A number of test are available for the Golden Retriever and Labrador Retriever. Two or more of these tests purchased as part of this bundle will be discounted.
- Progressive retinal atrophy associated with the SLC4A3 gene (also known as PRA1)
- Progressive retinal atrophy associated with the TTC8 gene (also known as PRA2)
- Stargardt Disease associated with the ABCA4 gene
- Macular Corneal Dystrophy associated with the CHST6 gene
Progressive retinal atrophy (PRA)
Progressive retinal atrophy (PRA) is the most common form of inherited disease affecting the retina in dogs; the retina detects light and sends images to the brain. Progressive degeneration of the retina at the back of the eye is characteristic of PRA and leads to vision loss and blindness. PRA is not painful to dogs, and the first signs of the disease tend to be bumping in to objects, such as a piece of furniture that has been moved. Mutations in different genes cause genetically different forms of PRA. It affects many different breeds of dog, but each genetically distinct form usually affects one or a small number of breeds. At least two genetically distinct forms of progressive retinal atrophy are found in Golden Retrievers. Research suggests that there may be at least one form that has not yet been identified.
Progressive retinal atrophy (SLC4A3-type)
This specific form of PRA (also known as PRA1) is caused by a mutation in a gene called SLC4A3 and is indistinguishable from other forms of PRA in other breeds. The average age of onset of clinical signs is quite late, around 6 years, but can be variable.
Progressive retinal atrophy (TTC8-type)
A mutation in a gene called TTC8 causes this specific form of PRA (also known as PRA2). In humans TTC8 is also known as BBS8 and is associated with Bardet Biedl Syndrome and with non-syndromic Retinitis Pigmentosa. PRA is the primary feature in dogs homozygous with the mutation in TTC8, but they can also present with other characteristic such as obesity, renal anomalies, sperm defects and anosmia. The average age of onset of ophthalmic clinical signs is around 5 years, but can be variable.
Stargart disease is an inherited eye disease that affects dogs, primarily Labrador Retrievers. Onset of significant clinical signs is late in life, with affected dogs presenting with observable visual problems around 10 years of age. As with other retinal degenerations, such as progressive retinal atrophy, Stargardt disease is characterised by the degeneration of the rod and cone photoreceptor cells of the retina. Dog therefore experience visual deficits in bright and low light conditions. It is a progressive disease and symptoms will get worse as the dog ages.
Macular Corneal Dystrophy
Macular Corneal Dystrophy is an inherited and progressive eye disease. Initial clinical signs are cloudy corneas and/or visual impairment, first observed between four and six years of age. In addition, white/grey opacities are also observed. The cloudiness and opacities are caused by an abnormal accumulation of glycosaminoglycans in the cornea. MCD is progressive; as the density of the corneal haze increases, increased vascularization is observed and vision is increasingly impaired.