Eye Conditions
Persistent Hyperplastic Primary Vitreous (PHPV)
This is a congenital condition (present from birth) in which there is a developmental defect in the normal regression of some of the intraocular structures of the eye. PHPV can range from being very mild to severe abnormalities which may lead to blindness.
The presence of mild abnormalities are usually seen as small brown pigmented dots on the posterior lens capsule. Previously the literature indicated that this was always observed as a bilateral phenomenon but recently it has been stated that affected dogs may show unilateral involvement, although this is less common.
The present knowledge of the mode of inheritance of this disease is thought to be an autosomal irregular dominant with variable expression. Due to PHPV seldom resulting in secondary cataracts in the Stafford, those that are mildly afflicted will seldom show any form of visual impairment during the course of their lives. Even those that are more severely afflicted, may be capable of adapting by using peripheral to compensate.
Stafford breeders should therefore not assume that the problem is absent simply because they have not encountered blatant signs of visual impairment, instead discerning breeders should ensure that all their Staffords are tested through the National Eye Scheme.