What is GOLPP?

What Is GOLPP?

Geriatric Onset Laryngeal Paralysis & Polyneuropathy

For nearly four decades, literature has extensively documented the occurrence of late-onset, acquired laryngeal paralysis, a common condition primarily affecting older dogs, notably Labrador retrievers, as well as other purebreds like Golden retrievers, German Shepherds, Australian Shepherds, and Newfoundlands, along with mixed breeds. Initially termed "idiopathic laryngeal paralysis" due to the absence of a specific cause, it was generally believed to involve bilateral mononeuropathy. Clinical manifestations often include a change in bark, observed in roughly half of affected dogs, and symptoms such as gagging, throat-clearing, or coughing, frequently triggered by eating or drinking. The condition typically begins subtly, featuring signs of upper respiratory obstruction like stridor, dyspnea, and exercise intolerance. Exacerbation can occur with excitement, exercise, stress, or elevated temperatures, potentially leading to severe respiratory compromise and collapse. Veterinarians often encounter dogs with GOLPP during emergencies when they present with respiratory distress, which can be life-threatening and requires urgent attention (oxygenation, fluid therapy, sedation, and cooling, is crucial for managing acute respiratory distress and hypoxia). However, once the immediate crisis has passed, there are numerous interventions available to assist both the pet and the family. It is important to understand the entire disease process to help the dogs and family. Let's delve into the scientific understanding of GOLPP and it’s progression.

The Nerve of Science

Laryngeal paralysis occurs when there's a disruption in nerve signals traveling from the recurrent laryngeal nerves to the lower laryngeal nerves. This leads to weakened muscles responsible for moving the vocal folds and arytenoid cartilages, resulting in obstruction of the upper airway. Turbulent airflow over the arytenoids, covered in mucosa, can cause swelling, worsening the obstruction. In cases where only the recurrent laryngeal nerves are affected, there may be spastic paralysis, making it challenging to widen the glottis and insert a breathing tube. However, if both the cranial laryngeal nerves and recurrent laryngeal nerves are involved, as in Geriatric Onset Laryngeal Paralysis Polyneuropathy (GOLPP), the paralysis is more relaxed.

Causes of denervation

An inherited laryngeal paralysis has been documented in young Bouvier des Flandres (can be uni- or bilateral, is autosomal dominant and involves loss of motor neurons in the nucleus ambiguus). Similar findings have been reported in young Siberian Huskies and crosses, Alaskan huskies and Bull Terriers.
A suspected hereditary laryngeal paralysis-polyneuropathy complex has been reported in Dalmatians and Rottweilers in which affected dogs manifest signs of a generalized neuropathy.
There are several reports of a neurodegenerative disease in Rottweilers, different from the above. In these cases, dogs demonstrate progressive ataxia, tetraparesis and laryngeal paralysis, and on histology have widespread neuronal vacuolation and spongiform changes in their nervous systems.
Myasthenia gravis has been reported with laryngeal paralysis, and laryngeal paralysis can occasionally be the presenting clinical sign.
Four cases of spontaneous laryngeal paralysis in juvenile, white-coated German Shepherd dogs have been reported.
Traumatic laryngeal paralysis occurs sporadically with injuries to the neck or cranial thorax (e.g., bite wounds).
Iatrogenic trauma to the recurrent laryngeal nerve(s), during procedures such as tracheal surgery, PDA surgery, pharyngostomy tube placement etc., could potentially result in temporary or permanent dysfunction. Usually this is unilateral, thus not of great clinical consequence.
Tumors such as thyroid neoplasia and cranial mediastinal masses can disrupt recurrent laryngeal nerve function, resulting in laryngeal dysfunction.
Laryngeal paralysis can be a manifestation of any generalized neuropathy or myopathy including vagal neuropathy.
Spasmodic dysphonia is a rare condition in the dog, where the nerves do not function symmetrically. Although intermittently stridorous, these dogs are not in great respiratory distress.
Geriatric onset laryngeal paralysis polyneuropathy (GOLPP), previously called idiopathic laryngeal paralysis is by far the most common form of laryngeal paralysis in dogs. GOLPP is seen mostly in middle aged to older, medium to large breeds such as Labrador and Golden retrievers, Irish Setters, Pointers, Afghans, Borzoi, Greyhounds, and mixed breeds. Male dogs are more frequently affected than females.

Treatment options

Definitive treatment of laryngeal paralysis currently consists of permanently pexying the glottis in an open position on one side (usually the left). See the Surgical Options page for more information.

The most significant complication post-surgery is aspiration pneumonia, occurring in approximately 10-20% of cases. This condition can arise immediately after surgery or develop months to years later. While initially linked to surgical procedures elevating the risk of laryngotracheal aspiration, it is now understood that esophageal dysfunction also contributes. Despite various proposed techniques to mitigate aspiration pneumonia risk, no prospective randomized studies have assessed their efficacy, leaving their impact uncertain. Effective management of esophageal dysfunction is strongly advised.

Esophageal dysfunction

Reduced esophageal motility resulting from simultaneous pararecurrent laryngeal nerve degeneration may increase the likelihood of dogs developing aspiration pneumonia. In a two-year prospective study, researchers evaluated esophageal function in dogs diagnosed with "idiopathic laryngeal paralysis" and compared it with age- and breed-matched controls. They examined the severity of esophageal dysfunction in relation to the incidence of aspiration pneumonia within the first year post-operation. Additionally, the study assessed the clinical neurological status of the subjects during each follow-up examination. Key findings from the study included:

1. Seventy percent of the affected dogs had esophageal dysfunction at time of presentation of laryngeal paralysis, most notable in the liquid phase.

2. Dysfunction was more pronounced in the cervical and cranial thoracic esophagus, coinciding with the innervation from the prLN. The pharyngeal phase of swallowing is typically normal. Feeding large sized kibble appears to stimulate a good contractile wave in the esophagus.

3. Dogs with the more severe esophageal dysmotility were at significantly higher risk of developing aspiration pneumonia.

4. Just under one third of affected dogs had generalized neurologic signs at the time of enrolment, and 100% dogs had signs of polyneuropathy at 12 months.

Current, generalized polyneuropathy

Recognition of the generalized nature of this condition has probably been hampered by the fact that the laryngeal surgery is usually performed in a referral setting, often in severely distressed dogs that present as emergencies and are not amenable to thorough neurological examination. Following surgery (or minimally stabilization from the respiratory event, dogs return to their primary veterinarian where any subsequent neurologic deterioration may not be recognized as associated with the laryngeal dysfunction. Without careful and rigorous neurologic assessment, early neurodegeneration may be misinterpreted as weakness from hypoxia, concurrent orthopedic conditions (which are also common in these dogs) or degenerative myelopathy (especially in German Shepherds). More recent data have shown that GOLPP affects many nerves (sensory and motor) in the body and that it progresses insidiously from the time of diagnosis and surgery. Surgical intervention still provides significant improvement in the quality of life for affected animals, but ongoing management needs to be provided for these cases, either by the specialist or, preferably, by the patient’s primary care physician.

Current approach to GOLPP

As veterinarians, we are faced with a slowly progressive deterioration of a much-loved family member. It is critical that we are fully aware of the natural history of the condition, how we can best manage the affected dog and support owners throughout the course of the disease.

We hope this website provides resources and information to help you, your patients with GOLPP and the families that love them.