Colic in Horses

Key Takeaways

Colic simply refers to pain in the abdomen, and does not provide any specific details regarding what organ system is affected or what underlying condition is occurring. 

• Causes of colic in horses range from mild to life-threatening, and require veterinary assessment

• Symptoms of colic include reduced appetite, reduced fecal production, kicking at the abdomen, rolling, pawing, biting at the flanks, and grinding teeth

• Diagnosis of the underlying cause of colic depends on the history, physical examination, nasogastric intubation, and a rectal examination

• Affected horses are often immediately referred to a specialty hospital if the suspected cause requires surgical intervention

• Most cases of colic are non-surgically managed with pain control, IV fluids, and feed changes

• Horses with medically managed colics have a good prognosis, while horses requiring surgical intervention have a guarded prognosis depending on the severity of their underlying condition

A Closer Look: What is Colic in Horses?

Colic ranges in severity from mild to severe, with more severe symptoms generally having a poorer prognosis. Some horses display signs of severe abdominal pain despite having mild conditions, due to individual pain tolerance levels. Similarly, some stoic horses show few symptoms despite having a severe condition. Emergency veterinary assessment is required for any horse displaying symptoms of colic.

Signs of mild abdominal pain include:

• Reduced appetite • Reduced fecal production • Lethargy • Grinding teeth

• Flehmen response: repeatedly holding the upper lip curled back while inhaling through the mouth 

With moderate abdominal pain, horses show symptoms such as:

• Lying down • Pawing • Biting at their flanks • Groaning • Kicking at the abdomen • Attempts to roll

Signs of horses in severe abdominal pain include:

• Getting up and down frequently • Rolling constantly • Unwilling to stand up • Sweating • Labored breathing

• Aggressively biting or kicking themselves to the point of causing injury

Life-threatening conditions, such as torsions, are most commonly associated with severe abdominal pain. Horses with severe abdominal pain are significantly more likely to require surgical intervention to treat their condition.

Possible Causes

Colic is a nondescript term for any type of abdominal pain. The causes of colic and the affected organ systems range widely. Most causes of colic involve the gastrointestinal system, and include:

• Gastric dilatation • Anterior enteritis • Right dorsal colitis • Gastritis • Strangulating lipomas

• Enteroliths (intestinal stones) • Impaction of the stomach, intestine, or colon • Herniation of intestinal loops

• Parasitic infections of the stomach or intestine • Intussusception, where the intestine telescopes in on itself

• Displacement or torsion of the small intestine or large colon

Other causes of colic affect other organ systems, and include conditions such as:

• Bladder or kidney stones • Bladder infections • Liver disease, such as hepatitis

• Toxicoses, such as red maple toxicity • Reproductive system conditions such as uterine torsion or abortion

Risk Factors

Horses showing signs of colic require emergency veterinary attention to determine the underlying cause and whether surgical intervention is required. It is always best to call a veterinarian as soon as symptoms arise, as receiving care earlier improves the prognosis. At-home treatments must only be provided under veterinary instruction, for both the safety of the horse and to prevent conflict with future treatment protocols. While waiting for the veterinarian, walking the horse to stimulate gut motility and reduce rolling can be helpful and all food must be taken away. Any additional treatment should be delayed until after veterinary evaluation.

Colic is common in horses, with most horses experiencing at least one episode during their lifetime. Some horses have recurrent colic, where they show symptoms of abdominal pain multiple times a year.

Testing and Diagnosis

A veterinarian often begins by administering sedatives and pain medications to reduce stress and discomfort to provide relief and facilitate making a diagnosis. There are three main components to a colic work-up:

• Physical examination • Rectal examination • Nasogastric intubation

The results of these tests help localize the source of the colic and narrow down the list of potential causes. Additional testing may include: 

• Blood work • Urinalysis • Ultrasound of the abdomen • X-rays of the abdomen

• Gastroscopy to examine the stomach • Cystoscopy to examine the bladder

• Abdominocentesis (sampling fluid within the abdomen)

Horses that respond favorably to initial treatments are given oral fluids that may contain laxatives. Repeated administration of pain relief and repeated intubation may be required to keep the horse comfortable. Motility stimulants, antibiotics, or muscle relaxants are also used as needed. Treatment continues until the symptoms resolve. As the horse improves, feed can be slowly reintroduced, while watching closely for relapse of symptoms. 

Horses that do not respond to initial treatment efforts, or “break through” the medication and continue to show signs of severe pain, usually have a life-threatening condition requiring surgical intervention. Approximately 10% of colic cases require surgery, and colic surgery provides both diagnostic and therapeutic benefits. Horses must be transported to a specialized facility with a board-certified surgeon. Most causes of severe colic are treatable with prompt surgical intervention, however the survival rate ranges between 50-80%, making the procedure risky. Performance horses often return to work after about three months of recovery.

Similar symptoms

The discomfort of going into labor can be difficult to distinguish from colic in mares who are near-term. In both cases, monitoring closely allows for prompt intervention.

Associated Symptoms

Depending on the cause of colic, other symptoms that may be seen include:

• Yellow gums (jaundice) • Bright red gums • Pale gums • Diarrhea • Bloody urine

• Uncoordinated gait (ataxia) • Abdominal swelling • Straining to defecate • Difficulty urinating