My apologies if this link has been posted previously, but I can not find it in Rootschat. The Canadian Veterans death notification cards have not been indexed, so a manual search is required. Following is extracted from the Library & Archives Canada website.
"When Veterans Affairs (Canada) was notified of the death of a First World War veteran, a death card was created and those cards are now in the custody of Library and Archives Canada and are used as a finding aid to the personnel records of the First World War. These cards are the extent of this set of records; there are no files relating to the notification of death.
There are approximately 130,000 cards, which are arranged alphabetically in 99 cabinet drawers. The contents of each drawer were digitized as a batch of approximately 1300 cards each. The name on the first card in a drawer is the title of that group of cards.
You can move through the images one by one, or skip ahead by entering a new page (image) number in the page navigation box.
http://www.collectionscanada.gc.ca/microform-digitization/006003-110.02-e.php?&q2=36&interval=50&sk=0&&PHPSESSID=iob4e6ep4ablcosh18bubv7bk5