Tests for genetic defects of the CLCN1 gene, known to cause myotonia congenita in other canine breeds, such as American Bulldog (Rodrigues et al. 2020), Australian Cattle dog (Finnigan et al. 2007), Jack Russel Terrier (Lobetti 2009), Labrador Retriever (Quitt et al. 2018), and Miniature Schnauzer (Bhalerao et al. 2002) were negative. Here, CLCN1 is linked to Thomsen and Becker disease.