the only thing i have found is to put "worn off" messages in its own window, and not use a pet on raids because of the spam. if im in a group with a bard, i just know ahead of time im not going to get a message when such and such's panther wears off so i do it the old way, cast on puppy first, then the other targets, when pets wears off i recast.
i do wish there was a way to filter pets worn off messages to a window seperate than other worn off messages, or filter it out all together, it is quite anoying, but something we have to live with in the days where we got to have all that silly extra stuff