Noisy Breathing In Dogs

Stertor and Stridor in Dogs

Unusually loud breathing sounds are often the result of air passing through abnormally narrowed passageways, meeting resistance to airflow because of partial blockage of these regions. The origin may be the back of the throat (nasopharynx), the throat (pharynx), the voice box (larynx), or the windpipe (trachea). Abnormal breathing sounds of this type can be heard without using a stethoscope.

Stertor is noisy breathing that occurs during inhalation. It is a low-pitched, snoring type of sound that usually arises from the vibration of fluid, or the vibration of tissue that is relaxed or flabby. It usually arises from airway blockage in the throat (pharynx).

Stridor is high-pitched, noisy breathing. The higher-pitched sounds result when relatively rigid tissues vibrate with the passage of air. It often occurs as the result of partial or complete blockage of the nasal passages or voice box (larynx), or collapse of the upper part of the windpipe (known as cervical tracheal collapse).

The upper respiratory tract or upper airways includes the nose, nasal passages, throat (pharynx), and windpipe (trachea).

Noisy breathing is common in short-nosed, flat-faced (brachycephalic) dog breeds. Inherited paralysis of the voice box, known as laryngeal paralysis, has been identified in Bouviers des Flandres, Siberian huskies, bulldogs, and Dalmatians.

Acquired paralysis of the voice box (laryngeal paralysis) is more common in certain giant-breed dogs, such as St. Bernards and Newfoundlands, and in large-breed dogs, such as Irish setters, Labrador retrievers, and golden retrievers, than other breeds.

Affected short-nosed, flat-faced dogs with inherited paralysis of the voice box typically are younger than one year of age when breathing problems are first detected. Acquired paralysis of the voice box typically occurs in older dogs. Inherited paralysis of the voice box has a 3:1 male-to-female ratio.

Symptoms and Types

• Change or loss of voice – inability to bark
• Partial blockage of the upper airways produces an increase in airway sounds before producing an obvious change in breathing pattern
• Unusually loud breathing sounds may have existed for as long as several years
• Breathing sounds can be heard from a distance without the use of a stethoscope
• Nature of the sounds range from abnormally loud to obvious fluttering to high-pitched squeaking, depending on the degree of airway narrowing
• May note increased breathing effort; breathing often accompanied by obvious body changes (such as extended head and neck and open-mouth breathing)