2023 study
Three numbers belong together.
The Shaanxi Thin dog sample had the highest run-of-homozygosity inbreeding coefficient among the fourteen populations in Table 1, approximately double the Shandong Thin dog value.
The same table reports 1,809 runs of homozygosity in the Shaanxi group and 482 in the Shandong group. The paper’s authors describe the difference as evidence of much higher inbreeding in the sampled Shaanxi population.
Primary source: Li et al. (2023), Genomic selection analysis of morphological and adaptation traits in Chinese indigenous dog breeds.
Read before repeating
What the paper does not prove.
It is not a national population estimate.
Twelve sampled dogs cannot tell us how many purebred Shaanxi Xigou remain across China. Population claims in the low hundreds circulate online, but we have not found a primary census adequate to publish as a hard number.
Effective population size is not the headline.
The paper reports a recent effective population estimate of 36 for the Shaanxi sample, but six populations in the same table are lower. The stronger comparative signal is FROH.
The paper was designed around selection signatures.
Its ROH analysis is useful and peer reviewed, but it was not a dedicated conservation census. Future claims should be updated when broader sampling becomes available.
Population implications
What the signal suggests researchers should examine.
Broader sampling
Twelve dogs establish a signal worth investigating, not a complete map. Additional sampling should record location, kinship and selection criteria.
Genomic relatedness
Geographic separation does not guarantee genetic distance. Genomic comparisons can test whether regional groups retain distinct variation.
Transparent population records
Pedigrees, health results and genomic data become more useful when methods, missing data and unfavourable results remain visible.
Longitudinal evidence
Repeated sampling over time would show whether diversity is stable, declining or being reshaped by recent introgression.
Health
The evidence gap is larger than the data.
There is no mature, breed-specific health literature for the Shaanxi Xigou in English. That absence does not justify confident claims of “natural health.”
Population-level hip, elbow, eye, cardiac and DNA screening data would help establish a baseline. Until longitudinal evidence exists, lifespan and disease-frequency estimates copied from generic breed sites should be treated as unsupported.