I'd say greyhound..
Does she shake uncontrollably at the vets? Like 90 percent of all the greyhounds I've worked on...
They are always such gentle and sweet dogs though.
You can use axii on your horse to lower her fear level.
Mounted combat is very strong. Hold the attack button down to slow time and connect for a instant kill.
Although I'd like to send roach to the glue factory most of the time.