Symptoms of heart disease in cats:

1. The most typical symptom of heart disease in cats is opening their mouths and panting. If the weather is not too hot and the cat does not exercise a lot, the cat often breathes laboriously and rapidly, and even coughs. That's probably a heart problem.

2. Cat heart disease often causes difficulty in standing and sudden paralysis of the hind legs. This is also one of the most feared complications, called "arterial thrombosis."

3. There are also a few cats with arrhythmia that may suddenly faint. This also means that they may have serious heart disease and must be checked immediately.

4. Cough, exercise intolerance, difficulty breathing, pale or cyanotic mucous membranes, and some may experience symptoms such as vomiting and shock.

5. The cat’s abdomen or chest has obvious ups and downs, or shallow and rapid ups and downs. This may be a sign that the affected cat is panting, but it is trying hard to endure it without forcing it to open its mouth to breathe.

6. Cats can also have fever due to heart disease, but it is difficult for the owner to feel it.