Sample data:

Column 1 Column 2
Labrador Dog
Beagle Dog
Siamese Cat
Toucan Bird
Poodle Dog

In a separate spreadsheet, I am trying to create a formula that will search
in column 2 for "Dog" and return all individual instances in column 1 in
separate rows:
Labrador
Beagle
Poodle

Any suggestions?
Thanks!