I petsat in the past for two Brussels Griffons, both males. I didn't find them "high maintenance" really, just annoying. They had a lot of difficulty with housebreaking, probably because their owners weren't consistent. They were old enough that they should have been able to hold it much longer, but I had to take them out every two to three hours and watch them constantly when inside or they would have an accident. At night I attempted to let them sleep in the bed with me like their owners did, but they would inevitably wake me up at 3am by playing on top of me, and they would pee on the floor at night and sometimes poop, so I started having them sleep in their crates at night. But of course, they would whine and bark when in their crates. Sigh. I don't think they would have been quite so annoying if they had had proper, consistent training in their lives. They were NOT stupid dogs, they were just allowed to get away with murder, and they reveled in it.
"Give thanks to God for being dog. He gave us the joy of angels." - Trixie Koontz, Dog, Trixie Treats & Holiday Wisdom - Christmas is Good!