The two animals don't seem engaged with each other -- that is, it doesn' feel like a battle.
There's a decent book called "Capturing Motion in Watercolor" by Douglas Lew with some techniques.
Artist here. I can understand using watercolor considering your circumstances. I got this book a while ago and really loved it. I think it could really help you as far as painting goes. On that note, check out some of Wassily Kandinsky's work. Some people theorize that he had synesthesia as well. I don't buy it but I can see how one could assume that.
There's been a lot of interest lately in the role synesthesia has had in art as well.