Update...

Sadie's last meds were September 13th.  While we're not having any fights, there is some chasing going on.  Sadie is playing more and sleeping out in the open instead of under our bed.  She has some knots on her thighs that she will not let me tend to.  I can't get her to hold still long enough to either cut them out or comb them out, although she loves to be brushed just not in those areas.  She has continued marking - in my tub, the foyer on the closet door, the fridge next to the garage door and now in the dining room by the sliders.  What used to be a once in a while thing is becoming more often.  We can understand the doors, we have feral cats in the neighborhood and this is common behavior for territorial cats, but my tub?  Every morning we check the cat box and find that Sadie has not peed in any of them - it's easy to tell, she pees copious quantities while Sassy pees drops.  This morning there was no pee from either of them so either Sassy quit peeing or she's following Sadie's lead.  Either way, this can't keep up.  The occasional poop from Sassy on the carpet is easy to clean up and de-smell, pee is entirely another matter.  If she doesn't stop, I fear she'll have to go back on the meds full time.