I had a litter about three years ago and buyer called to say that the dog has allergies to grass and oak. This is causing ear infections.

Neither parent had allergies and I only bred the bitch once (I did not own stud dog).

At what point do you stop breeding either of the parents because of passing allergies?

On a scale of 1 to 10 - (if hips and elbows were at 8 or 9 or 10) where do you place the seriousness of any allergy? How is this passed and how could you tell if sire or dam were fine - that they could pass allergies?

my guess is their vet talked them into the allergy test.
Had a family with the same issues, they kept him in the house and did every med known to man.
When he came to board with me and stayed outside most of the day on our farm he cleared up in the two weeks! I had plenty of grass, dirt, mold, whatever to show a reaction.
as soon as he went back to the other environment it started back up, they just could not fathom something in their clean house was causing the issue.??

If the 3 generations I have do not have allergy problems I do not worry about it being genetic, it is most likely environmental or nutritional.