Yes, most species of flea are host specific and have developed adaptations which allow it to more successfully feed on a certain species of host.
The dog flea, for example, or Ctenocephalides canis lives primarily off of the blood of dogs. Another species of flea specifically targets cats as hosts. There are many different types of flea species which target specific animals as hosts.
Although fleas are host specific, they will not hesitate to feed on another available host if it’s primary source is not available. For example, dog and cat fleas will also feed on human blood if they are unable to obtain blood from their preferred source.