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


Flanks Sunken, Drawn Up


A horse with a sunken or shrunken flank or belly is known by horse people as being "drawn up".

Normal healthy horses maintain a balance of water movement between intestinal contents and the bloodstream, depending upon their hydration. A huge large colon full of heavy, wet feed material is what provides much of the contour of the normal horse's lower abdomen and flank. If that wet feed material dries out and shrinks, then the abdomen appears drawn up.

The intestinal contents are in intimate contact with the bloodstream. The colon is intimately involved in the horse's water balance. Imagine the wet-hay sludge content of the 20 gallon intestine coming into contact with a drier than normal "sponge", which is the blood within the vessels of the circulation.

Water flows out of the wet colon contents back into the drier circulation. This dehydrates the mass of sludge in the colon. The result of dehydration then is shrinkage of this mass and a drawn-up appearance. In a healthy horse, there is some fluctuation in the fullness of the flank from this process. After intense exercise,and the associated water and electrolyte loss from sweat, horses will naturally be somewhat drawn up.

  • Code Yellow

    Contact Your Vet at Your Convenience for an Appointment
    • If you consider this a chronic and relatively mild problem that is not changing rapidly.
    • If the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.

your role


What To Do

Assess your horse's general health using the Whole Horse Exam (WHE), paying particular attention to appetite and attitude. Provide free choice water, salt and light hay feeding.

If your horse continues to appear drawn up after rest and water, or shows other problems, especially signs of abdominal pain (colic), depression or loss of appetite, then you should call your vet immediately to discuss your findings and concerns.

your vet's role

Your vet interprets this finding as an indication of dehydration, and looks for other problems or conditions that might be causing it.
Questions Your Vet Might Ask:
  • What are the results of the Whole Horse Exam (WHE)?
  • How is your horse's attitude and appetite?
  • Is the horse drinking water normally?
  • What is the horse's age, sex, breed and history?
  • Has the horse been exercised recently?
  • Does the horse have constant access to fresh water?
  • Has the water source changed recently?

Author: Doug Thal DVM Dipl. ABVP