My cat is usually really social. Is all over you at night meowing and wanting attention. For the past few days, he spent the nights sleeping under the bench at the foot of the bed and doesn't come out, even for food and treats. Typically he eats so quickly that we have to keep him away from the other cats food!He doesn't want to go outside anymore, where normally he would cause havoc to be let out.

For reference, he is about five years old, an indoor/outdoor cat. I took him to the vet a few years ago and they noticed that he had a slightly enlarged heart.

What should I do? Is this a wait and see situation, or a call the vet in the morning one?