The present invention relates to Dirofilaria ankyrin proteins and to Brugia ankyrin proteins; to Dirofilaria ankyrin nucleic acid molecules and to Brugia ankyrin nucleic acid molecules, including those that encode such ankyrin proteins; to antibodies raised against such ankyrin proteins; and to compounds that inhibit Dirofilaria or Brugia ankyrin function. The present invention also includes methods to identify and obtain such proteins, nucleic acid molecules, antibodies, and inhibitory compounds. Also included in the present invention are therapeutic compositions comprising such proteins, nucleic acid molecules, antibodies and/or inhibitory compounds as well as the use of such therapeutic compositions to protect animals from diseases caused by parasitic helminths.