Q: Are there laws to protect people who get attacked/chased by “service animals” who are not on leashes and aggressive?

A: Yes. Service animals are required to be under the owner’s control at all times. So the dog cannot chase and attack you and be exempt from the law. Such behavior could fall under Colorado’s dangerous dog statute. If you are being chased or attacked by any dog, regardless of designation, you can report the dog and owner to animal control or your local law enforcement.

A: You should talk to your landlord and document the issue and see if there is some neutral third party who could potentially mediate this issue. You say "they" as in more than one service dog. Typically a person only needs one service dog, but there are some exceptions. Is it possible these are actually emotional support animals? If so, they are allowed in no-pet housing only to the extent they do not interfere with other resident's enjoyment of premises, and they would not be exempt from leash laws. Your apartment does not appear to be no-pet housing, so I'm wondering why the owner feels the need to call the dogs his "service" animals? It may be helpful to look at Colorado's fake service dog laws embodied in House Bill 16-1426 (signed into law and codified in many different statutes). It says in part, "(a) Service animals that are properly trained to assist persons with disabilities play a vital role in establishing independence for such persons; (b) The term "service animal" has a distinct meaning in the law. A service animal means a dog or miniature horse trained to do work or perform tasks for the benefit of an individual with a disability and whose work or task is directly related to the individual's disability. Under the law, the provision of emotional support, well-being, comfort, or companionship does not constitute the work or tasks of a service animal."