Sick as a Dog is the 18th episode of Arthur Season 1. It aired as the second part of episode 18. It day viewed on January 20 1997 with Arthur's Chicken Pox.
Pal eats things other than dog food, including pancakes, gummy worms, and hot dogs. Because of this, he gets ill. Arthur thinks D.W. had something to do with it since she always hated Pal.