What is laryngeal paralysis?

Laryngeal paralysis is a condition where the cartilage in the larynx becomes paralysed. There are two forms of this disease: a congenital form commonly seen in Siberian huskies, dalmatians, and bull terriers, and an acquired, geriatric-onset form most frequently found in middle-aged to older large-breed dogs, such as labradors, golden retrievers, German shepherds, kelpies, Australian cattle dogs, setters, and ridgebacks.

How is the larynx affected?

The larynx is a cartilaginous structure in the throat that functions as the opening of the airway. It opens and closes with breathing and also allows a dog to bark. During swallowing, the larynx closes and elevates to prevent food or fluid from entering the airway and lungs.

Acquired laryngeal paralysis occurs as part of a generalized neuromuscular disease, affecting nerves and muscles throughout the body. The fine nerves and muscles of the larynx, throat (pharynx), and oesophagus are typically the first to show signs. Endocrine diseases such as hypothyroidism can also contribute to laryngeal paralysis through a condition known as polymyopathy. This disease is progressive, meaning dysfunction of the larynx and throat worsens over time.

Signs of laryngeal paralysis

The most commonly affected functions are breathing (larynx) and swallowing (pharynx and oesophagus). Early signs include:

• Reduced exercise ability (often mistaken for aging-related fatigue)
• Change in bark
• Increased breathing noise, especially during exertion
• Coughing or spluttering, particularly while drinking or later while eating
• Heat intolerance

Can this be an emergency?

Yes. Although symptoms often progress gradually, some dogs can develop sudden, severe respiratory distress due to over-exertion, overheating, or excitement. If aspiration occurs and food enters the lungs, a dog can experience sudden breathing difficulties.

Diagnosis of laryngeal paralysis

Laryngeal paralysis is often suspected based on breed, history, and clinical signs. A definitive diagnosis is confirmed through an upper airway examination, which requires light anaesthesia. The veterinarian will observe the larynx during respiration, and failure of the arytenoid cartilages to open during inhalation is diagnostic of laryngeal paralysis.

Additional tests

• Chest x-rays: assess lung health and check for pneumonia due to aspiration.
• Blood tests: rule out endocrine diseases such as hypothyroidism.
• CT scan: may be necessary to evaluate for tumours affecting the throat or lungs.
• Fluoroscopy (live x-ray swallowing study): used in some cases to assess swallowing function.

Treatment for laryngeal paralysis

Though laryngeal paralysis is progressive and cannot be cured, lifestyle adjustments and surgical intervention can significantly improve a dog's quality of life.

Lifestyle changes

• Reduce exercise expectations: limit walks to 5 minutes or discontinue them based on condition. Only exercise during cooler times of the day.
• Avoid triggers: prevent over-excitement, over-exertion, or overheating. Anti-anxiety medications may help in unavoidable situations, such as thunderstorms.
• Adjust feeding routine:
  • Feed from an elevated position to aid swallowing.
  • Always supervise meals to monitor for choking.
  • Use slow-feeder bowls or hand-feed to prevent gulping.
  • Avoid sloppy foods like gravy, which are more easily aspirated. Opt for kibble or meatball consistency.

When is surgery recommended?

Surgery is indicated when breathing difficulties significantly impact a dog's ability to perform daily activities. While surgery does not restore normal function, it greatly improves comfort and quality of life.

Surgical procedure: arytenoid lateralization

• A small incision is made in the neck.
• A permanent suture is placed in the laryngeal cartilage to hold it in a partially open position.
• This helps keep the airway open while still allowing the epiglottis to protect against aspiration.
• Typically, only one side is operated on, but in some cases, a second procedure may be required if breathing remains compromised.
• The surgery does not enter the mouth and involves minimal discomfort.
• Your pet will be discharged on the day of surgery as this is a minimally invasive procedure and it is essential to keep stress minimal.

Risks and complications

All anesthetized dogs are at risk for gastric reflux and potential aspiration. Dogs with laryngeal paralysis are at a higher risk due to their compromised airway. Postoperatively, aspiration pneumonia remains a concern, particularly in the first week after surgery. Hospitalization for 24-48 hours post-surgery is recommended for monitoring. Medications are given to reduce the risk of reflux and regurgitation, but the risk cannot be entirely eliminated.

Prognosis

• Without surgery: dogs will experience progressive breathing difficulties, leading to a poor quality of life and eventual euthanasia.
• With surgery: most dogs show significant improvement in breathing and can have up to 12 months of good quality life. However, the disease is progressive, and eventual aspiration pneumonia is likely. While some cases of pneumonia can be treated, it often becomes a life-threatening issue in the long term.

What to expect after surgery

• Hospitalisation: your pet will not stay overnight and will be discharged on the same day as surgery to minimise stress.
• Recovery period: your dog will require a 2-week recovery period post-surgery.
• Close monitoring for regurgitation and vomiting is advised.