4. Sudden paralysis of the hind end
While we’re on the subject of pain, this is one of the most truly painful cat emergencies: aortic thromboembolism, or ATE.
ATE is a complication of heart disease in cats in which a blood clot lodges in the rear (usually) legs. It causes sudden paralysis of the hind end.
Affected cats usually will pant, vocalize and show other signs of distress. It requires immediate veterinary attention.