Aspiration Due to Pneumonia in Dogs
CASE STUDY: Nina’s problems with her esophagus
Nina is a 10 year old female spayed Cocker Spaniel was presented to our Toronto Veterinary Emergency Clinic for acute onset of regurgitating and trouble breathing.
Nina had been previously healthy but the week prior to presentation to our veterinary emergency clinic she had started coughing more. She was presented to her primary care veterinarian that noticed she was having trouble breathing and had a fever. She was referred to the Central Toronto Veterinary Emergency Clinic for further evaluation.
On presentation she was quiet and was breathing very fast and had a fever. During the examination she had multiple coughing fits. When I listened to her lungs she had sounds consistent with pneumonia. She was admitted to the hospital and treated with intravenous fluids and oxygen therapy. After a few hours she was more stable and breathing better. X-rays of her chest were performed that revealed that she had pneumonia and a marked dilation of her esophagus consistent with the disease known as megaesophagus.
The esophagus is a tube that connects the mouth with the stomach. The muscles of the esophagus move the swallowed food and water to the stomach by using a squeezing movement behind the food known as peristalsis. After swallowing, the normal esophagus is emptied within seconds. The opening of the esophagus is in the back of the mouth known as the pharynx, and sits next to opening of the windpipe known as the trachea.
Megaesophagus is a condition characterized by decreased or absent esophageal motility that results in a diffuse dilation of the esophagus. This condition occurs as either a congenital disorder or more commonly as an acquired disorder in adult dogs. Acquired megaesophagus can be secondary to a variety of diseases or most commonly as a primary disorder which the cause is unknown “idiopathic” megaesophagus.
Idiopathic megaesophagus can occur in any breed and typically occurs in dogs between 5 and 12 years. Dogs with idiopathic megaesophagus usually present for regurgitation. Regurgitation is different from vomiting in that it is a passive event that does not involve the retching or abdominal contractions that are commonly associated with vomiting. Regurgitation may occur immediately after eating or many hours later. Dogs with this problem may lose weight, depending upon how much food ultimately reaches the stomach. Other clinical signs include excessive drooling, bad breath and less commonly vomiting. As the food, water, and saliva accumulate in the esophagus there is an increased chance that some can enter into the trachea and lungs causing a serious infection, known as aspiration pneumonia. Signs of aspiration can include a cough, labored breathing, nasal discharge and/or fever. Aspiration pneumonia can develop and the owner may never witness a regurgitation episode. Aspiration of food or water can unfortunately occur at anytime, even if the dog has not been regurgitating for the last several weeks or months.
In idiopathic megaesophagus the physical examination is typically normal but weight loss will likely be detected. Trouble breathing, coughing, nasal discharge, and lung sounds consistent with pneumonia are all things that can be detected on the physical exam.
Idiopathic megaesophagus is made only after secondary causes have been eliminated. An underlying cause is found in only 15% to 25% of adult dogs. Most cases of megaesophagus are evident on x-rays of the chest. Contrast dyes can be used to outline the esophagus and confirm the presence of a megaesophagus.
Treatment for idiopathic megaesophagus is symptomatic in nature, as no treatment has proven to reverse the dilation of the esophagus. Specialized feeding practices are the main stay of therapy. It is recommended that feeding be from an elevated position where the upper body and forelimbs are elevated at least 45 ̊ relative to the hind limbs. The dog should remain in this position for 5 to 10 minutes after eating. There is no consensus on the optimal food to be fed or consistency. Gruels are often fed in the hope that they will “slide” down the esophagus easier; however, some pets tolerate dry food or canned foods in “meat-balls” better than gruels. My recommendation is to offer a low-fat, high-protein diets as they are documented to physiologically increase lower esophageal tone and decrease gastric emptying time. A Bailey Chair, named for the inventor’s dog, is useful in encouraging appropriate and successful feeding technique. This picture is of a Bailey-like chair made by Nina’s owner which she sits in for after she eats.
Feeding multiple small meals a day meal help minimize accumulation in the esophagus. Daily caloric intake should be calculated for dogs based on their ideal weight and patients should be weighed every 2 weeks to document any signs of failure to gain weight. Owners should be counseled at the time of diagnosis about the potential need long term for endoscopically placed gastrotomy tubes. These tubes are easily placed and provide good quality of life for many dogs with megaesophagus. Idiopathic megaesophagus is irreversible, and improvement of the patient’s condition is solely based on its ability to tolerate supportive feeding practices. Weight gain may not occur for several months.
In cases of idiopathic megaesophagus, weight gain, tolerance of oral feeding, and avoidance of aspiration pneumonia are favorable short-term signs. Recurrent bouts of aspiration pneumonia typically influence owners to choose euthanasia. Therefore close monitoring and constant contact with the owner is imperative for successful management.
Owners frequently wonder how long their dogs can live with megaesophagus, and the answer is that as long as they can be kept a good weight and aspiration pneumonia attacks can be controlled, these dogs can live long, normal lives. For example, Bailey, of the Bailey Chair fame, died of lung cancer at almost 13 years of age.
It has been 5 months since Nina was first examined at our Eglinton Veterinary Emergency Clinic and she is doing very well. She has had one further episode of pneumonia but her owners recognized the signs early and she responded well to antibiotics and did not need to be hospitalized. We are so happy to have been able to help Nina and her family.
Posted by: Michael Goldstein, DVM, Diplomate ACVIM
Categorised as: Blog & Articles
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