Anyone have experience with these two issues and specifically how to tell the two apart? I have an extremely large 3 year old warmblood gelding who in the spring of his 3 year old year started to move a little strangely in the walk. When walking he picks his right hind up slightly higher than the other (we are not talking WAY high like in a classic stringhalt case). Noticeable only in the walk. Trot and canter are fine. I had a top lameness vet examine who advised me that he had a catching stifle and that he is so large, give him more time to grow and we would reassess in the fall. Now it’s the fall and the higher stepping motion is slightly worse, although still not exaggerated “belly kicking” type motion. Again noticeable only at the walk. Vet is now thinking stringhalt. However he does not have any of the other classic string halt/neuro symptoms. I can pick his hind feet out normally. He has no issues with backing or turning. Neuro tests are all normal EXCEPT the one where the vet pulls his tail sideways when walking. He does show weakness there, which vet said could indicate either a neuro problem or catching stifles. Does anyone know if there is any way to tell these two issues apart from each other? Vet has advised some light work as if it is UFP, strengthening it may help. Stifle xrays are normal.
Do you have a video?
The two are usually fairly easy to tell apart if you understand biomechanics.
in stringhalt, usually, there is dramatic upward flexion of the hind limb during the adduction phase of limb movement (when the limb is brought towards the body.) The entire limb flexes abnormally (as opposed ot UFP, which is just the stifle.) This usually occurs at the walk, sometimes at the trot, and almost never at the canter. Stringhalt can have a toxicity component - meaning if the horse ate something in the paddock that caused the condition (and the symptoms will cease to persist once plant is removed/horse is treated).
In upper fixation of the patella, in moderate+ cases it is usually obvious in all three gaits, and it is when the stifle “locks” or “catches” - sometimes the leg cannot be brought back under itself - either it is delayed release, and the limb hangs out behind the horse, or it “skips” right before loading phase and looks as if the leg just comes “out” from under the horse. UFP can have a neuro component, sometimes seen with cervical arthritis, usually more often seen with bad shoeing angles (especially behind), stifle injury, or when the horse goes through a sudden growth spurt.
Why isn’t shivers on the roster of suspects? Shivers is neurological and horses with shivers can fail the tail-pull. It is commonly seen in large horses (17+) and in my experience usually diagnosed in warmbloods; though I have seen some TBs with it as well. Symptoms run the gamut from gait abnormality, difficulty holding up hinds, loss of condition, atrophy on one side, neurological deficit in turning/backing up. Best treatment cases I’ve seen include high doses of Vit E, PSSM-type diet, and 24/7 turnout - the important part seems to be finding a farrier tolerant of this condition which – you would be surprised – is very hard.
