Funduscopic abnormalities and electroretinography in cases of retinopathy in German Shepherd dogs Ireneusz Balicki,* Natalia Nestorowicz† and Ron Ofri‡ *Department and Clinic of Animal Surgery, Veterinary Faculty, University of Life Sciences in Lublin, Gleboka 30, 20-612 Lublin, Poland; †“Viva” Veterinary Clinic, Strachocinska 143 51-518 Wroclaw, Poland; and ‡The Koret School of Veterinary Medicine, Hebrew University of Jerusalem, PO Box 12 Rehovot 76100, Israel Address communication to I. Balicki Tel.: 48-81-445-61-57 Fax: 48-81-524-38-08 e-mail: balicki.ireneusz@gmail. com Abstract Objective To perform a clinical, ophthalmological, and electroretinographic assessment of retinopathic lesions in German Shepherd dogs. Animals The study was conducted on 14 German Shepherds diagnosed with retinopa- thy during the course of an ophthalmological checkup. The animals were systemically healthy police dogs used for patrolling and tracking duties and which were, at times, exposed to considerable physical strain and stress. Procedure Periodic ophthalmological examinations using slit-lamp biomicroscopy, direct and indirect ophthalmoscopy, and photography, as well as maze testing, were performed on all dogs. Electroretinography (ERG) was performed on 10 affected German Shepherds and eight control dogs. Results Ophthalmological examination revealed areas of tapetal hyper-reflectivity with pigmented centers, which were characteristic of inactive chorioretinitis. Most of the lesions were in proximity to blood vessels, and in a number of eyes, progression was observed during repeated examinations. Transition from active to inactive lesions, as well as onset in previously unaffected eyes, was also recorded. The ERG recordings showed impaired cone function, with significantly lower b-wave amplitudes and prolonged impli- cit times, in the mixed rod–cone, photopic, and flicker tests of affected dogs (P < 0.05). Conclusions Retinopathy observed in German Shepherd dogs is characterized by areas of tapetal hyper-reflectivity with pigmented centers. The underlying causes of retinop- athy in German Shepherd dogs remain unknown, although husbandry conditions and proximity of the lesions to blood vessels may suggest an association with physical exertion or circulatory disorders, respectively. Key Words: chorioretinitis, electroretinogram, German Shepherd dog, retinopathy INTRODUCTION Retinopathies are conditions that can be related to a vari- ety of causes. They may be classified as hereditary, acquired, retinopathies of specific etiologies, and retinopa- thies whose etiology remains as yet unknown. Hereditary retinopathies may be caused by several genetic mutations. Acquired retinopathies can result from viral, bacterial, fungal, protozoan or parasitic infections, as well as from immunological, or endocrinological diseases. They can also be caused by anemia, nutritional disorders, and cardiovascular disorders such as hypertension. 1–3 Acquired retinopathies often result from chorioretinitis and poster- ior uveitis. Retinopathy diagnosed during the course of active chorioretinitis and posterior uveitis is characterized by retinal edema observable as opaque areas; the borders of the inflammatory areas are often unclear. Retinal edema and exudate are present in the vicinity of blood vessels. Due to profuse cellular infiltration, grayish to white-col- ored hyporeflective lesions may form in both the tapetal and nontapetal fundus. Active inflammation may be accompanied by retinal bleeding and retinal detachment. Inactive chorioretinitis is a clearly distinct area of tapetal hyper-reflectivity often with a visible accumulation of black pigment in the center, with the lesion likely to be a scar resulting from previous focal chorioretinitis. 2,3 The accumulation of pigment in the center of the lesion is caused by pigment proliferation in the retinal pigment © 2012 American College of Veterinary Ophthalmologists Veterinary Ophthalmology (2012) 1–12 DOI:10.1111/vop.12007