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Saint Bernard

Life expectancy
9.3 years
95% CI 9 to 9.8 · McMillan 2024, n=1,129
Highest allele frequency
Degenerative Myelopathy
1.2% of gene copies · 721 dogs tested · Donner 2023
Behind this page
37 dogs
behind the atlas figures · an early sketch · 721 tested for variants

Saint Bernards have a cited life expectancy of 9.3 years (McMillan 2024 / VetCompass, n=1,129, 95% CI 9 to 9.8). The tested variant with the highest allele frequency is Degenerative Myelopathy, at 1.2% among the 721 Saint Bernards tested (Donner 2023; gene copies, not dogs). 37 dogs stand behind the atlas figures here, so treat this page as an early sketch.

Saint Bernard
Photo: Blanky · CC BY-SA 3.0 · Wikimedia

Also known as Alpine Mastiff (archaic), Bernhardiner, Saint, and St. Bernard.

See in the atlas → From CanVAS
Mendelian-disease genetics

Which disease variants turn up in Saint Bernards?

From a panel of 250 Mendelian-disease variants screened in 1,054,293 dogs (Donner et al. 2023), 9 turn up in Saint Bernards at observable frequency. The figure beside each is its allele frequency. Of the gene copies tested in this breed, the share that carry the variant. Every dog carries two copies, so this is not the share of dogs. It 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.

Degenerative Myelopathy (DM)
Autosomal recessive
low frequency band 1.2%
n = 721 dogs · 1 variant tested · OMIA:000263-9615 · omia.org →
SOD1what this gene does

SOD1 is a gene that helps protect cells from damage caused by harmful molecules called free radicals.

For your dog: If your dog is a carrier of SOD1 variants, it's worth discussing with your vet, but remember carrier status doesn't mean your dog will get the disease.

Cystinuria Type I-B (SLC7A9 p.A217T)
Autosomal dominant (OMIA); Autosomal recessive (Incomplete penetrance) (Donner 2023)
marker disputed 0.97%
n = 721 dogs · 2 variants tested · OMIA:001880-9615 · omia.org →
SLC7A9what this gene does

SLC7A9 is a gene that helps transport certain amino acids in the kidneys. It plays a role in how the body handles cystine, an amino acid that can form crystals.

For your dog: If your dog is a carrier, it’s worth discussing with your vet to monitor urinary health and catch any issues early.

Cone-Rod Dystrophy (cord1-PRA/crd4)
Autosomal recessive
low frequency band 0.56%
n = 720 dogs · 1 variant tested · OMIA:001432-9615 · omia.org →
RPGRIP1what this gene does

RPGRIP1 is a gene involved in the function of photoreceptor cells in the eye, which help dogs see in different light conditions.

For your dog: If your dog belongs to a breed known to carry RPGRIP1 mutations, it’s worth discussing with your vet to understand the risks and monitor eye health.

Collie Eye Anomaly (CEA)
Autosomal recessive
low frequency band 0.35%
n = 721 dogs · 1 variant tested · OMIA:000218-9615 · omia.org →
NHEJ1what this gene does

NHEJ1 is a gene involved in repairing breaks in DNA, helping maintain the integrity of genetic information in cells.

For your dog: If your dog belongs to one of the breeds known to carry this gene variant, it's worth discussing testing with your vet to understand any potential eye health risks.

Progressive Rod-Cone Degeneration (prcd-PRA)
Autosomal recessive
low frequency band <0.1%
n = 718 dogs · 1 variant tested · OMIA:001298-9615 · omia.org →
PRCDwhat this gene does

PRCD is a gene involved in the health of a dog's retina, the part of the eye that detects light and helps with vision.

For your dog: If your dog belongs to a breed known to carry PRCD changes, it's worth discussing eye health and potential genetic testing with your vet.

Dilated Cardiomyopathy (DCM)
Autosomal recessive
low frequency band <0.1%
n = 721 dogs · 1 variant tested · OMIA:002365-9615 · omia.org →
RBM20what this gene does

RBM20 is a gene that helps control how the heart muscle builds and repairs itself. It plays a key role in keeping the heart's pumping function strong.

For your dog: If you have a dog from these breeds, it’s worth discussing heart health with your vet, especially as your dog ages.

