An Etymological Dictionary of the German Language/Kitze
Kitze (1.), f., from the equiv. MidHG. kitze, kiz, n., OHG. chizzî, kizzîn, n., ‘kid’; from Teut. *kittîn, n., with the original dimin. suffix -îna, which appears in Küchelein and Schwein. Goth. *kidi (kidjis), n., may be deduced from OIc. kið, n., ‘she-goat,’ whence E. kid is borrowed (an E. word cognate with Scand. must have had an initial ch). Further, the assumed Goth. *kidi and *kittein, with medial dentals, are related to each other, just as the forms assumed under Ziege, tigô and tikkein, with medial gutturals. The close correspondence between Kitze and Zicke proves that they are related; both are pet names for Geiß, ‘goat’ (comp. Swiss gitzi for OHG. chitzî).
Kitze (2.), Kietze, f., ‘kitten, kid, fawn,’ not found in MidHG. and OHG., but probably existing in the vernacular, as is indicated by the specifically HG. tz compared with LG. tt (kitte); comp. MidE. chitte, ‘kitten,’ from an unrecorded AS. *citten (E. kitten); MidE. kitlung, E. kitling, are probably borrowed from Scand. ketlingr, ‘kitten.’ The cognates are related by gradation to Katze.