A genetic variant of the SLC7A10 gene has been identified as a possible causative variant for Paradoxical Pseudomyotonia (PP) in English Cocker Spaniels and English Springer Spaniels.

The disease can be characterised by the occurrence of movement-induced episodes of muscle stiffness, which resemble myotonia and can be present in varying degrees of severity. In most cases, the attacks are not painful and usually disappear on their own within 45 seconds. In severe cases, however, there may be life-threatening episodes of respiratory arrest and discoloration of the skin (cyanosis) due to a lack of oxygen.

In addition, when it is particularly cold or hot, even the slightest exertion can cause muscle stiffness and weakness. The first symptoms of PP can appear between the ages of 3 and 24 months. However, there is usually no increase as the disease progresses.

In dogs with mild symptoms, episodes can be reduced or even prevented by avoiding the typical triggers. In severely affected dogs with episodes of respiratory distress and cyanosis, drug treatment can reduce the frequency and severity of seizures.