There are "pet safe" chemicals that most companies use on all locations, pets or not. I've had a pest control contract for the entire 5 years I've been in my house and never had an issue. I know he doesn't spray directly around the tank, but he definitely sprays in the same room. He uses one of those pinpoint type sprayers like you can use for weed killer (pump container & spray wand).
Typically, they only spray around entry areas which would be doors, windows, toilets, etc. so if your tank is away from those, you should be fine.