The Smithsonian article is bad. The writer doesn't even try hard to get her cat to do the experiment and has no results.
Better story in the linked original article in New Scientist: https://www.newscientist.com/article/dn17510-is-your-cat-lef...
And the abstract of the original study, since the whole article is behind a ridiculous paywall, part of the typical Elsevier scam of blocking science: http://www.sciencedirect.com/science/article/pii/S0003347209...