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


Swelling on Outside of Carpus (Knee)


A bubble of swelling of the upper lateral carpus is usually swelling of the carpal canal, which is the structure through which the all-important flexor tendons run as they traverse the carpus.

This swelling may be seen in an otherwise sound horse, but could also be indicative of disease or injury. Of course, direct traumatic injury can cause generalized swelling (that is not as well-defined) in this area.

  • Code Orange

    Call Your Vet at Their First Available Office Hours
    • If you notice lameness in addition to this sign.
  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • Even if the horse does not appear to be lame to you.

your role


What To Do

Assess your horse carefully for lameness, noting that this swelling may be a possible cause. Feel the area. Do you notice heat here or pain to pressure? Flex the carpus to assess range of motion. Determine if the horse's range of motion in the affected limb is the same as in the opposite limb, and whether flexion causes a pain response. Share your findings and concerns with your vet.

your vet's role

Your vet will assess the area and may perform a lameness exam to determine whether lameness accompanies this observation. Ultrasound and radiography are the most common imaging modalities used to assess this area.
Questions Your Vet Might Ask:
  • How old is the horse?
  • When did you first notice this problem?
  • Do you notice any lameness?
  • What type of riding is the horse used for?
  • What are the results of the Whole Horse Exam (WHE)?

Diagnoses Your Vet May Consider

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

Very Common
Less Common
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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
more treatments

Author: Doug Thal DVM Dipl. ABVP