Based on the amino acid sequence of bovine rhodopsin, five peptides corresponding to the carboxyl terminus and one loop region have been synthesized. Rabbit antisera to these peptides recognize rhodopsin in whole bovine and dog retinas. Antisera were used to detect differences in specific regions of rhodopsin in dystrophic vs normal dog retinas. As detected on both "dot blots" and Western blots, rhodopsin from retinas of dystrophic dogs has a reduced reaction with antisera to peptides, Rhod-4 and Rhod-10 (# 341-348 and 232-239, respectively). Since these sites on rhodopsin are possible binding sites for transducin and rhodopsin kinase, an alteration in these regions would have profound effects in the dystrophic state.