Noncardiogenic Pulmonary Edema in Dogs
Noncardiogenic edema is caused by an increased permeability (or the ability to pass through, as by osmosis) of the blood vessels of the lungs. This increased permeability results in the leakage of fluid into the lung, causing edema, or swelling. If this becomes severe, the edema may be accompanied by an inflammatory response and an accumulation of inflammatory cells in the lung.
There are several factors which can cause changes in the permeability of the lung’s blood vessels. Dogs that have edema as a result of a brain disorder, from a response to an electric cord bite injury, or from an upper airway obstruction might experience a systemic release of catecholamines (neurotransmitters and hormones). This release would lead to a causative effect, with systemic constriction of blood vessels shunting blood into the lungs and overloading the blood vessels of the lung, damaging them, and leading to inflammation and swelling of the lungs.
Manifestation of a generalized inflammatory response in the lungs develops in patients with a bacterial infection of the blood, or with pancreatitis, and will often worsen over the 24 hours following the initial episode. The most seriously affected patients may progress from apparently normal health to a fatal condition only hours after the incident.
Symptoms and Types
- Difficulty breathing
- Increased breathing rate
- Standing in unusual positions to breathe better
- Pale or bluish gums
- Spitting up pink, frothy saliva, or bubbles of saliva
- Increased rate of heart beat
- Upper airway obstruction
- Paralysis of the larynx
- Choke-chain injury
- Mass in the lung
- Abscess of the lung
- Acute neurologic disease (brain disorders)
- Head trauma
- Prolonged seizures
- Systemic inflammatory response syndrome
- Bacterial infection in the blood
- Inflammation of the pancreas
- Electric cord bite injury
- Smoke inhalation
- Aspiration pneumonia (sucking fluid back into the lungs)
You will need to give a thorough history of your dog's health, onset of symptoms, and possible incidents that might have precipitated this condition. The history you provide may give your veterinarian clues as to which organs are causing secondary symptoms.
He or she will perform a complete physical exam on your dog, including a chemical blood profile, a complete blood count, a urinalysis and an electrolyte panel. Arterial blood gas measurement, and pulse oximetry will also be performed, along with coagulation testing (whether the blood is clotting normally). Radiograph images of the thoracic (chest) cavity are essential for making a definitive diagnosis, and an echocardiogram may also be performed to rule out, or confirm, pulmonary (lung) edema caused by heart disease.
Your dog will be hospitalized if it is experiencing severe respiratory dysfunction. Dogs with moderate to severe disease are given oxygen therapy and cage rest in a quiet environment to minimize stress, since anything that can bring on anxiety may cause the production of stress hormones. Some dogs may be put on a mechanical respirator if they are having too much of a problem breathing on their own.
Living and Management
Often, dogs with noncardiogenic edema will worsen before improving. Severely ill patients have a poor prognosis. However, mild to moderately ill patients stand a good chance of full recovery, and the long-term prognosis is excellent for recovered patients. One of the ways you can prevent noncardiogenic pulmonary edema in your dog is by taking steps to prevent it ffrom chewing on electrical wires. Another way to prevent noncardiogenic pulmonary edema is to get immediate veterinary treatment for your dog at the first sign of seizures or other indications.