...and on the eighth day God created the horse in perfect image, to romp, graze, gallop, play and make manure wherever it darn well pleases, in divine grace.

The Peritoneum is a serous membrane lining the walls of the abdominal and pelvic cavities and surrounding the internal organs. Peritonitis is an inflammation of the Peritoneum that can be local or general, acute or chronic. It can be caused by microbial or chemical agents and it is accompanied by abdominal pain. (1)

The three major causes of Peritonitits are: 1: Systemic disease, 2: penetration of the abdominal wall, and 3: escape of material through the gastrointestinal wall.

Diseases such as influenza, viral arteritis, strangles, and African horse sickness, ( a virus contracted near swampy areas.)

The escape of material through the gastrointestinal wall is caused by breeding accidents, ruptures, parasite damage, rough use of an enema tube or inexpert palpation. (2)

Penetration of the abdominal wall is the most frequent cause of Peritonitis and results from faulty surgical techniques or accidents such as landing on fences or obstacles while jumping.

Primary Peritonitis results from the multiplication of bacteria, fluid and gas collection within the Peritoneal Sac, toxin absorption, abdominal adhesions, or the growing together by scar tissue formations or “structures” within the abdominal cavity that should be separate from one another. It is also caused by intestinal obstruction. (3)

Symptoms of Peritonitis are contractions of the abdomen, severe abdominal pain, elevated temperature, low blood pressure, depression, low pulse rate, constipation, and congested mucous membranes.

The constipation will be followed by large amounts of diarrhea and despite drinking large amounts of water, dehydration. The animal will refuse to lie down and will take on a rigid stance.

There will be loss of appetite and subsequently a loss of condition with possible anemia.

The animal may groan in discomfort and will act restless in its stall. (4)

In mild cases, these signs are less obvious and recovery may come about with little notice. Adhesions will develop.

Severe cases will result death, usually within a few hours or a few days. (5)

A horse showing signs of abdominal pain without any obvious causes should be looked at by a Veterinarian. Peritonitis could be suspected, as it is many times a secondary disease. A physical and laboratory exam will help determine a cause, along with knowledge of a thorough history of the case.

A perforation of the abdomen requires surgery. The Veterinarian can determine whether infection is present, and take steps to treat it. This is usually done with broad-spectrum antibiotics.

It the Peritoneal Cavity has collected large amounts of exudate, it may have to be drained.

If anemia is present, blood transfusions are required. Pain can be treated with tranquilizers or analgesics, (Banamine) for the comfort of the horse and to try to prevent shock.

Peritonitis Colic caused by the inflammation of Peritoneum is due to contamination from perforated lesions in the stomach and intestines, usually caused by stomach worms or bots.

Actual ruptures in the digestive tract can also be a source of inflammation, along with intestinal obstructions. These interfere with normal intestinal movement and prevent normal gut motility. (6)

Prognosis is very poor if rupture occurs, or if twisting or intussusception (telescoping gut, usually in foals) occurs, and death can be imminent.

This article is meant as a guideline and not Veterinary analysis. Always consult a Vet if your horse is experiencing abdominal pain or colic of any type, as these are true emergencies.

Vets have the medical knowledge to differentiate types of colic and abdominal pain, and prognosis and treatment will vary with diagnosis.

Any time a horse stops grazing or eating, goes off feed and has low output of manure, the handler should immediately go on a “Colic Watch.”

Rolling or thrashing, sitting down like a dog, or assuming other unusual positions with all four legs up in the air is not normal horse behavior and the Veterinarian should be consulted post-haste.

Closing with the immortal words of Roy Rogers and Dale Evans, “Happy Trails to You.”

1-6: “Horseman’s Veterinary Encyclopedia,” by Will A. Hadden III, DVM