What is Laryngeal Paralysis?
The opening into the airway in the back of the throat (the larynx) is controlled by two cartilage flaps that open during breathing to allow air to enter and leave the trachea and close during swallowing to keep food and water from entering the airway. Laryngeal muscles are responsible for opening and closing the cartilage flaps.
In laryngeal paralysis, these muscles no long work effectively. The nerves supplying the muscles become damaged, allowing the muscles to relax, which causes the cartilages to collapse inwards. The condition can affect one or both sides of the larynx. The collapse of the cartilages causes partial blockage of the airway, resulting in decreased airflow.
In horses the term “Roarer” refers to horses with a condition called Recurrent Laryngeal Neuropathy (RLN) or Laryngeal Hemiplegia which is similar to the condition seen in dogs. The term “Roarer” is used because of the noise that is often heard by horses with this condition during work or strenuous exercise.
Symptoms of laryngeal paralysis may include:
- Roaring sound during exercise
- Gasping for breath after exercise
- Exercise intolerance
- Heat intolerance
- Voice change
- Excess salivation
- Cyanosis (blue tongue or mucous membranes)
- Syncope (fainting)
What causes laryngeal paralysis?
- In the majority of cases the cause is idiopathic (unknown).
- Immune-mediated disease
- Trauma to the throat or neck, including surgical trauma
- Tumors in the neck or chest area
- Endocrine (hormonal diseases) such as hypothyroidism and Cushing's disease; all dogs diagnosed with laryngeal paralysis should be tested for these diseases and treated if needed.
- Congenital (born with) laryngeal paralysis
Are some breeds more prone to have laryngeal paralysis?
Laryngeal paralysis occurs in large breed dogs more commonly than small breed dogs, and occurs 2-4 times more frequently in males than females.
The most commonly affected breeds for idiopathic (unknown cause) laryngeal paralysis are Irish Setters, Golden Retrievers, Saint Bernards, Newfoundlands, and Labrador Retrievers. However, many of these dogs may develop systemic neurological signs within 12 months or so following diagnosis of laryngeal paralysis. Nerve and muscle analysis of these patients suggest the condition is consistent with a progressive, generalized nerve inflammation. The description “Geriatric-Onset Laryngeal Paralysis Polyneuropathy” or GOLPP has been proposed as a more accurate description of laryngeal paralysis in these dogs.
Nerve inflammation can be controlled naturally using PEA, which is a naturally occurring fatty acid compound found in plants and animals. PEA has natural anti-inflammatory, neuroprotective, and analgesic (pain-killing) properties. Omega 3 fatty acids are also beneficial for healing nerve damage.
The congenital form is seen in Bouvier de Flandres, Siberian Huskies, Bull Terriers, white-coated German Shepherds, and Dalmatians; clinical signs usually occur at an early age in these breeds.
A hereditary predisposition has also been identified in Alaskan malamutes and crosses of this breed.
A laryngeal paralysis-polyneuropathy complex has been identified in Dalmatians, Rottweilers, Leonberger, and Pyrenean mountain dogs.
How is laryngeal paralysis diagnosed?
The best way to diagnose this disease is through direct observation of the larynx with the dog under sedation. Chest radiographs may show aspiration pneumonia which is commonly seen along with this condition.
If laryngeal paralysis is diagnosed the patient should also have blood drawn to check thyroid and adrenal gland function, along with a complete blood count and chemistry panel.
Treatment of laryngeal paralysis
- Do not exercise the dog in hot or humid weather
- Keep stress to a minimum
- Use a harness instead of a collar
- Provide good ventilation or air flow
- Provide calming agents if needed
- Doxepin has been effective in some cases
- Surgical treatment - there are many options - most common complication is aspiration pneumonia
TCVM (Traditional Chinese Veterinary Medicine) Approach to Treatment
From a TCVM standpoint, there are four presentations and different therapies for laryngeal paralysis. Use the tongue color to help determine which presentation fits for your pet.
- Kidney Jing Deficient with local Qi Deficiency - acute onset, adult pure breed dog, tongue pale, swollen or wet - treat using Epimedium Formula along with Qi Performance. Foods to tonify Jing include liver, kidneys, fish, bone, bone marrow, chlorella, spirulina, seaweed, black sesame, ghee, bee pollen, and almonds. Food to promote Qi include eggs, crab, carrots, and turnip. Cold foods to avoid include duck, clams, spinach, broccoli, celery, cucumbers, and watermelon. Massage along the sides of the neck, lower jaw, and thoracic inlet for 3 to 5 minutes daily.
- Wind-Heat Invasion causing Qi/Blood Stagnation and local Qi Deficiency - acute onset, stridor (upper airway noise and distress), tongue red, purple - treat using the herbal formula Pu Ji Xiao Du Yin. Foods to supplement to clear heat include turkey, duck, clams, barley, spinach, broccoli, celery, cucumbers, pears, and watermelon. Foods to promote Qi/Blood movement include eggs, crab, carrots, and turnips. Avoid hot foods such as lamb, corn-fed beef, chicken, and rice. Massage along the sides of the neck and lower jaw for 3 to 5 minutes twice daily.
- Local Qi/Blood Stagnation and Qi Deficiency - acute onset, stridor (upper airway noise and distress), tongue purple, history or physical evidence of trauma - treat using the herbal formula Bu Yong Yi Qi. Foods to move Qi/Blood include eggs, crab, carrots, and turnips. Avoid cold foods including duck, clams, barley, celery, cucumbers, and watermelon. Avoid hot foods including lamb, shrimp, and corn-fed beef. Massage along the sides of the neck and along the lower jaw for 3 to 5 minutes twice daily.
- Lung Qi Deficiency - exercise intolerance, weak voice, respiratory stridor (upper airway noise and distress), tongue - pale. The herbal formula Si Jun Zi Tang (Four Gentlemen) can help. Supplement diet with grass-fed beef, mackerel, rabbit, oats, chicken, herring, and yams to tonify Qi. Recipes to support the lung are recommended.
Most cases of laryngeal paralysis will show some improvement with acupuncture, particularly electroacupuncture.