Hereditary dystrophy of the retina and the retinal pigment epithelium in a strain of Briard dogs: A clinical, morphological and electrophysiological study
1994 (English)Doctoral thesis, comprehensive summary (Other academic)
A congenital hereditary retinal dystrophy was found in a Swedish strain of Briard dogs. A test breeding scheme produced a total of 6 litters of Briard dogs and Briard/Beagle crosses. A recessive mode of inheritance with a varying expression was observed. Visual impairment was evident at the first examination at 5 weeks to 10 months of age although the fundi of affected animals appeared normal, as seen by ophthalmoscopy. Nyctalopia was present in all dogs. Day vision was normal or nearly normal in the first litter. The other affected dogs showed severe visual impairment or blindness in daylight. During a 6-year follow-up, it was not possible to detect any decrease in visual ability. Low amplitude or non-recordable ERGs were diagnostic at the time of first examination, and onwards.
Electron microscopy showed disorientation of rod outer segments at 5 weeks of age. In older dogs, degeneration of photoreceptors was observed. This finding was most prominent in the peripheral parts. The rods were most severely affected. At late stages, severe changes were observed in the inner retina. Large electron-lucent inclusions accumulated in the RPE cells, mainly in the central parts, becoming more numerous and spreading towards the periphery with increasing age.
On DC ERG recordings, a high amplitude, negative, slow potential wasfound at the site of the c-wave. This negative potential may reflect a loss of the positive PI originating in the RPE. The functional changes correlated to the morphologic changes in the photoreceptors and pigment epithelial cells. The results show many similarities to congenital amaurosis in man and the presently described strain of Briard dogs may become an animal model of human visual cell disease.
Place, publisher, year, edition, pages
Linköping: Linköpings universitet , 1994. , 56 p.
Linköping University Medical Dissertations, ISSN 0345-0082 ; 423
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-28086Local ID: 12852ISBN: 91-7871-274-2OAI: oai:DiVA.org:liu-28086DiVA: diva2:248637
1994-05-13, Berzeliussalen, Universitetssjukhuset, Linköping, 09:00 (Swedish)
Papers, included in the Ph.D. thesis, are not registered and included in the posts from 1999 and backwards.2009-10-082009-10-082012-07-25Bibliographically approved