Evidence ledger
Similar samples, different questions.
Three peer-reviewed studies include Shaanxi-associated sighthounds. Their statistics are not interchangeable, and their population labels are not perfectly consistent.
| Study | Sample label | Sample | What it contributes |
|---|---|---|---|
| Yang et al., 2019 | “Shanxi Xi dog” / C_SXX | 12 | SNP-based diversity, inbreeding coefficient 0.28 and LD extent 77.79 kb; the geographic spelling is inconsistent with Shaanxi usage. |
| Li et al., 2023 | Shaanxi Thin dog / ThCSX | 12 | Runs of homozygosity: FROH 0.26, 1,809 ROH and recent effective population estimate 36. |
| Li et al., 2023 MBE | Shaanxi sighthound | 7 | Whole-genome comparison across sighthounds; this sample clusters with European sighthounds in the reported analyses. |
Primary studies: Yang et al. (2019); Li et al. (2023), Frontiers in Veterinary Science; Li et al. (2023), Molecular Biology and Evolution.
2023 population study
Three numbers belong together.
The sampled Shaanxi Thin dogs had the highest FROHamong the fourteen populations in the study and more than three times the total ROH count reported for the sampled Shandong group.
That is a meaningful warning about homozygosity in the sampled group. It is not a national census, a count of living dogs or a direct diagnosis of disease. The recent effective population estimate of 36 is also a genetic model statistic—not 36 animals.
Claims that fewer than 200 “pure” dogs remain circulate widely, but no public, breed-level official census has yet been located that supports a current hard number.
Population history
East Asian origin is not the whole answer.
The 2023 whole-genome study placed its seven Shaanxi sighthounds close to European sighthounds in principal-component, tree and ancestry analyses—not simply inside an undifferentiated East Asian cluster.
That result is compatible with a complex history of contact and gene flow. It does not identify exact modern donor breeds or date the events. The same paper argues for multiple origins and extensive admixture across sighthounds, making a single east-to-west or west-to-east founding story too simple.
The 2019 study’s speed figure of 60 km/h was contextual description, not a Xigou performance trial. Candidate genes reported in selection scans are hypotheses for further work, not validated mechanisms of speed or endurance.
Health
The evidence gap is larger than the data.
There is no mature Xigou-specific literature establishing disease frequencies, longevity or screening baselines. Absence of published disease data is not evidence of exceptional natural health.
Findings from Greyhounds or Salukis should not be imported as Xigou facts. Useful next evidence would include geographically identified samples, genomic relatedness, standardised hip, eye and cardiac records, cause-of-death data and repeated sampling over time.