"163. (1) Every one commits an offence who
(a) makes, prints, publishes, distributes, circulates, or has in his possession for the purpose of publication, distribution or circulation any obscene written matter, picture, model, phonograph record or other thing whatever; or ..."
See: http://laws.justice.gc.ca/en/showdoc/cs/C-46/bo-ga:l_V-gb:s_163//en#anchorbo-ga:l_V-gb:s_163
Government Canada has a publication defining various forms of pornography. Bestial pornography is included under the definition of material classed as obscene. See
See: http://dsp-psd.tpsgc.gc.ca/Collection-R/LoPBdP/CIR/843-e.htm#fpornographytxt
The above link also served to discuss the potential culpability of service providers who assist in the conveyance of such material. Their role is unclear, although iStar - who blocked access to sites including bestiality - was judicially commended.