Final answer:
A spay can indeed be performed on an animal in estrus, though it is typically associated with higher risks due to increased blood flow to the reproductive organs during the 'heat' cycle.
Step-by-step explanation:
It is true that a spay can be performed on an animal in estrus. In estrus, also known as 'heat,' the animal is hormonally prepared for mating due to increased levels of certain hormones. During this time, the female is receptive to males and is capable of becoming pregnant. However, veterinarians can perform a spaying surgery during this time, which involves removing the female's reproductive organs to prevent pregnancy. This surgical procedure is routinely done to manage pet populations and can be performed at various stages of the reproductive cycle, although certain risks might be higher during estrus due to increased blood flow to the reproductive organs.