Was it a true Service animal? If so I can see this happening. If it was an Emotional Support Animal it is yet another case where someone who doesn't want to pay a fee for their animal got to displace someone. Something really needs to be done about ESA's. Something like they need to be certified and trained like a service animal. If the animal is really providing this kind of service for your disability then you need to go through the process like any other person who needs a true service animal. And sorry, the animal needs to be able to really provide a service, not be a squirrel you happen to like. This is the most abused thing in aviation.