On the Sniff breed page, Golden Retrievers show moderate genetic diversity: mean heterozygosity about 0.28, ranking 28th most genetically tight of 107 ranked breeds, and between 25th and 31st when its dogs are resampled (n = 3,523 dogs in the atlas cohort). An independent study that measured diversity in different dogs on a different genotyping array (Bannasch et al. 2021) ranks the 83 breeds both cover in close agreement (rank correlation 0.808).
Among ranked breeds, that diversity measure ranges 0.14 (least diverse) to 0.40 (most diverse). Higher means a more diverse gene pool on average; lower means more attention to recessive-risk testing is warranted, not that any one dog is doomed.
This is a breed-level population fingerprint from typed-backbone SNPs, not a pedigree coefficient of inbreeding (COI) for an individual dog, and not a health score. For the full dimensions and citations, see the Golden Retriever page.