Canid and canine generally mean any of the dog-like animals: domestic dogs, wolves, fox, coyotes, dingoes, jackals, wild dogs

Parrot applies to members of the Psittacine family: parrots, macaws, parakeets, cockatiels, cockatoos, parrotlets, lorikeets

Herps and herpetofauna are used to collectively refer to amphibians and reptiles: frogs, salamanders, newts, lizards, turtles, snakes

Bear means all actual bear species but is also often used in reference to pandas and koalas (just don’t say it in front of my scientifically accurate kid)

Waterfowl is ducks, geese, swans

Depending on why or how you’re using categories, you can also group by characteristics: Do they have fur, feathers, or scales Do they lay eggs or give birth Are they predator or prey Do they eat meat, plants, fruit, pollen, or some combination

southsamurai has a great overall explanation. I would add it also depends on the age and any medical conditions of each.

We have a 45 pound dog (age 12) and a 15 pound cat (age 17). The dog is on senior/old man food but is otherwise in good health. The cat has kidney disease so we have to get only specific kinds. Per month the cat’s food is about $5 more than the dog’s, but that’s for a smaller amount.