Conditions or ailments that are the cause of a problem that you see - your observation.

Your vet may diagnose

Small Intestinal Strangulation, Strangulation by a Pedunculated Lipoma


The equine small intestine is 50-70 feet long and connects the stomach to the cecum, which is the first part of the large intestine. In healthy horses, the small intestinal lining secretes a massive amount of electrolyte-rich fluid that aids digestion. This fluid mixes with feed material, aids in digestion, and much of it is normally taken back up again by the large colon and cecum downstream.

A common cause of small intestinal strangulation (in middle-aged and older horses) is "strangulating lipoma" aka "pedunculated lipoma". Lipomas are benign fatty growths attached to the mesentery (the sheet of tissue that supports the intestine). Lipomas are often attached to the mesentery by a rope-like stalk (the word "pedunculated" means "on a stalk"). Mesenteric lipomas may sit quietly for years, but one day one somehow becomes looped over and tightens on a segment of intestine- think of a tether ball. The trapped intestine becomes choked off, rapidly fills with blood and fluid, loses its blood supply and within hours, turns purple-black and dies.

DIAGNOSIS- The thickened, fluid filled loops of intestine are detectable on a thorough veterinary exam, usually by rectal exam and/or ultrasound. Belly tap- the sampling of peritoneal fluid is an important test too, as the fluid reflects the damaged small intestine. Usually it is what is reddish from blood seeping into it from the damaged intestine, and the protein is high.

Prompt diagnosis and a decision about surgical intervention is required.

This condition is much more common in older horses- those at least 17 years of age. Horses that are overweight (and insulin resistant horses) may also have a higher incidence of strangulation by a lipoma. When I see an older, especially an overweight horse, with an obvious small intestinal blockage, I always think of lipoma first.

TREATMENT is almost always surgical. Sometimes if the intestine is released (by cutting the stalk at surgery) early in the disease course, the strangled intestine might still be alive and can be salvaged. More often, the intestine has been irreparably damaged. Dead or severely damaged intestine (sometimes up to 50% of the total small intestine length, or more than 30 feet) must be removed (resection) and reattached (anastamosis).

Recovery after these major small intestinal resections can be difficult. These operations are among the most challenging and expensive abdominal operations that equine surgeons perform.

my vet's role


Diagnostics Used

These are tests that might be helpful to make this diagnosis or further characterize the condition.

Very Common
Less Common
more diagnostics


This condition is much more common in older horses- those at least 17 years of age. Horses that are overweight (and insulin resistant horses) may also have a higher incidence of strangulation by a lipoma. When vets see an older (especially an overweight) horse with an obvious small intestinal blockage, we always think of lipoma first.

Many questions cannot be answered until the abdomen is opened and examined.
The prognosis for these cases depends most on how rapidly the condition is diagnosed and the surgery performed. It also depends on how much intestine is involved and/or removed, the general health of the horse, the degree of shock at the time the operation takes place, and the quality of the surgery performed.

If the affected segment is far downstream, it may not be possible to take it out and reattach it end to end, and in that case it must be reattached to the cecum. In my experience, these horses have not done as well. Some surgeons have perfected this technique and have pretty good results.

my role


I might observe

You might make these observations when a horse has this condition.

Very Common
Less Common
more observations

Questions To Ask Your Vet:
  • Why do you think the horse has a small intestinal strangulation?
  • With surgery, what is the prognosis?
  • How sure are you about the diagnosis?
  • Are there other diagnostics that would make you more certain?
  • What is the cost of surgery?
  • What is the likelihood of recurrence after a successful surgery?

All factors that reduce colic in general should help reduce the likelihood of intestinal accident but there are still no guarantees. There are questions about whether obesity contributes to the formation of pedunculated lipoma. Certainly genetics does play a role.

further reading & resources

Author: Doug Thal DVM Dipl. ABVP