Sorry Neal, that manager is wrong. Federal ADA guidelines define service animals as dogs or rarely miniature horses. Emotional support animals can be pretty much anything and is governed by the FHA. While you are not allowed to ask what the disability is that they need the animal for, you can ask for documentation from a physician stating that it is indeed a support animal. Unfortunately, this isn't as difficult for them as it used to be... It doesn't matter if you have species or breed restrictions, have size restrictions, or don't allow pets as a whole, they have to be allowed if documented. They are not considered pets and so cannot be restricted. You also can't charge a pet rent or pet deposits... again, they're not "pets." Even counties or municipalities like Denver that have Pit Bull restrictions still have to allow Pits In if they are "support animals."
That being said, you can keep them to the terms of your pet agreement, if the animal is aggressive or destructive or if the owner doesn't pick up after it you can evict or charge for damage caused by the animal just like you would any other pet damage.
Reference:, 1993 WL 268293. The court found there that the landlord did not fail to properly accommodate a tenant's disability after the tenant was evicted for his demonstrated inability to comply with the plaintiff's pet policy," which included cleaning up after the dog and toileting the dog in a designated area.