Adjectives have 1 form for each gender/2 genders. So voc. sing. lun. for ñuha would always be ñuhus; it follows the declension of vala, voc. valus- voc. ñuhus. When you would call your cat, it would be: "Ñuhus kēlys!" (kēlius is reduced to kēlys via contraction).