I've noticed people that actually need their service animal know the laws and regulations, and often reach out to the event providers beforehand or when they arrive, and it is often the people that decide to bring their pet(s) on a whim that seem to make a huge stink about it when they are told to remove their animal from the premises.
If you are an attendee with a service animal I highly recommend that you reach out to Policy Relations or Attendee Relations so that they may be able to provide you with the best information and/or provide for you disability services. Their contacts are available on the FanimeCon website.
https://www.fanime.com/info/attendee-services/Under the Americans with Disabilities Act, service animals are defined as
dogs that are individually trained to do work or perform tasks for people with disabilities. ADA regulations have a separate provision about
miniature horses that have been individually trained to do work or perform tasks for people with disabilities. State and local governments, businesses, and nonprofit organizations that serve the public generally must allow service animals to accompany people with disabilities in all areas of the facility where the public is allowed to go. A public accommodation may ask an individual with a disability to remove a service animal from the premises if the animal is out of control and the animal's handler does not take effective action to control it; or the animal is not housebroken.
Pets and emotional support animals do not meet the definition of "service animal," and therefore, are not allowed into the convention center.
However, if you are bringing a pet or ESA, you can have them accompany you
outside of the convention center, such as the plaza, sidewalk, or over at Cesar Chavez Park, granted that you are following San Jose's leash laws and your animal is under control.