We have several large feline species but no corresponding large canine species. I mean, if you look at a lion or a tiger, you have a really large cat. Even smaller cats like leopards, cheetahs, etc. are still really big cats. But, the largest existing canines are wolves which are really not a lot bigger than a large sheppard.
So, the question: why did large cats survive to the modern world where large canines did not?