Introduction The study of naturally occurring diseases in animal eyes may afford valuable insight into similar human diseases. In addition, these animals may provide a reservoir for in vivo therapeutic experimentation. Among previously reported eye diseases observed in various animals are conjunctivitis, keratitis, corneal ulcers, corneal dystrophies, uveitis, glaucoma, cataracts, progressive retinal atrophy, retinal detachments, cystoid degeneration of the peripheral retina, and various congenital anomalies.1-7 Although congenital and secondary retinal detachments have been reported in animal eyes, idiopathic retinal detachment, if it occurs, appears to be extremely rare. The present study concerns the spontaneous occurrence of retinal breaks without detachment in the senile dog retina. The gross and microscopic pathology of these lesions will be discussed with particular emphasis on the comparison of these lesions to similar findings in the human eye. Materials and Methods One hundred canine eyes were enucleated from 50 senile dogs within one-half hour of