considerable displacement of the circumflex still exist and very severe compression of vascular bed under apex of p3 is still present.  Note the changes in the soft tissue parameters on the lateral films.  Note the lucent zone that indicates the level of separation of the horn/lamellar zone.  Despite improvement of venogram, more mechanical release in the area of the circumflex  and solar vascular bed is need and derotational shoeing and tenotomy was performed.  Note the red line is the trim line and guide for shoe placement.  The shoe is a 5 degree rail shoe with a trailer welded in to prevent the toe from tipping up after DDF tenotomy.  The shoe is placed at zero palmar angle with a minimum of 20 mm space below p3 and the 5 degree helps prevent painful subluxation of the coffin joint.  This shoe is atraumatically applied with adhesive and nylon strips.  Two part silicon rubber is used to prop shoe up and apply caudal solar weight distribution.

POST TENOTOMY RADIOGRAPH

TENOTOMY RAIL SHOE, POST TENOTOMY RADIOGRAPH

Lobo has went from laying down 90 percent of the time to standing 90 percent of the time.  Attitude and appetite have greatly improved.  The plan is to recheck venogram and lateral radiographs in 2-3 weeks after tenotomy.  I will gladly post those so we can all learn from this case.  With the amount of bone remodeling that has already occurred to the fragile thin rim of coffin bone it is less likely we will have as good of a response as we would have if derotational shoeing and tenotomy where performed in the important window of opportunity at the second visit.  However, I do expect a great improvement in the hoof growth and patient comfort.  The amount of bone resorption will be what prevents Lobo from returning to a previous level of perfomance.  We will have to wait and see.

I would like to thank my Lovely wife for helping and enduring the  many crippled horses I drag to home to try to fix and learn from.  It is vital to my education to have cases like this. I would also like to thank Brendan Frost for donating a Sunday afternoon to help me shoe Lobo.

Stay tuned for more exciting podiatry cases!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!