Canines are common scavengers and hunters found all throughout Crawl. While they are among the weaker monsters you'll find, they are all faster than the average character and usually run in packs. They can mostly be found in the Dungeon and the Lair (especially in the hound-themed Lair ending), though a couple varieties can be found in more exotic locations. Many of them can be summoned with the spell Call Canine Familiar.
h Jackal - Low-level scavengers that inhabit the early Dungeon. Individually weak, but a pack can bring down a newbie adventurer if they catch him out in the open.
h Hound - Swift, solitary dogs found in the earlier portions of the Dungeon. Quite delicious.
h Wolf - Fast creatures found in wild places, as well as in the company of Grum.
h Warg - Huge, bestial wolves who live in the Orcish Mines with their orcish masters. Resistant to poison.
h Hell hound - Demonic, fire-breathing dogs found mostly in and around the Hells. Occasionally appear elsewhere, such as with Azrael.
h Raiju - Abyssal wolves that can transform themselves into bolts of lightning and lunge through prey.
h Doom hound - Grim hunting hounds of Tartarus, their howls call down deathly hunters on trespassers.
h War dog - War-trained dogs with painful bites and a pack mentality. Found both in the Lair and in the company of Grum before their removal in 0.13.
h Spirit wolf - Semi-corporeal beasts that called vast packs to hunt those who enter their woods. Considered for inclusion in 0.14.