Cats in Hamburg, Germany: rules and travel
Hamburg requires every dog to be registered in the Hunderegister, microchipped and insured, and applies a citywide leash rule. Registering also registers the dog for dog tax.
Hamburg is a city state: the Hamburgische Hundegesetz and the dog tax apply citywide.
The national rules for Germany apply here too. National rules
Laws change: this is general information, not legal advice. The authority linked on each line has the final word.