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


Straining to Pass Manure (in Adult)


Straining to defecate is a rare finding in an adult horse. It is more common in ponies and miniature horses, and very common in newborn foals.

In newborn foals, the most common diagnosis accounting for this behavior is a manure impaction (see the separate "Newborn Foal, Straining to Pass Manure" record).

When observed in an adult horse, straining to pass manure is usually associated with advanced illness including rectal impactions, chronic diarrhea, urinary tract problems, certain types of abdominal pain (colic), or neurologic problems.

In severe cases, rectal prolapse (lining of the rectum everted out the anus) can result from excessive straining.

  • Code Red

    Call Your Vet Immediately, Even Outside Business Hours
    • If this problem seems severe and has come on suddenly.
    • 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 this seems mild or occasional and the horse seems normal otherwise.
    • 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) and call your vet immediately to discuss your findings and concerns. Recognize that this problem might be associated with a severe or advanced disease process that requires aggressive diagnosis and treatment.

What Not To Do

Do not try to internally examine or pull manure out of your horse's rectum. Do not give an enema to an adult horse that is straining to pass manure. Do not put anything up the horse's rectum. The rectal tissue is fragile and can be easily ruptured, causing life-threatening complications.

your vet's role

Your vet will assess the horse's general health and may recommend additional diagnostics to rule out the common causes for this problem.

In some cases, to prevent rectal prolapse, your vet may recommend the use of medication to stop a horse from straining.
Questions Your Vet Might Ask:
  • How has the horse's general health seemed to you recently?
  • When did you first notice this?
  • Does the horse's behavior seem normal otherwise?
  • Have you changed your horse's feed or management lately?
  • Has the horse been showing signs of abdominal pain (colic)?
  • Does the horse have diarrhea or loose manure?
  • How much manure has the horse passed over the last 24 hours?
  • 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
more diagnoses

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