They are adjectives that all mean "like an animal" because they are derived from the Greek or Latin words for animals.
feline = like a cat.
canine = like a dog.
avian = like a bird.
equine = like a horse.
Bovine, ovine, lupine, feline, canine, vulpine...
If a dog-like animal is a canine then a cat-like animal is a feline.(Those words are taken from Latin, the original language used by the ancient Romans.)
If you mean the beagle puppy it is lou. If you mean the dog that ran away at the begining its Buddy.
equine
atrium, structure, canine
aqua equine equal
equine,equidox,equilibrium etc...
feline.
Aviation, avian, avuncular, aviatrix,avalanche, avoid.
Feline domesticated animals
K-9 is simply an abbreviation of Canine or another word for dog. It apparently originated in the military, where designations such as G-2 are common, making K-9 a rare official pun, being similar to "canine". The term, originally referencing war dogs, has since carried over to police, and sentry and assistance dogs as well.
Equine, equitation, equestrian, equidistant