Are cats susceptible to bed bugs?

Not really! It is remotely possible but highly unlikely a cat would ever carry a bedbug. Bedbugs are attracted towards the breath of humans when they are asleep not to cats and they make their hiding place close to where the human sleeps not where a cat sleeps. Bedbugs live on human blood not animal blood. In the extremely unlikely event of a bedbug finding a hiding place on a cat, such as under its collar, it will almost certainly leave that hiding place rapidly and find a better hiding place as soon as the cat wakes up and moves.