Cricopharyngeal Myotomy and Myectomy in Dogs

The cricopharyngeus muscle is an esophageal sphincter located at the bottom of the larynx. Its function is to remain closed almost all of time, unless the dog is swallowing food or drink. Problems with the muscle are rare, but can interfere greatly with a dog's life. The animal will be unable to relax the muscle during regular eating, resulting in gagging, retching and in some cases, severe weight loss. 

These cricopharyngeal issues are often termed, “achalasia”. Extreme cases lead to the dog nearing the point of starvation because swallowing is so difficult. The achalasia will first be treated with medication, but if this proves ineffective, surgical intervention may be necessary. As a last resort option, the cricopharyngeal muscle may be sectioned (a myotomy) or a portion of it may be removed (a myectomy). This is performed if the owner does not wish to have a permanent feeding tube placed on the dog's stomach. Only an ACVS board-certified veterinary surgeon should attempt this procedure.

Full blood work including a complete blood count will need to be run on the dog. This will help determine whether it is a good surgical candidate or not. Thoracic x-rays will show the damaged or deformed cricopharyngeus muscle. These x-rays may also reveal if the dog has developed aspiration pneumonia as a result of the achalasia. The operation will be planned based on these images.

The dog will need to fast for several hours prior to surgery. Medication will be administered first to sedate the animal. Then, anesthesia will be applied intravenously. The dog will be intubated and its throat will be clipped and disinfected. An incision can then be made to the throat. A catheter will be placed in the esophagus. The larynx and esophagus will be rotated to expose the cricopharyngeus muscle. At this point, the muscle will either be transected or excised to relax the sphincter. If tissue is removed, it will be sent to a lab to reveal any abnormalities. The throat tissues and skin can then be closed using sutures.

This surgical procedure has extremely varied results. In some instances, a permanent solution is achieved by the myotomy or myectomy. Other dogs experience worse symptoms after the operation. For the surgery to be effective, the muscle must be completely transected, which is difficult to perform. Depending on your personal situation, your vet may recommend inserting a gastronomy tube to treat the dog instead, as it carries less risk.

The dog will need to be monitored as it wakes up from the anesthesia. Hospitalization is generally required for up to three days after the surgery. Pain medication may be administered as soon as the dog regains consciousness. Antibiotics will also be started at this time. The dog will slowly be introduced to food to see if swallowing has improved. Eating will be closely watched in the weeks of recovery to assess if the problem has been treated or not.

A follow-up appointment will be needed to take x-rays of the dog's lungs. This can help identify pneumonia at its earliest stages to treat it before it takes full hold. If tissue has been sent for histopathological examination, the results should be back by this time. If necessary, a treatment plan will be implemented. 

The total cost for a cricopharyngeal myotomy or myectomy can range from $1,000 to $5,000. The cost will be higher if lab work is requested. In some instances, two surgical procedures are needed, which can double the total cost of treatment. Non-invasive options are available, but they can also be costly. The use of antibiotics, antacids, prokinetic drugs and antiemtics for nausea and vomiting can be helpful in treating achalasia. Medical treatment alone may not be enough in some dogs.

Surgery always carries serious but rare risks. Some dogs have very negative reactions to general anesthesia. It also should be noted that a cricopharyngeal myotomy or myectomy may not actually fix the issue that it is treating. In approximately 50% of dogs who underwent this operation, aspiration pneumonia actually worsened after surgery. Hemorrhage during the procedure is also a noted complication. Depending on the dog's age and overall prognosis, this operation may not be deemed worth the risk to the animal. Euthanasia is often the alternative for these dogs.

Certain measures can be taken to prevent achalasia in dogs. Dogs who carry defective genes that result in a malfunctioning cricopharyngeus muscle should not be bred. Always obtain the full medical history of your dog's family when obtaining the animal. This issue is seen more often in younger dogs, so closely monitoring your puppy as it grows may help you identify the problem early. 

Cancer may be prevented by limiting your dog's exposure to dangerous toxins. A high-quality diet free from preservatives can help in this pursuit. Animals have the same negative reactions to second hand smoke that humans do, so eliminating this from your home may improve your dog's health. Trauma may be prevented by always using a leash when taking your dog on walks.