Japanese Bobtail — questions to ask before paying a deposit
A responsible breeder will have these readily available. Deflection is a red flag.
Vertebral variation associated with the bobtail trait (HES7 gene)
The breed's short, kinked 'pom-pom' tail comes from a dominant HES7 gene variant that is essentially fixed in the breed — all 12 Japanese Bobtails sampled in the founding genetic study were homozygous for it. Radiographic surveys found associated changes confined to the tail region (a reduced caudal vertebra count, hemivertebrae, occasional anomalous ribs), but these did not correlate with pain, mobility problems or reduced lifespan, and the mutation is a different gene from the one that causes the Manx's tail loss and its associated serious spinal and pelvic defects.
Ask to see: No DNA test is commercially offered, and there is nothing to request here — the vertebral variation is expected for the breed and has not been linked to illness
OMIA — Tail, short and kinked (Japanese bobtail) (https://www.omia.org/OMIA001987/9685/) · Pollard et al. 2015, J Feline Med Surg (PubMed) (https://pubmed.ncbi.nlm.nih.gov/25488973/)