Japan Rabies Prevention Law (狂犬病予防法) — Detention of Unregistered/Unvaccinated Dogs (Art 6)
Source: 狂犬病予防法 (Rabies Prevention Law, 1950 Law No.247), full statute text from laws.e-gov.go.jp, on disk as pdf-raw/jp-health/rabies_prevention_law.txt. The original-language text — not the English translation — is the verified C1 claim.
This P2 topic records the enforcement power under Art 6: a rabies-control officer (予防員) must detain any dog found unregistered/untagged or unvaccinated/untagged.
Claims (verified C1 substrings of source_file — original verbatim; English in parentheses)
予防員は、第四条に規定する登録を受けず、若しくは鑑札を着けず、又は第五条に規定する予防注射を受けず、若しくは注射済票を着けていない犬があると認めたときは、これを抑留しなければならない。(EN: A rabies-control officer who finds a dog that is unregistered or untagged under Art 4, or unvaccinated or lacking its vaccination tag under Art 5, must detain it — Art 6(1).)