The LPPN3 is another mutation that causes Laryngeal Paralysis - Polyneuropathy in Leonberger. It has also been found in Labrador Saint Bernard. Affected leonberger puppies usually develop severe symptoms of laryngeal paralysis at young age including breathing difficulty which is often loud and gagging, difficulty in swallowing food, hanges in barking frequency and quality, high-stepping and uncoordinated gait, stumbling and tripping, exercise intolerance, and muscle atrophy.
Symptoms and Impact
Affected Leonberger puppies often develop severe symptoms at an early age, including:
- Breathing difficulties, often accompanied by loud, gagging sounds
- Trouble swallowing food
- Changes in barking, such as hoarseness or altered frequency
- Uncoordinated gait, high-stepping movement, stumbling, and tripping
- Muscle atrophy and exercise intolerance
These symptoms are caused by degeneration and atrophy of the muscles that control laryngeal function, leading to impaired airflow in and out of the trachea. This results in noisy breathing, wheezing, and a characteristic roaring sound (stridor) in affected dogs.
Genetic Basis and Disease Progression
The LPPN3 mutation in the CNTNAP1 gene disrupts nerve function, leading to polyneuropathy. While most cases have been documented in Leonbergers, researchers have also identified affected Labrador Retrievers and Saint Bernards, showing variations in age of onset and severity.
In Leonberger there two more mutations known to cause the disease LPN1 and LPN2, the three tests are recommended for complete diagnosis:
