Genetic basis - GM1 Gangliosidosis in Shiba Inu dogs is caused by a deletion of a cytosine nucleotide in exon 15 of the GLB1 gene (GLB1:c.1649delC), leading to a premature stop codon and a truncated, nonfunctional beta-galactosidase enzyme. The disease is inherited in an autosomal recessive pattern, meaning that affected dogs have two copies of the mutation, while carriers have one copy and are asymptomatic but can pass the mutation to offspring
Pathophysiology - The deficiency of beta-galactosidase causes accumulation of GM1 gangliosides and related substrates in lysosomes of neurons and other cells. This leads to progressive lysosomal storage, neuronal damage, loss of myelin, and brain atrophy. The central nervous system is severely affected, resulting in deterioration of neurological functions such as coordination and balance
Complications - Small stature or failure to thrive. Ataxia and loss of coordination ("wide-based gait"). Head tremors and motor dysfunction. Progressive loss of balance and inability to stand or walk. Neurological decline leading to inability to eat or drink. Death or euthanasia typically occurs by 12 to 15 months of age due to disease severity
Why This Matters to Breeders and Vets - This invariably fatal genetic disease heavily impacts Shiba Inu breed health and welfare. Breeders benefit from genetic screening to maintain breed integrity and prevent suffering. Veterinarians play a key role in early diagnosis, client education, supportive care, and advising on genetic testing importance. Managing this condition through genetics helps improve quality of life in the breed
