around the 18 to 20 week marker at the time I do P/H. I like it earlier because I want the info to make a decision for either selling or keeping a potential breeder.
If I have a guardian home already in place, I will wait until a year so I have the Patellas done for clearance at the same time.
Scores have been good (or not) from all the different timeframes. I did three at 18 weeks once and all fell between 70 and 80% P/H with a prelim of Good on one and I am waiting for the certified results of the other two as I did not Prelim them.
I have based my program on early P/H in most cases and have not had one fail OFA certification at 2 yrs. Two OFA scores have remained the same at certification but the rest dropped with one going from Fair to Good.
My experience with Wallace is not good - very inflated in his assessments. A nicely done report but not a practical tool to use for hip assessment WITHOUT a second hip test from P/H or OFA or BVA. My opinion, for what it is worth!