A cat would gag if his senses are overwhelmed by something like an unpleasant, overpowering, or strong smell. This reflex is developed to protect their lungs from inhaling foreign objects. If you see your cat constantly gagging, make sure to try and determine what might be the cause for this behavior by checking his environment. The things you should observe are the following:
Diffusing essential oils - the droplets from the diffuser can stick to your cat’s hair coat and could be ingested by your cat while grooming himself.
Perfume - if someone in the household wears strong-smelling perfumes, body spray, or heavy colognes, it could overwhelm your cat’s nose and cause him to gag
Frequent gagging could also be a red flag of an underlying health issue thus it’s a good idea to have your cat checked by your professional vet Ashburn VA.