By Dr. Becker
Aspiration pneumonia, also called inhalation pneumonia, is a condition of inflamed and infected lungs caused by inhaling (aspirating) substances, including vomit, food, foreign bodies, and regurgitated gastric acid.
The severity of the condition depends on what material has been inhaled, what bacteria are present, and the distribution of the aspirated material into the lungs.
This condition is more common in dogs than kitties. Newborn puppies have a higher risk of aspiration pneumonia, especially if they're bottle-fed or have a cleft palate. Dogs that must be forced-fed are also at a higher risk.
Causes of Aspiration Pneumonia
Aspiration pneumonia can result from disorders that adversely affect an animal's respiratory system or increase the risk of aspiration, including any disease of the pharynx or larynx (which is the back of the throat), esophagus, stomach, or intestines.
These diseases can include laryngeal paralysis, gastroesophageal reflux (also called GERD), megaesophagus, tumors, paralysis of the complex swallowing mechanism, esophagitis (a fancy name for inflammation of the esophagus), pyloric outlet absorption, or trauma. Pyloric outlet absorption means the stomach can't empty appropriately.
It's not the act of vomiting that directly causes aspiration pneumonia. It's the bringing up of contents from the tummy that are then inhaled. Inhalation of anything regurgitated can cause problems.
Induction of general anesthesia is also a trigger for this type of pneumonia. Normally, the placement of a tracheal tube prevents aspiration pneumonia. But sometimes pets can reflux before or after the tube is in place. And sadly, some veterinarians perform surgery without tracheal tubes, which dramatically increases the risks.
Other triggers can be inhalation of smoke, mineral oil, kerosene, gasoline, or any other caustic chemical. Disorders that cause a state of altered consciousness such as seizure disorders can also increase the likelihood. Chronic vomiting can also put a dog at a higher risk of developing aspiration pneumonia.
Believe it or not, a quite common cause of aspiration pneumonia is faulty administration of liquid medication either administered by drench (drench is when a stomach tube is passed down the back of the throat), or by a dose syringe. Any liquid that's given via syringe, whether medication or food, must not be given any faster than the animal can swallow, or the risk of aspiration pneumonia becomes very real.
Symptoms of Aspiration Pneumonia
Symptoms of aspiration pneumonia include difficulty breathing, difficulty swallowing, coughing, fever, runny nose, rapid breathing, an increased heart rate, exercise intolerance, vomiting, regurgitation, loss of appetite and lethargy.
Diagnosis and Treatment
Diagnosis of aspiration pneumonia is made through a thorough physical examination by a veterinarian. Your vet will do abdominal palpation, chest X-rays, a complete blood count, as well as a complete chemistry profile.
Fluid may be removed from the lungs to check for the presence of bacteria through culture and sensitivity testing, as well as cytology.
Aspiration pneumonia is a life-threatening condition, and may require several days or more in an intensive care setting. If possible, airway suctioning should be performed immediately following the inhalation of foreign matter. If the animal is in respiratory distress, oxygen will be given. If there's dehydration or shock present, those symptoms will be treated with an IV drip.
Until a diagnosis is made, the pet should not be given anything orally, especially in acute cases of aspiration pneumonia. Rest will be required, oftentimes cage rest, in a very quiet, stress-free environment -- but it's important that the dog or cat be supervised.
A pet with aspiration pneumonia should not lay on his side for more than about two hours at a time.
If recovery is slow, as in the case of paralysis of the esophagus, continued medical care may be needed for up to several weeks. Once the dog is stable, mild exercise can stimulate expectoration or coughing to help clear the airways. Any underlying cause for the aspiration should be identified and resolved, if possible.
Unfortunately, a pet who has suffered from aspiration pneumonia has a poor prognosis, even with treatment. So it's imperative to focus on preventing the problem from ever happening, and seeing a veterinarian immediately if you feel your pet may have aspirated something.