Intestinal Displacements and Torsions (Volvulus) in Horses

The gastrointestinal tract of horses is long and convoluted. It is packed into a relatively small space, requiring the structures to bend and fold around each other, making displacement a risk for all horses at any time. The cause of volvulus is commonly unknown. Horses with torsions show sudden, severe colic symptoms that often do not respond to pain medications.

Displacements are characterized by what part of the gastrointestinal tract is affected.

Right dorsal displacement occurs when part of the colon gets wedged between the body wall and the cecum (the pouch between the large and small intestine).

Left dorsal displacement occurs when the colon moves over the spleen and becomes trapped between the spleen and the body wall. These displacements are commonly associated with impactions in the pelvic flexure or accumulation of gas within the colon.

Internal incarcerations occur within the abdomen when a portion of the small intestine pokes through one of the normal anatomical holes within the abdominal structures and becomes trapped.

Inguinal hernias occur in stallions when the intestine drops through the vaginal ring and settles next to the testis and epididymis (the structure that attaches the testicle to the body). Colic signs are usually moderate to severe. Inguinal hernia requires emergency veterinary attention as the horse will deteriorate rapidly.

Displacement and torsions are common in horses. Some types, particularly inguinal hernias, are most commonly seen in specific breeds such as Tennessee Walking Horses, American Saddlebreds, and Standardbreds.

Horses with the symptoms of mild or moderate abdominal pain (colic) require immediate medical attention to determine the underlying cause. Horses with severe colic require emergency veterinary care. Conditions that cut off the circulation to parts of the gastrointestinal tract benefit from early and aggressive surgical treatment. Conditions that do not cut off the blood supply are less urgent and in some cases resolve on their own or are managed with medication.

Displacements occur when part of the large or small intestine gets hooked under, between, or in other organs or structures in the body. For reasons that are often not clear, a loop of intestine moves into an unusual place and is unable to return to its normal position.

A volvulus or torsion is a twist in a tubular structure such as the small or large intestines. The intestines are constantly moving to keep food and other material traveling along the GI tract. Sometimes during these movements, part of the intestine twists. If the intestine twists past a certain point, it pinches itself off in such a way that it can no longer return to normal on its own. Depending on how severe the twist is, the blood supply is compromised and oxygen can no longer reach the tissue inside the twist. The portion of the intestine inside the twist begins to die.

The main symptom of displacements and torsion is abdominal pain (colic). Colic varies in severity.

Horses with mild or moderate abdominal pain require immediate veterinary attention. Horses with severe abdominal pain require emergency veterinary attention.

Diagnostic tools include:

• Physical examination
• Rectal palpation
• Nasogastric intubation (a tube passed through the nose into the stomach to release gas)
• Ultrasound

Intubation of horses should only be performed by a veterinarian. There is no safe way to intubate a horse at home.

Horses often require sedation and pain medication for thorough examination.

Treatment depends on the severity of the condition, the distress of the horse, and whether constricted blood supply is suggested.

Treatments for mild cases include:

• Withholding food to see if the structure will return to normal once it is empty
• Rolling the horse while under anesthetic
• Administering drugs that contract the spleen to release a nephrosplenic entrapment
• Pain medications

In cases where these strategies have failed to produce results, where the condition is severe, or where constricted blood supply is suspected, surgery is necessary. Surgical intervention is often minimal in horses with displacements, and involves repositioning the intestinal tract into the correct location. Horses with compromised blood supplies often require removal of part of the intestine as part of surgical treatment.

Prognosis varies depending on the severity of the displacement or volvulus, whether the blood supply is compromised, and whether surgery is necessary. Cases that recover with medical management have an excellent prognosis. Cases where surgery is performed within 24 to 48 hours of the onset of symptoms have a fair prognosis. Cases where surgery is delayed, especially cases where tissue death has occurred, have a guarded prognosis. Cases where large portions of the intestine are damaged result in euthanasia.

Preventative measures aim to keep the horse healthy and active. Feeding smaller meals many times a day and daily turnout are recommended.

Displacements and volvulus are common in horses.

• Withholding food
• Rolling the horse
• Administering drugs for splenic contraction
• Surgery