J Vet Sci.  2013 Mar;14(1):77-84. 10.4142/jvs.2013.14.1.77.

Electroretinography recordings using a light emitting diode active corneal electrode in healthy beagle dogs

• Itoh Y
• Maehara S
• Itoh N
• Yamashita
• Izumisawa

• KMID: 1482816
• DOI: http://doi.org/10.4142/jvs.2013.14.1.77

Abstract

Electroretinography (ERG) is a well-established diagnostic procedure for objectively evaluating retinal function. In this study, ERG in beagle dogs, which are a popular experimental animal, was performed to determine the normal range of ERG variables and assess differences between the left and right eyes. ERG findings including rod, combined rod-cone, single-flash cone, and 30-Hz flicker responses were recorded with an LED-electrode in 43 sedated beagle dogs. The subjects were divided into young (< 1 year old), adult (1~5 years old), and senile animals (> or = 6 years old). Normal ERG ranges were obtained. Significant differences in b-wave amplitude along with b/a ratio of the combined rod-cone response were found between the young and adult animals as well as young and senile dogs. No significant differences were observed between the left and right eyes. ERG variables in beagle dogs differed by age due to age-related retinal changes. Thus, we propose that normal ERG ranges should be determined according to age in each clinic and laboratory using its own equipment because each institution usually has different systems or protocols for ERG testing.

Keyword

age group; beagle dog; electroretinography; LED-electrode; normal range

MeSH Terms

Aging
Animals
Dogs/*anatomy & histology
Electrodes/veterinary
Electroretinography/methods/*veterinary
Female
Male

Figure

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  Fig. 1 Representative electroretinography (ERG) waveforms obtained from one dog in each of the three age groups. The top, middle, and bottom ERG traces correspond to the young, adult, and senile dogs, respectively. (A) Rod response. (B) Combined rod-cone response. (C) Single-flash cone response. (D) 30-Hz flicker responses.

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  Fig. 2 Differences in ERG components between the left and right eyes of 43 beagle dogs. (A) Implicit times. (B) Amplitudes. Rod: rod response, RC: combined rod-cone response, -a: a-wave, -b: b-wave, Cone-b: b-wave in single-flash cone response, Flicker: 30-Hz flicker response. Each error bar represents the SD.

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