The electroretinographic phenotype of dogs with Golden Retriever muscular dystrophy.
OBJECTIVE
To characterize the flash electroretinogram (ERG) in the Golden Retriever muscular dystrophy (GRMD) dog and to compare the results with those from a control group of Golden Retrievers. To investigate whether similar abnormalities of the ERG as those found in a majority of human patients with Duchenne muscular dystrophy (DMD) are also observed in the GRMD dog, the canine model for DMD. Animals Five GRMD dogs and five age-matched clinically normal Golden Retrievers.


METHODS
An ophthalmic examination was carried out prior to performing electroretinography under general anesthesia. Rod, combined rod-cone and oscillatory potentials responses were recorded after dark adaptation. Responses to 30-Hz-flicker were recorded after light adaptation. The ERG responses of the GRMD dogs were compared with those of the control dogs by use of a Wilcoxon signed rank test.


RESULTS
GRMD dogs had significantly reduced a and b-wave amplitudes after dim white flash stimuli (rod response) and reduced a-wave amplitude after bright white flash stimuli (rod-cone response).


CONCLUSIONS
The ERG abnormalities observed in the GRMD dog suggest a dysfunction in the rod signaling pathway. These ERG alterations are different from those observed in human patients with DMD.
Beltran
W A
WA
Ophthalmology and Neurology unit, Department of Small Animal and Equine Medicine, National Veterinary College of Alfort, 7 avenue du Général de Gaulle, 94704 Maisons-Alfort, France. wab23@cornell.edu
Chahory
S
S
Gnirs
K
K
Escriou
C
C
Blot
S
S
Clerc
B
B
D000818:Animals; D001947:Breeding; D016022:Case-Control Studies; D004283:Dog Diseases / Q000235:genetics* / Q000503:physiopathology*; D004285:Dogs; D004596:Electroretinography / Q000662:veterinary; D020022:Genetic Predisposition to Disease; D008297:Male; D009137:Muscular Dystrophy, Animal / Q000235:genetics* / Q000503:physiopathology*; D010641:Phenotype; D012160:Retina / Q000503:physiopathology*