Has not been tested with cats but he's extremely easy going and we would not suspect him to have any problems with them! He loves his humans and has been in a foster home with 3 Boston Terries for the last 3 months! He enjoys being anywhere you are! He does have very bad separation anxiety so he needs to be in a home where he will have someone close by at most times. Duke is heartworm positive and is receiving treatment. Because of this he is avaliable on a foster to adopt basis only until his heartworms are gone!