Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Heel Collapse, Negative Palmar Angle Syndrome

Synonyms: Crushed Heel Syndrome, Collapsed Heel, Rolled Under Heels


Collapsed heels are, unfortunately, a common and frequently undetected occurrence in shod horses. There are many misunderstandings about the mechanics of the condition, and likewise lots of unsuccessful treatment.

Wedge pads are often applied to horses with under-run heels, and this tends to worsen the condition because it further crushes the heels. Heel elevation makes the shod hoof look better. It is very important to know that just because the hoof looks better after shoeing, this may not mean that the horse has been helped.

Over time and multiple incorrect trimmings and shoeings, a vicious cycle develops of heel elevation and worsening backward rotation of P3 (pedal bone) with respect to the ground (creating an increasingly negative palmar angle). In a normal horse, the sole surface of the bone has a positive angle. In these horses, that gradually changes. The condition is graded on a scale of 1-4, with 4 being the worst.

Diagnosis involves veterinary lameness and hoof exams. Lateral radiographs are needed to establish the orientation of P3.

Treatment begins with a correct trim, which to begin to normalize the angle of P3 (palmar angle) based on the lateral radiographs.

my vet's role


The prognosis with proper shoeing is fair to good. The more severe grades take months to years to correct.

my role


I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
more observations

Questions To Ask Your Vet:
  • Have you dealt with the collapsed heel syndrome before?
  • Do you have confidence in this plan to treat it?
  • How are we going to judge whether treatment has been successful?
  • Do you have an experienced farrier that you can work with to treat this case?
  • Do you feel that the angle of P3 needs to be made positive as part of the treatment?

There are clues that this condition is developing. These should not be ignored. Whenever we see heel rolling under and becoming very parallel to the ground, it is very important to have radiographs taken to establish the palmar angle and sole depth at the toe versus the heel. Once this is done, a proper trim can be performed, followed by placement of the appropriate shoe.

Related References:

Floyd, AE. Use of a Grading System to Facilitate Treatment and Prognosis in Horses with Negative Palmar Angle Syndrome (Heel Collapse): 107 Cases. Journal of Equine Veterinary Science: October 2010

Author: Doug Thal DVM Dipl. ABVP