Also, I would put in a clear statement that "no cat will be allowed due to allergy, this includes service cat and emotional support cat". While Airbnb does have nondiscrimination policy in place for service animals, your allergy definitely serves as an exception that gives you the right to refuse any service animal or emotional support animal if it is a cat. Some guests with service animal or emotional support animal might have the illusion that since they are protected by the nondiscriminatory policy and should be allowed to book and stay anywhere that is not true at all. You need to clearly state this.