Difficulty Breathing (Dyspnea) in Dogs

Summary

Difficulty breathing (dyspnea) is always cause for concern, so any dog who suddenly exhibits this symptom needs emergency medical care.

Many conditions can cause dyspnea, such as CHF (congestive heart failure), brachycephalic airway syndrome, heatstroke, respiratory infections, and cancer, and a variety of other illnesses and injuries. 

Oxygen therapy or more aggressive ventilatory support are used to provide the oxygen a dyspneic dog needs while undergoing diagnostic tests and treatment for the underlying problem. 

A physical examination, blood work, and x-rays may be sufficient to provide a diagnosis for some dyspneic dogs, but more advanced diagnostic imaging may be necessary for other cases.

Guidelines

Difficulty breathing, or dyspnea, is an extremely concerning symptom in dogs and a dog who becomes dyspneic warrants emergency medical care. Dyspnea can occur in dogs of any age, size, or breed. 

Brachycephalic dogs are more susceptible to dyspnea, due to their short-nosed muzzles, narrow nares (nostrils), and elongated soft palate which make breathing difficult. Some breeds, like the different Cavalier spaniels, are predisposed to heart failure as they age, and dyspnea may be the first obvious symptom. 

Dyspnea is characterized by: 

• Heavy panting for no apparent reason • Restlessness • Stiff stance • Collapse • Excessive drooling

• Blue/purple gums or tongue (cyanosis) • Lethargy

Possible Causes

A healthy, normal dog pants sometimes, but this is not dyspnea. Dyspnea occurs with many medical conditions that interfere with the normal process of breathing such as:

• Congestive heart failure • Heartworm disease • Respiratory diseases or infections • Laryngeal paralysis

• Some types of cancer • Brachycephalic airway syndrome (BAS)  • Heatstroke

Dyspnea may occur as a result of an injury or foreign object (e.g. choking) affecting any part of the dog’s breathing apparatus.  

Any condition that affects the nerves and muscles used for breathing can also lead to dyspnea.  These include types of poisoning, like tick paralysis, neuromuscular disorders, and auto-immune diseases.

Risk Factors

The severity of dyspnea depends on many factors and is relative to the severity of the underlying disease causing it. Since breathing is fundamental to sustaining health, even mild dyspnea is an emergency.

Dogs with chronic conditions that interfere with normal respiration may experience some degree of dyspnea on an ongoing basis as the therapeutic goal may be merely to optimize the dog’s ability to breathe.   

Mild dyspnea can be subtle and difficult to detect, especially if the dog normally makes a lot of noise while breathing, like most brachycephalic dogs.

Testing and Diagnosis

Dogs with severe dyspnea may require stabilization upon arriving at the veterinary hospital. In these cases, oxygen supplementation is prioritized over performing diagnostic testing. 

Testing for the condition causing dyspnea typically includes: 

• Physical exam

• Pulse oximetry: a measure of oxygen present in the blood

• Comprehensive blood work, including a heartworm test

• Chest x-rays

• ECG: a measure of electrical impulses in the heart

  Severe cases of dyspnea may require general anesthesia and placing the dog on a ventilator to provide more aggressive ventilatory support. All cases of dyspnea are treated based on the condition causing the symptoms.

Similar symptoms

Dyspnea may be mistaken for

• Rapid breathing (tachypnea) • Panting due to stress or anxiety • Choking (esophageal obstruction)

Associated Symptoms

Other symptoms often seen with dyspnea include: 

• Exercise intolerance • Coughing • Appetite loss • Decreased activity