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


Swelling Under Belly or Lower Abdomen


There are a variety of types of swelling found here. A firm doughy like swelling that settles into the lowest part of a horse's belly is called ventral edema. Edema is fluid trapped in the tissue planes. Generally, edema appears in this area due to circulatory obstruction or dysfunction, trauma to an area, inflammation, damaged blood vessels, or loss of blood protein due to a variety of disease processes.

Severe swelling of a limb or sheath or injuries elsewhere on the body can "overflow" or drain down to this area causing edema to develop here. Horses that have had abdominal surgery or have been recently castrated may be expected to have some edema here as healing takes place.

Other than edema, possibilities for swelling in this area include seroma, hernia, abscesses and hematomas.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If the swelling is large, painful or growing rapidly.
    • 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 the results of the Whole Horse Exam (WHE) suggest the horse is otherwise normal.
    • If the swelling is mild or moderate, and not increasing rapidly.
    • If the area does not seem to be painful.
You also might be observing
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your role


What To Do

If you notice that your horse has a swelling on its belly, gently feel it. Generally, edema feels doughy. You can pit it with your finger tips and the impressions you make will stay imprinted for seconds or longer. Fluid, seromas and hernias may feel balloon-like, and abscesses or hematomas can feel like an inflated ball.

Assess your horse using the Whole Horse Exam (WHE), paying particular attention to their attitude and appetite, attitude and appetite and rectal temperature. Assess the swelling, and consider the size, location and feel of the mass. Is the area painful? Share your findings and concerns with your vet.

What Not To Do

Do not ever attempt to lance, open or drain any swelling unless advised to do so by your vet.

your vet's role

Your vet will also feel (palpate) the affected area in an attempt to determine the cause. They will use the horse's history and general physical findings to help understand the nature of the swelling and thus determine an appropriate treatment. Ultrasound is a very useful and frequently used diagnostic for better understanding the nature of soft tissue swelling. In some cases, blood work and other diagnostics may be needed.
Questions Your Vet Might Ask:
  • Can you find other locations of swelling or injury, even distant from the swelling you describe?
  • What is the horse's age, sex, breed and history?
  • Is the horse's attitude and appetite normal?
  • Does pressure on the area seem to cause the horse pain or discomfort?
  • Is the swelling soft and fluidy-feeling or firm?
  • What does the swelling feel like?
  • What are the results of the Whole Horse Exam (WHE)?
  • Did your horse recently undergo abdominal surgery?
  • Was your horse recently castrated?

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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Author: Doug Thal DVM Dipl. ABVP