Am i right that  yearly phpv test need to be done on stud dogs & bitches before mating ?? so if dog is to be used before he is aprox 12months but he has be litter screen (aht)& is clear could this be ok ?  thank you

Can anyone help answer this question please?

My understanding of PHPV is that the mode of inheritance is unclear although it is believed to be congenital, i.e. present at birth.

Further research is happening now and the SBT UK parent club & the AHT are asking for samples from affected dogs, their parents, grandparents etc to further this research.

http://www.staffords.co.uk/sbtbc/health_issues.htm
So, I would say yes, screening is necessary prior to mating.

This topic/same question was covered in this thread:

http://www.champdogsforum.co.uk/board/topic/130413.html

Apologies. I did not spot the other thread :) Thank you for taking the trouble to reply anyway.

Not a problem, happy to help particularly if it brings useful info to the masses :)