I really don't know how they would be canned, especially since they would have to be pressure canned. This recipe I found is just to be eaten fresh.

PICKLED CHICKEN GIZZARDS

1 cup water
1 cup apple cider vinegar
1/2 cup sugar
1 tsp. salt
1 large onion, cut in 1/4-inch slices

Cook gizzards and drain. Bring first 4 ingredients to boil. Add gizzards and return to boil. Remove
from heat and add onion. Can add pickling spices if desired; in cheesecloth bag while boiling the first
4 ingredients.