Eye Testing
In Australia a few breeders including us started testing eyes after a fellow breeder had a litter in 2016 with a puppy she suspected was blind.
She had the litter tested by an opthamologist and discovered that not only was Stevie blind, 2 of his litter mates were also confirmed to have the same condition, Optic Nerve Hypoplasia. One of those 2 is only partially vision impaired and the other quite blind in one eye.
At this same time 18 adults were tested by an ophthalmologist, among those Checked were Sire, Dam, Maternal Grandmother, Paternal Grandmother & Grandfather, Paternal Great-Grandmother, half siblings to litter, half siblings to dam, Uncle, Full siblings to sire, cousins, aunties. All 18 checked NORMAL for ONH.
One was dignosed with Geographical Retinal Dysplasia, but was deemed very mild and not to be affecting her sight at all.
At this point in time, we have not been able to find or even hear of any other instances of ONH (Optic Nerve Hypoplasia) in the White Swiss Shepherd either here or overseas.
We are following the advice of the veterinarian ophthalmologists and are implementing certified Eye Checks for our future puppies in order to ascertain if this was a one off developmental bad luck or bad genetic combo. There are quite a handful of eye conditions that can not be detected without an ophthalmology exam & people could be breeding from affected animals without even knowing it! Not all eye conditions cause total blindness like Mr Stevie Wonder.
She had the litter tested by an opthamologist and discovered that not only was Stevie blind, 2 of his litter mates were also confirmed to have the same condition, Optic Nerve Hypoplasia. One of those 2 is only partially vision impaired and the other quite blind in one eye.
At this same time 18 adults were tested by an ophthalmologist, among those Checked were Sire, Dam, Maternal Grandmother, Paternal Grandmother & Grandfather, Paternal Great-Grandmother, half siblings to litter, half siblings to dam, Uncle, Full siblings to sire, cousins, aunties. All 18 checked NORMAL for ONH.
One was dignosed with Geographical Retinal Dysplasia, but was deemed very mild and not to be affecting her sight at all.
At this point in time, we have not been able to find or even hear of any other instances of ONH (Optic Nerve Hypoplasia) in the White Swiss Shepherd either here or overseas.
We are following the advice of the veterinarian ophthalmologists and are implementing certified Eye Checks for our future puppies in order to ascertain if this was a one off developmental bad luck or bad genetic combo. There are quite a handful of eye conditions that can not be detected without an ophthalmology exam & people could be breeding from affected animals without even knowing it! Not all eye conditions cause total blindness like Mr Stevie Wonder.
Optic Nerve HypoplasiaThe optic nerves––located at the back of the eyes where they establish a direct connection to the brain––are responsible for vision. Optic nerve hypoplasia is a condition that uncommonly affects the optic nerves of cats and dogs, leading to a variable degree of vision reduction (or even blindness) in one or both eyes.
In some cases, the eyes of affected animals are otherwise normal. In other instances, the eyes are malformed in a variety of ways. In all cases, the optic nerves are smaller than they should be. Beyond an understanding of its genetic origins, exactly how this disease occurs is not well understood. Diagnosis usually occurs incidentally in the course of normal ophthalmic evaluation or because vision impairment is suspected. The animal may exhibit previously unrecognised evidence of blindness in one or both eyes (by failing to respond normally to light, unilaterally), in which case confirmation of the diagnosis occurs through fundoscopic examination (visualising the back of the eye with a lens) of a smaller-than-normal optic disc. |
