Next, no animals habitually prey on cats or small dogs. The only ones who reasonably could are large raptors (eagles or big owls)
Coyotes eating cats is widely reported.
Small dogs... mostly don't exist in the wild. Smallest I can think of is jackals. Or sub-adults in general, I guess.
Black-backed jackal wiki page has "Black-backed jackal pups are vulnerable to African wolf,[8] honey badger, spotted hyena and brown hyena. Adults have few natural predators, save for leopards and African wild dogs.[11]"
few predators, but two, one of them being a larger canine.
Golden jackal page: "Leopards and tigers once hunted golden jackals... Eurasian lynxes are also known to hunt golden jackals... Striped hyenas prey on golden jackals, and three jackal carcasses were found in one hyena den"
Now, I think that what you don't see is land vertebrate carnivores living primarily on other vertebrate non-insectivore carnivores. A big one will eat a small one if it gets the chance, but it's not a mainstay of the diet. Whereas in the ocean I think you can have bigger fish or mammals that largely live on smaller fish (or 'fish') that eat even smaller fish. Deeper trophic chain. Like sperm whales living on giant squid that aren't exactly herbivotes themselves.