The Disease
Progressive retinal atrophy (PRA) is a leading hereditary cause of blindness in pedigree dogs as is its counterpart retinitis pigmentosa (RP) in humans. PRA shows genetic heterogeneity, as does RP, with several distinct forms already recognized and several more remaining to be investigated.
Pups show signs of night-blindness by 6 weeks of age. By the age of 1-2 years most affected dogs are completely blind.

The Trait of Inheritance
Mastiffs and Bullmastiffs exhibit the first, and so far, only form of canine Progressive Retinal Atrophy - PRA - that is inherited as a dominant trait. Therefore only affected or unaffected dogs can be found. The Mastiffs are affected by the late onset form of the PRA.

Since vision loss might be recognised first when the dog is several years old, it's important to determine the actual status of the dog before breeding it.

The mutation-based gene test and its advantages
Progress in molecular genetics has allowed the identification of the gene mutation responsible for PRA in the Bull and English Mastiff.
By DNA testing, the responsible mutation can be shown directly. This method provides a very high accuracy test and can be done at any age. It offers the possibility to distinguish between affected and clear dogs. This is an essential information for controlling the disease in the breed.

Requirements
The tests are performed out of  EDTA whole blood (1 ml). Testing is performed a few times per week at Laboklin. The results are due about one week after arrival of the sample in our laboratory.