Here's a few I found that I don't think have been mentioned:
Country: Sweden
Zoo: Orsa Rovdjurspark
Year: 2017
Circumstance: 19-year-old keeper killed while showing visitors the bear enclosure, which was supposed to be empty.
Teenage zookeeper killed by bear in Sweden - Radio Sweden
Country: Mexico
Zoo: Nicolas Bravo Zoo
Year: 2018
Circumstance: Keeper forgot to shut gate separating feeding and sleeping areas in the lion enclosure, was killed while cleaning.
Mexican zookeeper forgot to shut gate before killed by lion
Country: New Zealand
Zoo: Hamilton Zoo
Year: 2015
Circumstance: Zoo Curator killed by older female tiger.
Keeper killed by tiger at Hamilton Zoo
Country: India
Zoo: Bannerghatta Biological Park Zoo
Year: 2017
Circumstance: Killed by an 18-month-old white tiger while cleaning up after feeding. A sibling joined in after the keeper was dead.
Horror as zookeeper mauled to death by white tigers while he cleaned their enclosure
Country: China
Zoo: Fuzhou Zoo
Year: 2018
Circumstance: Keeper tilled by former circus tiger during training.
Country: United States
Zoo: Lincoln Park Zoo
Year: 1945
Circumstance: Worked killed by black bear while cleaning cage.
Country: United States
Zoo: San Diego Zoo
Year: 1942
Circumstance: Animal trainer attacked (killed?) by Himalayan brown bear.
Country: United States
Zoo: Denver Zoo
Year: 1934
Circumstance: Keeper attacked by two grizzlies after spraying them with hose.
Country: United States
Zoo: John Ball Zoo
Year: 1985
Circumstance: Jaguar opened automatic door and killed pregnant keeper.
https://www.upi.com/Archives/1985/12/13/Cage-door-blamed-in-fatal-jaguar-attack/1337503298000/
Country: United States
Zoo: Denver Zoo
Year: 2007
Circumstance: Jaguar got into employee access hallway and killed keeper.
Country: South Africa
Zoo: ??
Year: ??
Circumstance: Retired keeper returned to help cover staff shortages, was attacked and killed by 11 year old lion during feeding. Security gates had been left open.
Country: China
Zoo: Yeshanko Wildlife Zoo
Year: 2016
Circumstance: Idiot jumped into Walrus pool to get a selfie. Both he and the keeper who tried to rescue him were drowned.
Country: United States
Zoo: Miami MetroZoo
Year: 2016
Circumstance: Keeper didn’t see/ignored sign saying a tiger was in the paddock when arriving in the morning; tiger left out attacked when he opened the gate. Keeper had suffered a head injury from a rhino 4 days before and had been having vision problems, sleep issues as a result.
https://www.miamiherald.com/news/local/community/broward/article72217807.html
Country: United States
Zoo: Knowland Park Zoo
Year: 1991
Circumstance: Elephant attacked and killed handler
Country: United States
Zoo: San Antonio
Year: 1992
Circumstance: Elephant lifted keeper with trunk and slammed him down, killing him
Country: United States
Zoo: Lowry Park
Year: 1993
Circumstance: Elephant swatted handler to the ground with its trunk, kicked her in the head
Country: United States
Zoo: Pittsburgh
Year: 2002
Circumstance: Elephant pinned handler to ground during walk, killing him
Country: United States
Zoo: Knoxville Zoo
Year: 2011
Circumstance: Employee pushed into stall by elephant
Country: United States
Zoo: Dickerson Park
Year: 2013
Circumstance: Elephant killed keeper