It was exterminated in Hokkaido during the Meiji Restoration period, when American-style agricultural reforms incorporated the use of strychnine-laced baits to kill livestock predators.

In 1935, Pocock examined one of the specimens in the British Museum that had been obtained in 1886 and named it Canis lupus rex because of its large size.

[6][14][13] The Tsugaru Strait was 3 km wide during the last glacial period,[6][15] which prevented Ezo wolves from colonizing Honshu and they likely arrived in Japan less than 14,000 years ago.

The isotopic analysis showed that feeding habits of these wolves were similar to the modern "coastal" British Columbia wolf, with both populations dependent on both marine and terrestrial prey.

[22] A study of Ezo wolf morphology showed that it was similar in size to mainland Asian and North American wolves.

[23] Soviet zoologist Vladimir Geptner wrote that the wolves (classed under the nomen dubium C. l. altaicus) of Kamchatka (where C. l. hattai's range is supposed to have encompassed)[11]: p42  are just as large as C. l. lupus, with light gray fur with dark guard hairs running along the back.

[24] Edwin Dun, in his unpublished memoirs, described it in the following terms:[25] The Hokkaido wolf is a formidable beast but not dangerous to man as long as other prey is to be had for the killing.

Their large feet enable them to travel rapidly over deep snow that soon tires a fleeing deer that could easily run away from his enemy when the ground is bare.

They are widely scattered throughout the island as a rule but few in any one neighborhood.The Ainu revered the wolf as the deity Horkew Kamuy ("howling god"), in recognition of the animal's similar hunting habits.

Ohio rancher Edwin Dun was hired as a scientific adviser in 1873 for the Kaitakushi (Hokkaido Development Agency), and began promoting ranching with state-run experimental farms.