Laryngeal Paralysis In Dogs: Causes, Symptoms, Diagnosis, and Treatment
Wed, April 21, 2021

Laryngeal Paralysis In Dogs: Causes, Symptoms, Diagnosis, and Treatment

 

Laryngeal paralysis occurs when the muscles that open the voice box is weakened due to the deterioration of the nerves and muscles, stated Blue Pearl, a national network of specialty and emergency pet hospitals. This causes difficulty in breathing, especially when your dog is stressed or when it is exposed during hot, humid days.

Laryngeal paralysis will gradually affect all the muscles of your pet’s body, causing generalized weakness and difficulty in swallowing. Most dogs afflicted with this condition are geriatric, large breed canines. However, laryngeal paralysis is observed in young, large breed dogs, which is caused by an inherited genetic disease.  

Owners’ Perception of the Quality of Life and Cause of Death of Dogs With Late-Onset Laryngeal Paralysis (January 2020)

A total of 130 dog owners were qualified for the study and contacted for participation, said Susannah J. Sample and colleagues of Wiley Online Library, an American multinational publishing company. However, 36 did not respond to the email or phone request, 11 were not contacted as they lack current contact information, two declined to participate, and five did not answer all questions in the survey.

Overall, only 76 owners participated in the study. 72% of canines were diagnosed with LoLP (late‐onset laryngeal paralysis) at the authors’ institutional practice while 12% were diagnosed with LoLP and had an airway opening surgery at another referral practice. Only 16% were diagnosed through their primary care veterinarian. All dogs had evidence of hindlimb weakness and all 55 dogs evaluated at the researchers’ institutional practice had hindlimb paraparesis and decreased withdrawal reflexes. 43% underwent a glottic opening surgery while 57% did not.

All canines that underwent a glottic opening procedure were found to have gone through unilateral arytenoid lateralization. 55% died and 45% were alive at the time of the survey. The owners were asked how much time had passed from when symptoms of LoLP were first noticeable to when it had progressed to the point that they felt that their pet’s quality of life was compromised.

This was used as a proxy to assess the owners’ perception of disease progression. The most common response given by the owners was <1 year (36%), followed by 1-2 years (32%). 13% felt that LoLP progressed to affect their dogs’ quality of life >2 years after the onset of clinical signs. 14% did not know that their pet had LoLP before it was severely affected by the said condition. Only 5% said that they did not feel that LoLP affected their dog’s quality of life. Excluding owners who were incognizant of their dogs’ LoLP until their pets were severely affected, 94% felt that the condition progressed to affect the quality of life of their dogs.

The researchers tackled the degree to which owners felt LoLP led to their dog’s cause of death or a decision to perform euthanasia. They found that 33% of owners felt that LoLP did not contribute to their dog’s death. 19% said LoLP did contribute somewhat to their pet’s death even though it died from another condition. 9% felt that the condition was the primary, but not only, factor that led to their dog's death. Only 24% felt that LoLP was the sole reason for their pet’s death.

 

 

What Is the Larynx?

Also known as the voice box, the larynx is composed of the vocal cords to enable vocalization. The cartilages provide the larynx a “semi-flexible structure.” The arytenoid cartilages form the larynx’s “structural ‘doors’.”  Two sets of muscles are attached to the arytenoid cartilages: one set opens the “doors” while the other closes them. The glottis refers to the doorway where air passes from the mouth, to the windpipe, and to the lungs. When your dog swallows, the epiglottis—a valve that flips over the larynx— prevents food or water from being aspired into the windpipe.

What Causes Laryngeal Paralysis?

In most cases, the cause of laryngeal paralysis is unknown or idiopathic, Krista Williams, BSc, DVM; Ernest Ward, DVM, of VCA, an operator of over 1,000 animal hospitals in the US and Canada. Laryngeal paralysis can also be caused by trauma to the throat or neck, including tumors or space-occupying lesions on the chest or neck area. Hypothyroidism and Cushing's disease have been correlated with canine laryngeal paralysis.

What Are the Signs of Laryngeal Paralysis?

It varies. Laryngeal paralysis is an underdiagnosed condition as its initial symptoms only consist of shortness of breath, cough, and noisy breathing. Coughing, particularly after exercise or exertion, is the most frequently reported symptom of laryngeal paralysis. This is followed by noisy breathing, exercise intolerance, and dysphonia (or a change in the sound of the bark). Sudden, severe cases of laryngeal paralysis, your dog may develop respiratory distress along with cyanosis (bluish mucous membranes) of the mouth. Your dog may also collapse.

 

 

How Is Laryngeal Paralysis Diagnosed and Treated?

Diagnosis will be based on your dog’s medical history and clinical signs. Diagnostic tests may include blood and urine tests and chest radiographs. To confirm the diagnosis, your veterinarian will examine your dog’s larynx using an endoscope or laryngoscope. Your dog will be slightly anesthetized during the examination. Your veterinarian will evaluate the larynx as your pet breathes in and out.

Your dog breathes in and negative pressure from the windpipe pulls the arytenoid cartilages together, affecting the size of the glottis. In turn, this confirms the diagnosis of laryngeal paralysis. Mild cases can often be controlled with medications like anti-inflammatory drugs, sedatives, and antibiotics. Avoid exposing your dog to hot environments and engaging in strenuous exercise. Don’t use collars that put pressure on its neck. Consider using a harness if your dog has laryngeal paralysis. Surgery is recommended in severe or congenital cases of laryngeal paralysis.

The procedure will depend on the severity of your dog’s condition. One surgical technique is arytenoid lateralization by tie-back. The surgeon ties the collapsed cartilage to the side of the larynx to prevent any obstructions to breathing. However, your dog is more likely to be susceptible to anesthetic complications. Your veterinarian will inform you about these concerns, including the specific surgery technique before the surgery. Surgery is often effective in reducing or removing clinical signs. While it does improve your dog’s quality of life, surgery will not restore its laryngeal function.

Signs of laryngeal paralysis include coughing and noisy breathing. Medications such as sedatives can treat this condition. But in some cases, surgery may be needed to improve a dog’s quality of life.