The effect of repeated eye examinations and breeding advice on the prevalence and incidence of cataracts and progressive retinal atrophy in German dachshunds over a 13-year period

Objective To analyze the change in prevalence and incidence of hereditary eye diseases (HED) in dachshunds due to breeding regulations based on biennial examinations performed by the German panel of veterinary ophthalmologists (DOK) from 1998 to 2011. Animals included A total of 12 242 dachshunds examined by the DOK and pedigree data of 318 852 dachshunds provided by the German Dachshund Club (DTK). Procedures The prevalence of congenital cataract (CC), distichiasis (DIST), hereditary cataract (HC), persistent pupillary membranes (PPMs), persistent hyperplastic tunica vasculosa lentis / persistent hyperplastic primary vitreous (PHTVL/PHPV), progressive retinal atrophy (PRA), retinal dysplasia (RD), and findings such as fiberglass-like cataract (FGC) and prominent suture lines (PSLs) was analyzed. The significance (P), confidence interval (CI), odds ratio (OR), relative risk (RR) and inbreeding coefficients (F) were calculated and P < 0.05 was considered significant. The incidence was evaluated based on affected dogs within birth cohorts from 1993 to 2006. Results The prevalent conditions studied were as follows: CC 0.5%, DIST 6.7%, HC 3.9%, PPMs 8.4%, PHTVL/PHPV 0.4%, PRA 1.5%, RD 0.2%, FGC 2.2%, and PSL 1.5%. The incidence of PRA decreased significantly from 6.0% to 0.6% for dogs born from 1993 to 2006, while HC showed a decreasing trend from 8.7% to 3.1%. More males than females were diagnosed with HC and PRA. Dachshunds with HEDs had an F that was not significantly higher than that of healthy dachshunds. Conclusions The decreasing incidence of PRA and HC in dachshunds supports the use of frequent HED examinations in combination with breeding control.