It all started this morning. My mom said she saw my Jack Russel dominate my other dog, a dachschie/toy spaniel mix by standing over her and pinning her to the floor while my dachschie mix was laying on her back in submissive pose. But later today (twice) I saw the Jack Russel stand over my dachschie mix and it looked as if the JRT was trying to mate with her! And both the dogs are females and neutered! Is there something wrong with my Jack Russel? What should I do?! HELP!