This debate among pet owners can still get quite heated.
In this short video, a scientist explains why she concludes that dogs have the greater cognitive capabilities:
Kathleen Crisley, specialist in dog massage, rehabilitation and nutrition/food therapy, The Balanced Dog, Christchurch, New Zealand
DoggyMom.com 
I haven’t watched the video, simply because in my humble opinion, both cats and dogs have their own special levels of intelligence. It doesn’t just extend to dogs or cats, either. Any animal, in fact, has their special unique intelligence factors that contribute to their abilities to survive. There are some animals that are much smarter than others, like dogs being more intelligent than cats. But, even in the canine family, there are some breeds which are less intelligent than others. And, I’m sure it’s the same in any *animal* kingdom family.