Because a dog wouldn't be up that high.
Dogs will sometimes fall but they don't often find reason to get up on a dresser. Unless you leave a piece of pizza on your dresser, thereby creating an all-bets-are-off condition.
Other differences: When house-training, a puppy doesn't require expensive, perfumed, kitty litter. Any scrap paper is fine for a puppy. You could even train a puppy to pee on a US Senate budget proposal, assuming you could get the Senate to come up with one. (which they haven't in three (?) years and counting)
BTW - I wish I could remember the style rules for single digit numbers; I'm pretty sure you spell them out. I always have to try both ways to see which looks better. Like this:
Sandra Fluke is 3 decades plus a year old.
Sandra Fluke is three decades plus a year old.
See? At least when writing about middle aged women who try to pass themselves off as young college students, "three" looks better.
Yes definitely, like this: The three decades old student went on spring break with everyone else but she spent her time arguing with the hotel clerk about the sexism inherent in the system while her younger friends set their hair on fire and attempted to set records for alcohol poisonings per day.