Narrowing of a dog's esophagus is not very common, but when it happens it can be troublesome enough to require surgical intervention. There are several potential causes that may trigger a case of narrowing of a dog's esophagus, therefore it's important to see the vet for proper diagnosis and treatment. Many dog owners are not aware of the narrowing until the dog starts exhibiting symptoms. Following is information pertaining the causes and treatment options for the narrowing of a dog's esophagus.
Causes of Narrowing of a Dog's Esophagus
The narrowing of a dog's esophagus, medically known as an esophageal stricture can have several causes. This condition may start slowly and progressively worsen with time. The narrowing occurs as a result of inflammatory processes causing excess production of fibrous connective tissue (scar tissue). Seeing the vet as soon as the narrowing of a dog's esophagus is suspected is important.
Any condition that causes deep damage to the esophagus may evoke narrowing as a secondary result. A common underlying cause for a narrowed esophagus in dogs is damage from stomach acid. This can happen as a result of acid reflux in dogs and in cases of repeated vomiting.
In some cases, the stricture may occur after a dog undergoes a procedure that requires general anesthesia such as following a dental cleaning or spay surgery. The onset of an esophageal stricture after anesthesia in dogs may be the result of the combination of pre-anesthetics and anesthetics (which reduce lower esophageal sphincter pressure), feeding the dog prior to surgery (which encourages stomach contents to seep into the esophagus) and incorrect positioning of the dog on the surgical table (which may prevent drainage of acids).
Sometimes a stricture may form after the esophagus is damaged from ingesting caustic substances. Trauma resulting from presence of a foreign body or ingesting something rough scraping the surface of the esophagus (like a peach pit or stick) is also a possible cause for the narrowing. At times, narrowing of a dog's esophagus occurs as a result of certain medications such as those that require to be given with food to prevent ulceration. Surgical procedures involving the esophagus may too cause a stricture. In some rare cases, strictures are present from birth. It's important to rule out other possible causes of a narrowed esophagus in dog such as presence of tumors.
"About 65 percent of esophageal strictures are attributed to anesthesia. Peristalsis is markedly delayed in anesthetized animals, allowing the acid, which usually is returned rapidly to the stomach, to be in contact with the esophagus for extended periods."~ Robert Runde, VMD, Ronald Lyman DVM
Symptoms of a Narrowed Esophagus in Dogs
The symptoms of a narrowed esophagus in dogs generally start within one to three weeks following the damaging event. If your dog recently underwent anesthesia, it's important keeping an eye for these signs of trouble.
Affected dogs may develop regurgitation shortly after eating. Regurgitation is quite different from vomiting. While vomiting is the expulsion of food from the stomach or small intestine, regurgitation is expulsion of food that didn't have the chance to reach the stomach yet.
When dogs regurgitate, it's often a quite passive action, there is no drooling or lip licking beforehand and you won't see stomach contractions followed by heaving. The food just exits the mouth with little effort involved. Because the food was in the esophagus (the food pipe), it may be shaped like a tube and warm. Many dogs are tempted in re-eating the regurgitated food because it's doesn't contain stomach acids and therefore tastes the same as food.
Because the dog's esophagus is narrowed, affected dogs may have a hard time keeping down solid foods. Liquids may pass through, but solid foods may be regurgitated shortly after ingestion. Some dogs have trouble eating as swallowing can be painful. Medically, painful swallowing is known as dysphagia. As the condition progresses, affected dogs may develop loss of appetite and subsequent weight loss. In some cases, fever, cough and trouble breathing may be indicative of a complication known as aspiration pneumonia.
At the Vet's Office
Your vet will inquire about your dog's medical history and will ask several questions such as when the symptoms first started. Because physical examination doesn't provide much information, several diagnostic tests may need to be carried out. Regular x-rays may not provide much diagnostic information other than the presence of an esophageal foreign body.
The most definitive diagnosis comes from contrast studies using barium mixed with food and an endoscopy of esophagus.
The contrast studies involve having the dog ingest the contrast medium barium mixed with food. The contrast medium, in this case, allows the vet to visualize the food moving along through the food tube and can therefore help detect any narrowing.
Endoscopy involves the insertion of a a flexible tube through the dog's mouth and throat with a light and camera attached to it so that your vet can visualize the walls of the esophagus.
This procedure can also help rule out the presence of a hiatial hernia which takes place when top portion of the dog's stomach herniates into the esophagus, causing a partial obstruction. During the endoscopy, if it warrants it, samples of tissue may be taken so to help rule out any presence of malignant growths.
Treatment for Narrowing of a Dog's Esophagus
There are several treatment options for narrowing of a dog's esophagus. The choice depends on a variety of factors such as the location of the stricture and the amount of scar tissue present.
Unfortunately, surgical removal of the stricture is not very successful (unless there is a malignant mass) because of the way the esophagus is made. This approach has a low success rate and repeated surgeries are often necessary.
Mechanical dilation by buogeniage in an effort of widening the passageway may be an option. In this treatment plan, several dilators (called bougies) are passed through the stricture. Usually, several treatments are needed. The procedure is not without complications such as risks for perforation or the formation of diverticuli.
Another procedure that has attained good results involves the use of balloon catheters. The catheter is passed through the esophagus and then the balloon is inflated to widen the passage. This method offers reduced risks for perforation, but may require repeated attempts at several intervals. Following dilation, in severe cases affected dogs need to be fed through a stomachtube so to bypass the recovering esophagus.
In some cases, endoscopic electrocautery incisions of the stricture may be an option before proceeding to dilatation. Most of these procedures are best done by a board-certified surgeon. Medications to protect the esophagus are often administered so to decrease the chances for ongoing reflux which may trigger inflammation and stricture reformation.
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