October 22, 2018

Multifocal chorioretinal lesions in Borzoi dogs

Multifocal chorioretinal lesions in Borzoi dogs

The appearance of unique retinal lesions in the eyes of Borzoi dogs, in Canada, became prevalent and known around the year 1977, and in recurring years, 1989 and 1995.  Further study showed that around 14% of Borzoi dogs seem to be affected by these retinal lesions with males being near four times as likely. With no sign of it being connected to coat color, researchers debate between whether the different types of lesions represent completely different diseases or simply multiple forms of a disease. Due to relative lack of knowledge on the connections and circumstances of these retinal legions, dog breeders are confused and hesitant in breeding dogs with a poorly known uncontrollable eye problem.


And so this article sets out to see if there is an association between PRA and Borzoi retinopathy and to identify an etiology and pathogenesis for this disease in Borzoi dogs.


The full article can be found here: https://onlinelibrary.wiley.com/doi/full/10.1111/j.1463-5224.2005.00423.x


One hundred and three Borzoi dogs ranging from about 8 weeks to 11 years old, with a near one to one ration of male to female dogs were tested with additional tests on a series of puppies and one dead neonate produced from a lab-breeding of two affected dogs. All dogs eyes were clearly examined by biomicroscopy and indirect ophthalmoscopy, and having topical tropicamide applied to their eyes. Photos were also taken of their eyes and tested for signs of blindness. There was about a resulting 12% of the dogs found to have focal retinal degeneration, similar to other studies done in previous years. Choroidal degeneration was found with these lesions leading to possibly reclassifying the lesions as chorioretinopathy rather than retinopathy.


In conclusion, the large number of Borzoi dogs with focal retinal degeneration and the tendency for lesions to occur repeatedly with other closely related sight leads, to believe that there is an inherited and familial etiology at play.  


Storey, Eric S., et al. “Multifocal Chorioretinal Lesions in Borzoi Dogs.” Veterinary Ophthalmology, vol. 8, no. 5, 21 Sept. 2005, pp. 337–347., doi:10.1111/j.1463-5224.2005.00423.x.


Access full article at : onlinelibrary.wiley.com

Reviewed by Sydnie Dillon, 10/22/2018