CANINE BLOAT
Bloat, or Gastric Dilatation-Volvulus (GDV), is a condition affecting primarily large breed dogs. The most commonly affected breeds are Great Danes, Irish Setters, German Shepherds, Afghans, Shar peis and Rhodesian Ridgebacks. “Dilatation” means dilated and filed with gas. This condition progresses to include “volvulus” which means the stomach has twisted on its longitudinal axis. In other words, the stomach fills with air and flips on itself. Once twisted, the blood supply is shut off and gas, food and fluid are trapped in the stomach. They cannot escape past the twist into the intestines or be belched or vomited. The stomach rapidly enlarges, pressing on the diaphragm and causing poor blood flow back to the heart. Heart failure, shock and death can occur within minutes or hours.
Emergency surgery is needed to replace the stomach back into normal position and to fasten it there. If the stomach has lost blood supply for too long it will die despite surgery and the prognosis for recovery is grim. Blood supply to the spleen may also be cut off when the stomach twists and a splenectomy may also be required. Treatment for dehydration, shock, irregular heart rhythm and much post-operative care are required as well. The success rate of surgery is about 50% at a general veterinary hospital and approaches 90% if the pet reaches an emergency veterinary facility that specializes in this sort of surgery and care within an hour or so of the onset of signs. The longer the condition is present the higher the risk of death or serious complications. Surgery and aftercare for this disease can easily run into thousands of dollars.
CAUSES of this condition are really not understood. The tendency is thought to be genetic, as the problem runs in breeds and families of dogs, but the exact mechanism, what actually triggers the condition, is unknown. One theory is that if the dog ate a large amount of dry food followed by ingestion of large amounts of water, the dry food then swells. If the dog exercises strenuously with the stomach this full, the resulting running and jumping causes the heavy stomach to twist from the excessive movement.
The most current theory is that the stomach’s regular contractions during the process of digestion lose their regular rhythm and traps air in the stomach that does not pass on down into the intestine. As the stomach pressure increases, the dog is unable to “belch” off the gas.
SIGNS of bloat include depression, pain, inability to get comfortable, and a protrusion most prominent on the left side of the dog in the area of the stomach. The dog often will lie in the “praying position,” with the front legs drawn fully forward.
RADIOGRAPHS are needed to determine if the stomach has twisted (volvulus).
CAUSES OF CONCERN:
Shock resulting from the distended stomach putting pressure on the large veins of the abdomen obstructing proper return of blood to the heart. This decreases heart output and results in poor blood and oxygen supply.
Stomach wall does not get proper blood circulation due to shock and pressure on the blood vessels from the distention or twisting. If adequate blood flow is not returned quickly to the stomach wall, the stomach wall begins to die and may even rupture.
Spleen blood supply is interrupted if the stomach twists causing a rotation of the spleen and its vessels.
Digestion stops when bloat occurs. That allows the accumulation of toxins in the intestinal tract that activates chemicals causing inflammation. Toxins are also absorbed into the blood circulation.
TREATMENT OF BLOAT:
- Treat shock with IV fluids & “shock” drugs.
- Relieve stomach pressure via stomach tube and/or surgery.
- Return the stomach to its proper position if twisted.
- Remove devitalized stomach wall by surgery.
- Attach stomach to abdominal wall (gastropexy) to prevent recurrence.
- Monitor & treat for heart rhythm abnormalities (arrhythmias) which commonly occur for several days after bloating occurs.
PROGNOSIS. Survival rate depends on severity of distention, amount of time before treatment, and degree of shock present. Approximately 60-70% of dogs will survive when very aggressive therapy is initiated quickly.
