Colic is a general term given for any abdominal pain. There are many types and causes of colic as well as predisposing factors. A horse’s digestive system is highly sensitive; therefore, colic is a major cause of death in horses.
There are five types of digestive colic: spasmodic, impaction, incarceration, displacement, and excessive fermentation.
Spasmodic colic is the mildest and most common. It is associated with over-excitement or sudden feed changes. It generally responds well to modest medical treatment.
Impaction colic is caused by normal ingesta or foreign material blocking the intestine. It may be caused by increased coarseness of forage, decreased intestinal fluid, or interference with normal intestinal movement. If the blockage prevents passage of gas as well as ingesta, surgical intervention may be necessary.
In incarceration colic, a loop of the intestine may become trapped within a normal or abnormal structure in the abdominal cavity. A common example is a strangulating lipoma. This situation may require surgery if the blood supply to the intestine is cut off.
In displacement colic, a portion of the intestine becomes twisted or caught in an abnormal position. The displacement may or may not be strangulating, but surgery usually is required to save the horse’s life. The picture to the right shows a nephrosplenic entrapment, where the colon (brown) becomes entrapped between the spleen (purple) and the kidney (not visual).
Excessive fermentation occurs when the stomach’s contents ferment more rapidly than they can be eliminated. This usually is caused by eating too much grain. Surgery rarely helps, and medical treatment is difficult. This situation also can cause rapid chemical changes in the blood that lead to abnormal blood flow to the hooves leading to laminitis.
• Irregular feeding times
• Lack of water
• Giving excess water to hot horses or horses deprived of water
• Excess grain
• Moldy feed
• Improperly chewed food due to eating too fast or poor teeth
• Overeating grain when hungry from being off feed
• Consuming foreign objects
• Fecaliths or enteroliths (large accumulations formed in the intestine around foreign material)
• Feeding on the ground where sand can be ingested
• Feeding excessive salt to salt-deprived horses when water is not readily available (rare)
Signs of Colic
• Refusing to eat
• Biting at flanks
• Looking at the abdomen
• An expression of anxiety on its face
• Kicking at belly, rolling, pawing, getting up and down frequently and overall restlessness
• Assuming a saw horse posture (legs stretched out as if to urinate)
• Increased pulse rate
• Normal or raised temperature
• Abdominal distention
• Lack manure production
• Small volumes of firm, mucus-covered feces
There is no easy way to determine whether surgery is needed. A thorough exam and clinical judgment are required. Many times the severity of pain is the deciding factor on whether to go to surgery. Conservative treatment is utilized when possible.
A veterinarian should conduct a physical examination. The initial exam should be done from a distance to better observe the horse’s behavior. The veterinarian will check the heart rate and capillary refill time (checked on the gums) to aid in determining cardiovascular status. He or she also will listen to abdominal noises and perform rectal palpitation to check for irregularities.
Further diagnostic procedures may be required, including blood evaluation, abdomniocentesis, abdominal radiography, endoscopy, ultrasonography, and diagnosis of fecal material.
General Treatment Strategies
Prior to the arrival of the veterinarian:
• Do not allow the horse to eat.
• Prevent injury. Walk the horse if it is trying to roll.
• If the horse is quiet, leave it alone and observe.
• Do not give pain medication prior to the veterinarian’s analysis.
• Medical treatment may include the following procedures depending on the signs exhibited by the horse:
• Nasogastric tube to relieve gas or excess fluid
• Sedation to allow examination
• Analgesic for pain (e.g., Banamine)
• Intravenous fluid to correct electrolyte and acid-base imbalances
• Surgery may involve resection of the damaged intestine
Prevention of Colic
• The following management practices can help you avoid colic in your horses:
• Feed at regular time intervals
• Be sure clean, fresh water always is available
• Provide high-quality feed–high forage, low concentrate.
• Make feed changes gradually.
• Maintain a regular schedule of exercise.
• Provide regular dental care to allow for proper chewing.
• Maintain a regular worming schedule (once every 2 months or as advised by veterinarian).
• Keep foreign materials that could be ingested, such as rubber feeders or fencing material, away from horses.