The present invention relates to: parasitic helminth cuticlin proteins; parasitic helminth cuticlin nucleic acid molecules, including those that encode such cuticlin proteins; antibodies raised against such cuticlin proteins; and compounds that inhibit parasitic helminth cuticlin activity. The present invention also includes methods to 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.