Cara
Did they have a warrant appropriately signed? Put a NO Trespassing sign (that complies to your state's specifications) and if anyone official walks onto the property ask them politely if they have a warrant.
I had a bad neighbor who reported me to the health department because of a compost pile with "animal feces" (which were rabbit's). When the woman knocked on my door I asked if she'd seen my sign abd did she have a warrant. She kept saying she had a complaint and "had to investigate." I told her she was welcome to investigate when she returned with a warrant. I never heard another thing.
I'd also consider asking those demanding a shot to sign an agreement that they're responsible for any ensuing damage to and health care costs for the animal.
Where there's a will, there's usually a way.