Dog stridor refers to wheezing noises that are made when a dog breathes (called stridulous breathing).The noise is due to restricted air flow due to some type of problem that typically resides at the dog's larynx, such as a lesion. Wheezing needs to be differentiated from similar respiratory symptoms such as shortness of breath (dyspnea) or difficulty breathing when not standing up (orthopnea). A narrowing of the air passage through the larynx results in obstructed or partially blocked airflow, such as a narrowing of the air passage. The obstruction results in a soft wheezing sound or louder sound which is referred to as stridor.
A veterinarian will be able to hear any wheezing by listening to the dog breathe. The veterinarian will want to sedate the dog in order to conduct a thorough visual exam. Dogs that are having trouble breathing need to be closely observed when sedated. In some cases, emergency resuscitation is needed due to the combination of sedation and breathing difficulty. An endotracheal tube can be inserted to assist with breathing (it needs to be removed in order to examine the nasal cavity).
Problems such as canine laryngitis (laryngeal mucosa) results in coughing, not a change in vocal ability.
Causes and Treatment
Canine Laryngeal Paralysis
Older and middle age dogs, and large breeds commonly are suffering from laryngeal paralysis. Other symptoms associated with canine laryngeal paralysis are a reluctance to exercise and collapse when a dog is exercising itself. Younger dogs suffering from laryngeal paralysis usually have the condition as a congenital disorder (breeds include bull terriers, Siberian Husky, Rottweiler and Dalmatians). Other causes include neorgenic, neuromuscular, or muscular disorders.
Diagnosis involves sedation followed by a technique called electromyography is used to confirm the diagnosis. Paralysis can be partial or complete. In some dogs the disease gets worse over time (progressive). Surgery is used to treat the condition.
Dog Nasal Tumors (Neoplasia or laryngeal tumor)
If a tumor or growth is found, then a veterinarian will take a sample (fine needle aspiration) of the neoplasm or lesion for further testing. Lab tests will indicate if the tumor is malignant (cancer) or benign (slow growing/not cancer.) The condition is rare in dogs.
Congenital Laryngeal Hypoplasia
This is a condition in bulldogs or dogs with similarly shaped heads. The structure of the nose results in narrowed air passages. This narrowing causes an airflow obstruction and sounds such as wheezing or louder sounds. In this case surgical correction is needed.
Accidental injury to the larynx can be life threatening in cases where it obstructs the ability to breathe. Diagnosis is difficult before the trauma is healed. It is also possible for a dog to recover with no treatment (and any breathing assistance that is required). If the mucosa, the pink tissue that covers the thin tubular bones leading from the nose that carry air, then it will need to be surgically repaired.
SNEEZING & NASAL DISCHARGE
Richard B. Ford, DVM, MS, DACVIM and DACVPM
College of Veterinary Medicine
North Carolina State University, Raleigh, NC
LARYNX: COUGHING, DYSPNEA, STRIDOR, SURGERY
Anjop J. Venker-van Haagen, DVM, PhD, DECVS
Stationsstraat 142, 3511 EJ Utrecht, The Netherlands.