What you see. The starting point for addressing any equine health related issue is your observation.


Stifle Area Seems Swollen


When I was a very young vet, one of the first mistakes I made was to over-interpret the appearance and feel of the stifle area of a very lame horse. I was convinced that the horse had injured its stifle, when in fact it had a hoof abscess. It was a good lesson for me.

The stifle is a large and complex, high-motion joint surrounded by heavy muscle. In the non weight-bearing horse, the stifle is very hard to assess, even for vets. It can appear swollen when it is not. Compounding this is the fact that many horses resent being touched in this area, so it can be challenging to assess pain to touch.

True swelling of the stifle area can be associated with a variety of underlying problems, from traumatic injury to OCD to infection. The biggest question is always whether or not the swelling is within or outside of the joint, and whether the horse is lame. This determination requires your vet's expertise.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If severe lameness accompanies this sign.
    • If the results of the Whole Horse Exam (WHE) in the resting horse indicate fever (Temp >101F/38.3C) or heart rate greater than 48 BPM.
  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If there is modest or little lameness but significant swelling.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
You also might be observing
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your role


What To Do

Assess the horse's general health using the Whole Horse Exam (WHE), paying particular attention to the feel of the swelling, and the presence of heat or pain. Assess for lameness at the walk and pay attention to the stride length at the walk. Take a photo, trying hard to have the horse bearing weight when you do.

When evaluating an apparently swollen stifle area, always try to get the horse standing squarely behind. If the horse is very lame and will not bear weight on the limb, you cannot assess the stifle area well. You should be cautious of assuming that the area is really swollen. Always compare the look and feel of the apparently abnormal stifle area to the opposite side.

Share your findings and concerns with your vet.

What Not To Do

If a horse is lame and not bearing weight, be very careful of assessing the stifle area. It is commonly (and often incorrectly) interpreted as swollen (or abnormal) in horses that are non-weight bearing.

your vet's role

Your vet will evaluate the limb, and palpate the structures in the stifle area to distinguish normal from abnormal. Joint blocks, radiography and ultrasound are the most common diagnostics that help provide more information.
Questions Your Vet Might Ask:
  • Has there been a traumatic incident that you know of?
  • Is the horse limping or lame?
  • When did you first notice the swelling?
  • How does this stifle compare to the other stifle?
  • If the horse is lame, how lame?
  • Do you notice other signs of disease or injury?
  • Is there a wound in the area?
  • What is the age and breed of the horse?
  • What does the horse do for a living?

Diagnoses Your Vet May Consider

The cause of the problem. These are conditions or ailments that are the cause of the observations you make.

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Treatments Your Vet May Recommend

A way to resolve the condition or diagnosis. Resolving the underlying cause or treating the signs of disease (symptomatic treatment)

Very Common
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Author: Doug Thal DVM Dipl. ABVP