BVA Eye Scheme

[tangy tango]

I know we have some experienced breeders on here, so hoping someone can answer this as I can't see to find the answer online.  It just seems to say an affected dog should not be bred from.

I understand that with PRA & FN both parents have to be carriers for a pup to be affected, so as long as one is clear the worst a pup can be is a carrier.  Does the same apply to an 'affected g' result on the BVA eye test?  I believe g stands for Glaucoma and the eye test looks for a predisposition to the disease, so the parent has a high risk of developing glaucoma at a later date?

[tangy tango]

In case I haven't explained myself very well 

I would basically like to know:

Affected g sire + Unaffected dam = ?  Could the pups inherit the g and therefore be at risk of developing Glaucoma?

Thanks in advance 

[Sharon]

Have a look at this leaflet Nick Burden gave me, regarding eye problems etc.  Glaucoma can be caused by two different causes, have a read through this: http://www.bva.co.uk/public/documents/Eye_Leaflet.pdf

[Jane S]

The Gonioscopy test for predisposition to Primary Glaucoma isn't straightforward - a fail gives an indication that the dog is at risk of developing Glaucoma in the future but it's by no means a certainty and depends on the severity of the goniodysgenesis - there are plenty of dogs who have failed this test and never develop Glaucoma and never produce it in their progeny. It comes down to how severely affected the dog is, but because the test result doesn't currently grade the degree of goniodysgenesis, all you see is "unaffected" or "affected"

The exact mode of inheritance isn't known for Primary Glaucoma in Cockers so you can't really compare it to conditions like PRA & FN which have uncomplicated modes of inheritance (simple recessives) and established DNA tests. All you can do is use your own judgment really - you wouldn't mate two dogs together if they were both severely affected with goniodysgenesis but if one is unaffected and the other only slightly affected, you're unlikely to get any problems.

[tangy tango]

Thanks for your replies and the leaflet, I think its the primary one I was thinking about. 

The mating in this case occurred a good few years ago, before the eye tests were carried out and results of the affected dog known.  We don't know if the sire has gone on to develop glaucoma or like you say Jane how affected he is.  Other dogs from the litter have tested unaffected but just wondered if it is worth getting progeny tested in this sort of scenario?