Sudden swelling of the face, lips, ears, and eyelids can be caused by a
hivelike allergic reaction called urticaria. The cat’s head may appear strangely out of proportion to
her body, and the eyes may be swollen shut. Common causes are food allergy, contact and inhalation
allergy, and the bites and stings of insects. Swelling may appear as much as 20
minutes after exposure to the allergen.
Treatment: Most reactions subside in three to four hours. Cool compresses
may relieve some discomfort. Your veterinarian may choose to administer
adrenaline or an antihistamine. You should try to find out what caused the
allergic reaction so you can prevent your cat from coming into contact with
that allergen again.
The following information isn’t intended to replace regular visits to your veterinarian. If you think your cat may have feline infectious peritonitis, please see your veterinarian immediately. And remember, please do not give any medication to your pet without talking to your veterinarian first.
The addition of wheezing, respiratory distress,
vomiting, or diarrhea indicates a potentially serious allergic
reaction. Snakebite is another possibility. Seek immediate veterinary
Head and Neck Abscesses
Head and neck abscesses appear suddenly and are accompanied by fever. They
are extremely tender and may give a lopsided look to the head, face, or neck.
Opening the mouth causes extreme pain in some cases. These cats refuse to eat
or drink. Many have a high fever.
WebMD Veterinary Reference from "Cat Owner's Home Veterinary Handbook"