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5/29/08

Tribute to Prince Xerxes Photo A Day #2




Megaesophagus~ the condition that took our adorable Zirky from us.  WE LOVE YOU XERXES!

What is Megaesophagus?

The esophagus is the tube connecting the throat to the stomach.  When food is perceived in the esophagus, neurologic reflex causing muscle contraction and relaxation lead to rapid transport of the food into the stomach, like an elevator going down. Other reflexes prevent breathing during this swallowing process to protect the lungs from aspiration.

When these reflexes are interrupted such as by disease in the esophageal tissue or nerve disease, the esophagus loses its ability to transport food.  Instead the esophagus loses all tone and dilates.  Also, the reflex protecting the lung is disrupted and aspiration pneumonia commonly follows.

Anyone who has dealt with a megaesophagus puppy knows what a heartbreaking disease it is.

      In the 2001 Rhodesian Ridgeback Health Survey, megaesophagus was ranked first among reported gastrointestinal disorders, with an 81 percent mortality rate. This disorder occurs in many lines, and though the mode of inheritance is not clearly understood, it is likely a genetic defect.

      While megaesophagus can occur in adult dogs secondary to diseases such as myasthenia gravis, Ridgeback breeders will most commonly encounter it in young pups as they are weaned to solid food, at 4 weeks or thereafter. This congenital form of megaesophagus is characterized by a lack of muscular contractions in the esophagus, which creates a pouch effect in the pup’s chest. Food cannot enter the stomach normally, but instead simply sits in the dilated esophagus, which cannot push the food into the stomach. Because there is no way to restore elasticity to the esophagus by surgical means, there is no course of treatment for this form of megaesophagus.


However, most situations involve management, rather than cure. The difficulties that megaesophagus imposes upon the body are serious and sometimes life-threatening. 
          Because nutrients cannot easily reach the stomach for processing and digestion, malnutrition can become a significant problem. Many cases can be improved dramatically by simply changing the angle of the dog's body during and after eating, and by feeding a diet that is soft and easily transported. Even young puppies can be taught to eat with their front paws on a step-stool and to stay in that position for 20 minutes following feeding. For those that have difficulty with this, creative companies and individuals have fashioned upper-body slings to maintain the recommended position for an adequate length of time. This feeding regimen helps many dogs maintain their caloric and fluid intake. A potentially more severe complication of megaesophagus is aspiration pneumonia. Even with impeccable management, this is a serious risk. The pooling of liquids from saliva or water drinking, along with unavoidable small quantities of food and a host of nasty bacteria, cause a constant situation where fluid is "sloshing" around in the esophagus, ready to flow forward whenever the dog lowers his head. If the dog breathes in at the wrong time, it is extremely easy to aspirate this fluid into the lungs, causing pneumonia. Almost ALL cases of megaesophagus get pneumonia at   some time or another, sometimes many times. Treatment for the pneumonia is broad-spectrum antibiotic therapy, sometimes for prolonged periods. Other than early euthanasia because of management difficulties, intractable aspiration pneumonia is the most common reason for euthanasia in megaesophagus cases. 

2 comments:

becky ward said...

oh, what a sad thing! sorry about your loss. he was so ADORABLE...it almost made me want a dog.

Elena said...

OH No!! THat is so sad. I'm so sorry. It's so awful to lose a pet. Poor little puppy and poor Crossleys.