Dear Dr. Jody: We have just adopted a seven month old standard poodle. Friends of ours mentioned that their old standard poodle died from “bloat”, and that the breed is predisposed to this condition. What is “bloat” and how to we prevent it from happening to Stella?
Bloat, more correctly known as gastric dilatation and volvulus, or GDV, is a serious lift-threatening emergency in which the stomach becomes distended with gas and twists around on itself, cutting off the blood supply to multiple organs.
Think of a normal healthy digestive tract as a garden hose with a large dilation in the middle of it. One end of the garden hose is the esophagus, delivering food to the stomach from the mouth. The dilation in the garden hose is the stomach, where food is broken down and partially digested. The other end of the garden hose is the intestines, which receive partially digested food from the stomach. Under normal circumstances, things flow smoothly through this garden hose, and all in one carefully coordinated pattern.
In a dog suffering from GDV, the stomach becomes bloated with gas. If the stomach bloats so quickly that the dog is unable to burp to relieve the gas pressure, the distension with gas can cause the stomach to become twisted. Think of our garden hose example, and imagine twisting the hose at either end. As soon as you twist a garden hose, water can no longer pass through. Similarly, a stomach that has flipped over results in a twist at the esophagus and at the intestinal end. This not only prevents gas from being burped up but prevents food from escaping into the intestine. As the normal process of food fermentation continues, more and more gas is produced, but cannot be relieved. Additionally, a twist at either end of the system prevents blood from entering or exiting this organ. The twist can effectively block several major blood vessels and can prevent blood from returning back to the heart.
Because the spleen is intimately associated anatomically with the stomach, it is often involved in the twist. Think of the spleen as an enormous blood-filled sponge with dozens of major blood vessels coming and going. When the spleen twists and blood cannot flow through it back to the heart, the severely compromised cardiovascular system is further enraged.
So now we have a stomach and a spleen that are rapidly dying because blood cannot get into or out of these organs. We have a stomach that is getting larger and larger because the dog cannot burp. We have a very angry heart that is beating faster and faster because the dog is in extreme pain and due to a lack of blood flow. The heart suffers from a potentially fatal arrhythmia called a ventricular premature contraction, or VPC, and the entire cardiovascular system is at risk for collapse from shock.
If the dog does not receive immediate life-saving procedures, he will die within a few hours from this condition. The treatment involves decompression of the stomach, either via placement of a stomach tube or through trocarization (passing an extremely large bore needle through the abdominal wall and into the stomach to let off the gas). Decompression, however, is only one of several necessary steps. The dog must have heart arrhythmias identified via ECG and treated. It may take several days of hospitalization to stabilize the heart. The veterinarian must attempt to resurrect a failing cardiovascular system through aggressive use of IV fluids. And the dog must immediately undergo surgery.
The point of the surgery is twofold: firstly, dead and dying tissues in the stomach and spleen must be identified and removed. If the dog is merely decompressed via stomach tube and not surgically explored, within a few days the parts of the spleen and stomach that suffered compromised blood flow will die and start to decay and the dog will die. Often, the entire spleen requires removal. Secondly, an extremely important surgical procedure, known as a gastropexy, must be undertaken to prevent recurrence of the GDV.
A gastropexy is a brilliantly designed technique whereby a flap of the outer layer of the stomach is elevated, tucked under part of the rib cage, and tacked back down to the stomach. This effectively prevents the stomach from ever twisting over on itself again. Without the gastropexy surgery, about 75% of GDV patients will relapse at some point in their life. It has even been recommended to prophylactically perform a gastropexy in at-risk breeds during their spay or neuter so that they do not experience a GDV when they are older.
Although a GDV can happen in any dog, certain breeds are considered highly predisposed to this horrible condition. These breeds tend to be deep and narrow-chested, and include Great Danes, German Shepherds, Weimaraners, St. Bernards, Doberman Pinschers, and Standard Poodles. It has been reported that as many as 50% of Great Danes will GDV at some point in their lifetime. Owners of such breeds may decrease the risk of bloat by feeding two or more meals per day (as opposed to just one) and avoiding exercise immediately following mealtime.
If your dog displays the classic symptoms of GDV such as a bloated appearance, distress, anxiety, agitation, and frequent unproductive attempts to vomit, please treat this as a potential life-threatening condition and get him to your veterinarian immediately.
With rapid diagnosis and aggressive treatment, many GDV patients recover and go on to live healthy normal lives. Sadly, without such treatment, most patients die rapidly.
No comments:
Post a Comment