Do spayed female cats still go into heat?

Usually, cats won't go into heat after being spayed. Because the spaying procedure for female cats involves removing the uterus and ovaries, while the neutering procedure for male cats involves removing the testicles. These organs are the main areas where cats produce sex hormones ordinarily. As long as the surgery is successful, cats generally don't have the possibility of going into heat again.

However, even after cats undergo spaying or neutering surgery, the level of sex hormones in their bodies hasn't decreased completely in the short term. This part of sex hormones needs half a month to a month to metabolize. After the metabolism is complete, cats usually won't go into heat again.

If a cat still goes into heat after a period of time following spaying or neutering, there are three possible reasons:

The spaying procedure did not completely remove the ovaries or uterus, and the remaining organs grew back. The growth ability of the uterus and ovaries is very strong. If a simple uterine or ovarian ligature was performed, the remaining part would grow rapidly through collateral blood vessels. In this case, the cat may go into heat again.
There is cryptorchidism in male cats, and the cryptorchidism was not removed. Cryptorchidism in male cats is easy to detect. If you find that a male cat has only one testicle, it is likely to be cryptorchidism. The other testicle may be under the skin or in the abdominal cavity, which can only be confirmed by ultrasound. As long as the cryptorchidism is removed through a second surgery, the cat won't go into heat again.
Hormone secretion caused by abnormal glands. All hormones in animals' bodies are secreted by different glands. If the glands are abnormal, it will lead to the secretion of sex hormones and the cat may show signs of going into heat again. This requires professional examination for diagnosis.