Chickens are Galliformes and are prohibited.

Interestingly, pigeons are allowed and so are rabbits.  

TORONTO MUNICIPAL CODE

ANIMALS

SCHEDULE A TO CH. 349

PROHIBITED ANIMALS

MAMMALS

Artiodactyla (such as cattle, goats, sheep, pigs)

Canidae (such as coyotes, wolves, foxes, hybrid wolf dogs) except dogs

Chiroptera (bats such as fruit bats, myotis, flying foxes)

Edentates (such as anteaters, sloths, armadillos)

Felidae (such as tigers, leopards, cougars) except cats

Hyaenidae (such as hyaenas)

Lagomorpha (such as hares, pikas) except rabbits

Marsupials (such as kangaroos, opossums, wallabies) except sugar gliders derived from

self-sustaining captive populations

Mustelidae (such as mink, skunks, weasels, otters, badgers) except ferrets

Non-human primates (such as chimpanzees, gorillas, monkeys, lemurs)

Perissodactyla (such as horses, donkeys, jackasses, mules)

Proboscidae (elephants)

Procyonidae (such as coatimundi, cacomistles)

Rodentia (such as porcupines and prairie dogs) except rodents which do not exceed 1,500

grams and are derived from self-sustaining captive populations

Ursidae (bears)

Viverridae (such as mongooses, civets, genets)

BIRDS

Anseriformes (such as ducks, geese, swans, screamers) 

Galliformes (such as pheasants, grouse, guineafowls, turkeys)

Struthioniformes (flightless ratites such as ostriches, rheas, cassowaries, emus, kiwis)

REPTILES

Crocodylia (such as alligators, crocodiles, gavials)

All snakes which reach an adult length larger than 3 metres

All lizards which reach an adult length larger than 2 metres

OTHER

All venomous and poisonous animals

§ 349-4. Number of animals restricted.

Subject to § 349-17, no person shall keep in any dwelling unit more than six of any

combination of dogs, cats, ferrets and rabbits except that any person who, on the date of

the passage of this chapter, was lawfully keeping more than six of any combination of

dogs, cats, ferrets and rabbits may keep those dogs, cats, ferrets and rabbits until they

have died or are otherwise disposed of. 

Source:  www.toronto.ca/legdocs/municode/1184_349.pdf