Laryngeal Disease in Dogs

Laryngeal disease is the result of hereditary or acquired laryngeal paralysis, the state in which the laryngeal muscles that form your dog’s voice box become weak or paralyzed and the cartilage that those muscles support collapses inward. Laryngeal disease may be congenital or acquired, idiopathic (of unknown cause) or the result of tumors, cancer, or physical trauma.

The Irish Setter, St. Bernard, Newfoundland, Golden Retriever and Labrador Retriever breeds are the most likely to develop acquired laryngeal paralysis, and males are affected at twice the rate of females. The Bouvier de Flandres, Siberian Husky, Bull Terrier, German Shepherd, Rottweiler and Dalmatian breeds are most disposed to have congenital laryngeal paralysis. Congenital paralysis can develop very early in life, beginning around four months of age.

• Noisy respiration
• High pitched sound accompanying air intake
• Panting
• Gasping or respiratory distress
• Reduced activity
• Decreased desire to exercise
• Coughing
• A change in the sound of your dog’s bark (common)

Congenital

Hereditary laryngeal paralysis is a result of a polyneuropathy syndrome, a generalized nerve disorder. Some dogs may be born with laryngeal paralysis, and others will develop the condition within the first year of life.

Acquired

Acquired laryngeal paralysis develops after birth, more commonly in when a dog is middle aged and older. It is most commonly idiopathic, which means that the cause is completely unknown. However, other causes are possible and they include:

• Trauma, such as penetrating wounds, injury as a result of ingesting foreign materials (bones, etc.), or blunt trauma to the neck.
• Cancer originating in or spreading to the larynx, or cancerous tumors located near the larynx that put pressure on or invade the space of the larynx.
• Hormonal deficiencies, such as hypothyroidism or hyperandrenocorticism.
• Immune-related disorders
• Complex nervous system disorders
• Inflammation or infections of the chest cavity
• Diseases with an origination from the chest cavity, this may include chronic infections, inflammation, cancer, or tumors
• Existing lung abnormalities. This may include a history of pneumonia or any airway diseases.
• Fluid build-up in the chest cavity
• Fluid build-up in the lungs

Because the symptoms of laryngeal disease overlap with common problems in aging dogs, cardiopulmonary diseases, bronchitis and symptoms of obesity, it is more difficult to diagnose acquired laryngeal disease in older dogs than congenital laryngeal disease in puppies. Be sure to report your dog’s symptoms along with a full history of their development, including any historical physical trauma, in order to aid swift diagnosis. If you're interacting with a new veterinarian, this will include a thorough breakdown describing any symptoms, incidents, or general health complications that were previously recognized in your dog. It's especially important to recall symptoms that you did not visit the veterinarian for, as these will be undocumented and may only be recognized while not at the veterinarian's office.

The veterinarian will order a complete blood count in order to detect abnormal levels of red and white blood cells as well as platelets and a chemical blood profile in order to measure your dog’s hormone levels. The veterinarian will also conduct a urinalysis in order to measure your dog’s calcium and phosphate levels and urine specific gravity. These tests will determine if your dog has a hormonal deficiency, nervous system disorder, or immune-related disorder that may be causing the laryngeal disease. It will be important to detect aspiration pneumonia, which can be recognized through diagnostic imaging techniques such as X-ray, fluoroscopy, and bronchoscopy.

The veterinarian will conduct a physical examination in order to detect palpable abnormalities in the throat such as a mass or a tumor. Further, a chest radiograph may be taken in order to view the larynx and surrounding areas. Finally, a laryngoscopy may be necessary. This will involve sedating your dog so that your veterinarian may examine the larynx with an endoscope, which is basically a flexible tube with a small light attached that allows the area to be visually examined. The laryngoscopy will help detect masses and allow the veterinarian to view the function of the larynx during respiration.

Treatment of very mild cases of laryngeal disease can include a regular regimen of anti-inflammatory medications, antibiotics, and bronchodilators. Treatment also involves keeping your dog in a cool, well-ventilated environment, avoiding strenuous exercise and avoiding choke collars. If the veterinarian has okayed general exercise by way of walks, a body harness will be suggested in the case of a choke collar.

Treatment of laryngeal disease caused by cancer, hormonal deficiencies, immune or nervous system disorders, and inflammations or infections of the chest cavity will vary but focus on stabilizing the dog and addressing the underlying cause.

However, treatment of severe and congenital laryngeal paralysis typically requires surgery. Depending on the severity of your dog’s condition, they may be treated on an outpatient basis from diagnosis until surgery, or they may require hospitalization. You may want or need to seek a specialist to perform the surgery. While awaiting surgery, oxygen therapy, sedation, steroids, intravenous fluids, and, most extremely, a temporary tracheostomy, or temporary surgical opening into the windpipe, are methods that may be employed to help your dog regain comfort and stability. If your dog is awaiting surgery at home, keep her in a cool, well-ventilated environment, restrict activity and avoid using a collar.

Surgical methods will vary based on the severity of the paralysis, and will be determined based on your veterinarian or specialist’s expertise. The two most common methods are arytenoid lateralization, in which the collapsed cartilage on one side will be tied to the larynx wall, and a permanent tracheostomy, or opening into the windpipe.

Whether or not your dog has had an operation (surgery), you will need to monitor him closely in order to track recovery. Your dog will be at a heightened risk of aspiration pneumonia of the inflammation of lungs and bronchial tubes, as an outcome of a bacterial infection caused by inhaling food or liquid. Symptoms include shortness of breath, wheezing, cough, and "hacking." Contact the veterinarian at the sudden onset of these symptoms to schedule a check-up.

Prognosis is very good in mild cases and after effective surgery. Prognosis in the case of cancer varies. The veterinarian will strongly advise to have your dog neutered or spayed if his laryngeal disease was hereditary in order to eliminate the possibility of breeding.