Yes, in addition to what aidan1970 said, let me clarify that my first paragraph was specifically related to me.

Also, aidan mentioned emotional support dogs - that's important. There are so many different names for animals that can be of help to someone with physical or mental health struggles (ie companion, mental health service, emotional support, therapy) it can be confusing. If an animal is used for emotional support or anything not for a disability it cannot be considered a "service dog." Phraseology is a real pain when it comes to this stuff. To make things interesting, if your tenant does say, specifically, that the dog is a service dog, general rule is you're basically obligated by law to take their word for it. (This is pretty controversial in regards to public places too, since anyone can take their dog somewhere, and if they say it is a service dog, that's all there is to it - all you can ask after that is what kind of service (work/task) the dog provides, not even what it's for or what the disability is, if the task is not obvious. For example, a seeing eye dog's task is pretty easy to spot, whereas a dog's task for agoraphobia is not.)

Once again, the liars and bad apples ruin stuff for everyone and make things difficult and complicated... As aidan said, depending on where you live and your renter/tenant situation, you may be able to ask for paperwork from a doctor saying the animal is a service animal (but again, not for what disability unless they offer that information freely). Other places, you still can only ask the two questions mentioned above. ....Which, personally, I think is pretty sketchy since ANYONE could cry "service dog" and pay no deposits or be allowed an animal in a place that normal doesn't allow them, etc... Anyway.

It would seem like a pretty special situation if your tenant's child was given a prescription for a true service dog for "just" ADHD, as again, legally a service dog is one that does tasks or work to aid, specifically, with a disability (physical or mental that prevents normal daily functioning), and a disability is something diagnosed/determined by a doctor. And who knows, maybe it is quite severe and they need the dog to help remind to take their medication or something. Don't think you mentioned age of the child, but if they are pretty young, I would think (or just hope) that responsibility would fall to the mother, though... Plus, if they randomly just picked up a puppy on short notice....Hrm. But who knows - I'm really not sure whether ADHD can be considered a disability or not by law.

However, even if they claim the dog is a service dog (true or not), if it is unruly/uncontrolled by the owner, causes damage or is not house-broken, and/or is a threat to anyone, the same rules apply as they would to any other dog or animal of a tenant. You can charge fees to repair damage or call animal control per the respective situation.

So, if they claim it is a service dog and you suspect otherwise, maybe call your city hall for information on what you can do where you live.