The person was told the law exists because I say it does. They MUST show you the statute. If they try to seize your animals be sure to request their statutory authority to do so. Many times it says they only have the right to seize an animal on the owners property if it is injured or abused. If it's not spelled out in the statute they have no right to seize your animal and are stepping beyond their authority and become personally liable for their actions.
Most cities have a code of conduct that prohibit employee's from stepping beyond their authority.
If they are looking for something, they MUST have a search warrant. Demand to see a copy. They may threaten to arrest you for obstruction of justice. Don't fall for it, until they can provide you with their statutory authority for whatever they want to do, you are not obstructing justice and only standing up for your rights. You may have to explain to them that you are not obstructing justice and you will comply with their wishes as soon as they can either come up with their statutory authority or a court order.