Greater Swiss Mountain Dog
The most carried tested variant is Bleeding disorder, in 21% of 59 Greater Swiss Mountain Dogs tested (Donner 2023), then Hyperuricosuria (4.2%). Only 16 dogs stand behind the atlas figures here, so little is known yet.
Also known as Great Swiss Mountain Dog, Greater Swiss Mountain, and Grosser Schweizer Sennenhund.
What genetic diseases do Greater Swiss Mountain Dogs carry?
From a panel of 250 Mendelian-disease variants screened in 1,054,293 dogs (Donner et al. 2023), Greater Swiss Mountain Dogs carry 2 of them at observable frequency. Carrier frequency is not clinical risk. Most recessive variants require two copies for disease expression; many dominant variants show incomplete penetrance. Read this as a population fingerprint of what's in the gene pool, not a per-dog prediction.
P2RY12what this gene does
P2RY12 is a gene that helps control how platelets stick together to form blood clots, which is essential for stopping bleeding.
For your dog: If your dog is from one of these breeds, it’s worth asking your vet about P2RY12 to understand any potential bleeding risks, especially before surgery or injury.
SLC2A9what this gene does
SLC2A9 is a gene that helps regulate uric acid levels in a dog's body. It plays a role in how the kidneys handle this substance.
For your dog: If your dog is one of the breeds known to carry this gene variant, it’s worth discussing with your vet to understand any potential urinary health concerns.
Other names
The Greater Swiss Mountain Dog is also recorded as Great Swiss Mountain Dog, Greater Swiss Mountain, and Grosser Schweizer Sennenhund.
Identified as Greater Swiss Mountain Dog (VBO:0200631) in the Vertebrate Breed Ontology (Mullen et al. 2025, CC-BY 4.0) · registry IDs FCI 58 · iDog 121 · VeNom 14447.
For researchers Population genetics, disease models and every recorded condition Open the research detail for the Greater Swiss Mountain Dog
In the atlas, the Greater Swiss Mountain Dog clusters consistently as Greater Swiss Mountain Dog (100% of the 16 dogs here). Dogs here sit in a relatively sparse region of the atlas, fewer close neighbors than typical.
Only 16 dogs of this breed in the atlas, modestly sampled.
What the atlas genotypes say about Greater Swiss Mountain Dog
Computed from the 14,478 CanVAS dogs in the Atlas, on an imputed genotype backbone: 77,215 directly typed sites per dog, imputed to 9.67 million variants.
The confidence below counts dogs, not reads: it is the size of the sample, and it is separate from how the genotypes were measured.
Not enough dogs in the atlas yet (n=16) for a reliable diversity figure. It fills in as more are added.
What does genetic diversity mean?
How varied a breed's gene pool is — the share of gene spots where a typical dog of the breed carries two different versions rather than two identical ones.
How to read it: Higher = more diverse. Among well-sampled breeds it ranges roughly 0.22 (least diverse) to 0.33 (most diverse).
Diversity is a strength, not a verdict on any individual dog. Lower diversity means it's worth paying attention to recessive-risk testing — not that a dog is doomed.
Not enough dogs in the atlas yet (n=16) to resolve cluster structure. It fills in as more are added.
What does within-breed variation mean?
How much individual dogs within the breed differ from each other genetically.
How to read it: Higher = more internal variety among individuals of the breed.
Sensitive to how many dogs of the breed we've sampled.
Greater Swiss Mountain Dogs are a natural model for human disease
Because the same genes cause the same conditions across species, the inherited conditions documented in Greater Swiss Mountain Dogs help researchers understand, and work toward treating, the human diseases they model. This is the dog advancing human medicine. The breed models the human disease; it does not have it, and this is not a prediction for your dog.
- platelet-type bleeding disorder 8, modeled by the breed's Bleeding disorder, P2RY12-related via P2RY12, the same underlying biology.
Every condition recorded in the Greater Swiss Mountain Dog
Beyond the testable carriers above, OMIA's literature catalogue records 1 genetic conditions in the Greater Swiss Mountain Dog, 1 of which have a known human equivalent. This is the documented landscape across all Greater Swiss Mountain Dogs ever studied, not a prediction for any one dog.
- Bleeding disorder, P2RY12-related Autosomal recessiveHuman equivalent: platelet-type bleeding disorder 8
Where every number on this page came from.
This page draws on three primary data sources. Carrier frequencies for the Mendelian section come from Donner et al. 2023 (CC-BY-4.0). We grade these data at evidence Limited because the cohort is a direct-to-consumer ascertainment, which biases toward owners who chose to test their dogs. The panel also uses tag-SNP proxies for some variants rather than direct causal-variant assays. Limited is a study-design grade, not a quality grade: the Donner cohort is the largest open canine-genotype dataset in existence and we are grateful for it. We rate the confounding MEDIUM.
Population-genetic dimensions (heterozygosity, intra-breed PCA distance, nearest neighbors, trait-locus frequencies) come from CanVAS (Brundage 2026), harmonized through the Sniff Atlas. The exact release date and verification commit are pinned at the bottom of the page so a researcher can trace a number back to a specific snapshot. The disease-gene-variant graph comes from OMIA (Online Mendelian Inheritance in Animals; Nicholas, Tammen, and the Sydney Informatics Hub at the Sydney School of Veterinary Science, The University of Sydney; retrieved April 2026, DOI 10.25910/2AMR-PV70).
What this page does not yet have. Inheritance modes and per-disease penetrance evidence from Donner 2023 are in the structured data for every variant the panel covers. Mondo, OMIM, Ensembl, and HGNC cross-references live on the gene and disease pages this page links to, rather than being repeated here. What is still absent from this breed page is anything not in the cited panel, and each such gap carries its cause where it appears.
How to cite this page. The computed dimensions on this page are derived from the open Sniff Atlas v1.0.1 (Gehring 2026, doi:10.5281/zenodo.20566358, CC-BY 4.0). Full citation formats including BibTeX, RIS, and CITATION.cff at sniff.world/cite.
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Lived experience, kept beside the science.We have 16 greater swiss mountain dogs. We do not have yours.
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- Donner J, Freyer J, Davison S, Anderson H, Blades M, Honkanen L, et al. (2023). Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLOS Genetics 19(2):e1010651. doi:10.1371/journal.pgen.1010651
- Brundage DM (2026). CanVAS: A Harmonized and Imputed Canine Variant Atlas. bioRxiv. doi:10.64898/2026.04.13.718238
- Nicholas, F.W., Tammen, I., & Sydney Informatics Hub. (2026). Online Mendelian Inheritance in Animals (OMIA) [dataset]. The University of Sydney. https://omia.org. doi:10.25910/2AMR-PV70 (retrieved April 2026).