Figure 1.

(A) Flow diagram, prevalence study—study phase I. ^aSix responders excluded because of euthanazia of the dogs before the age of 6, 5 because of incomplete questionnaires. ^bSixty‐one females and 62 males. ^cClinical signs reported by the owners, validated on subsequent telephone interview. (B) Flow diagram, litter cohort study—study phase II. ^aIdentified in study phase I (of all eligible Danish CKCS born in 2001). ^bExcluded because of euthanazia in 2001. ^cIncluding 11 dogs identified and validated in study phase I. ^dTen dogs excluded because of reluctant owners, 1 because of euthanazia, 1 because of severe heart disease. (C) Flow diagram of the 2012 long‐term follow‐up study—study phase III. ^aTwo owners declined to participate, 1 answer was excluded.