Electroretinography is an examination method where the function of the retina is objectively assessed. In 2002 the European College of Veterinary Ophthalmology (ECVO) published a proposition to a standard on how to perform ERG examinations, to facilitate comparison of results and to make it possible to repeat examinations. The purpose of this study was to validate parts of the canine ERG protocol suggested by the ECVO. Our principal aim was to study if there is any interference at the recommended stimulus intervals for dark-adapted rod- and combined rod-/cone responses. The results show that there is an effect on the a- and b-wave amplitudes when different stimulus intervals are employed. When all examined intervals are pooled, there is an increase in the median b-wave to each consecutive dim, white (rod) stimulus in a series of four.

The aim of the study was to examine the retinal ON- and OFF-pathways of the canine electroretinogram (ERG). The ON- and OFF-pathways are used to distinguish objects from their backgrounds. A dark object is discernible from a lighter background using the OFFpathway and the ON-pathway is used to descry a light object upon a darker background. This study shows that the dog ERG has both ON- and OFF-responses and that these responses can be separated by prolonging the flash duration over 50 ms. The dog OFF-response waveform was more similar to the cat OFF-response than the human OFF-response (Frishman, 2006; Zrenner and Gouras, 1979). In this study six female three-year-old Beagle dogs were included. Both background and flash stimuli were provided by LEDs (light emitting diodes) with a wavelength of 470 nm, a wavelength that is absorbed almost as effectively by the canine M/L-cones as by the S-cones. These stimuli gave ERGs with both ON- and OFF-responses.

The purpose of this study was to compare normal electroretinographies (ERGs) from three different canine breeds in order to evaluate if there were any marked similarities or differences between these breeds as to ERG responses. It is known that healthy dogs from different breeds but also dogs within the same breed but in different age categories may have different appearances of their ERG responses. This may be a problem when evaluating if an ERG is normal or not from a dog within a breed not previously examined. Because of this it is important to obtain normal values for each breed and age group in order to be able to use these for later comparisons of ERGs obtained from individuals affected with various retinal diseases. In this study we have chosen to examine dogs within the three breeds: Labrador Retriever (LR), English Springer Spaniel (ESS) and Chinese Crested Dog (CCD). All of these breeds may be affected with hereditary retinal diseases such as Progressive Retinal Atrophy (PRA). It is possible that ERG-responses vary due to a number of different factors.