Dilated Cardiomyopathy risk factor (PDK4-related)
Multifactorial (OMIA); Autosomal dominant (Incomplete penetrance) (Donner 2023)
marker disputed <0.1%
n = 721 dogs · 2 variants tested · OMIA:000162-9615 · omia.org →
PDK4what this gene does

PDK4 helps regulate how cells use energy, especially in the heart muscle.

For your dog: If your dog is one of the breeds known to carry this gene, it’s worth discussing heart health with your vet, but being a carrier doesn’t mean your dog will develop disease.

Hyperuricosuria (HUU)
Autosomal recessive
low frequency band <0.1%
n = 721 dogs · 1 variant tested · OMIA:001033-9615 · omia.org →
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.

Ichthyosis
Autosomal recessive
low frequency band <0.1%
n = 721 dogs · 1 variant tested · OMIA:001588-9615 · omia.org →
PNPLA1what this gene does

PNPLA1 is a gene involved in maintaining the skin's barrier by helping produce essential fats that keep the skin healthy and hydrated.

For your dog: If your dog is from a breed known to carry PNPLA1 variants and shows persistent dry, flaky skin, it's worth discussing with your vet to understand if genetics might be playing a role.

Source: Donner J et al. 2023. Genetic prevalence and clinical relevance of canine Mendelian disease variants in over one million dogs. PLOS Genetics 19(2):e1010651 · Evidence: Limited (DTC ascertainment, tag-SNP proxy) · Confounding MEDIUM · License CC-BY-4.0 · Phene IDs from OMIA (Sydney School of Veterinary Science, The University of Sydney; DOI 10.25910/2AMR-PV70).
Sample size in this breed: 721 dogs from the Donner 2023 cohort.
In plain terms

What these results mean for a Saint Bernard

Degenerative myelopathy (DM)

About 1 in every 100 copies of this gene in the 721 Saint Bernards tested carry this change (Donner 2023).

  • DM slowly damages the spinal cord in adult dogs, until the back legs stop working. Nothing yet can stop it.
    OMIA 000263-9615

    “This is an adult onset degeneration of the spinal cord that progresses to paraplegia and tetraparesis. There is no successful treatment. A genetic test is available.” OMIA 000263-9615

  • Two copies of the SOD1 gene change mean a dog is at risk, not that it will get sick. Some dogs with two copies never do.
    OMIA 000263-9615

    “some homozygous mutant dogs had no signs of degenerative myelopathy, which suggests incomplete penetrance or other causative loci” OMIA 000263-9615

  • One copy makes a dog a carrier. In the study that found this change, every dog with DM that was tested had two copies.
    OMIA 000263-9615

    “All affected dogs tested were homozygous mutant.” OMIA 000263-9615

What to do
A DNA result isn't a diagnosis. If the way your dog walks changes, take that and the result to your vet.

Not tested, or a mix
Without a test, no one can tell how many copies your dog has. How common it is in a breed says nothing about one dog.

Which Mendelian variants matter most for Saint Bernards?

Saint Bernards tested in the Donner cohort (n=721) show a remarkably low burden of screened Mendelian variants. The variants listed above account for the confirmed carriers in the Donner cohort. None reach 2% frequency. The breed’s genetic bottleneck is real and tight: 26 of the 37 atlas dogs descend from a single 2016 founder cohort.

Cone-Rod Dystrophy (cord1-PRA/crd4)

Cone-rod dystrophy in Saint Bernards is autosomal recessive with incomplete penetrance, affecting photoreceptor function and causing progressive vision loss. The variant has an allele frequency of 0.56% among tested Saint Bernards (Donner 2023, n=720).

Testing is available. The gene implicated is RPGRIP1.

Collie Eye Anomaly (CEA)

Collie eye anomaly in Saint Bernards is autosomal recessive. It causes abnormal development of the choroid and retina, ranging from asymptomatic to vision-threatening depending on severity. The variant has an allele frequency of 0.35% among tested Saint Bernards (Donner 2023, n=721).

Testing is available. The gene is NHEJ1.

How should I test my Saint Bernard?

The allele frequencies are so low that routine screening of these variants (DM, cystinuria, cord1-PRA, CEA, prcd-PRA, and the two DCM-related variants) is a courtesy to the breed, not an urgent necessity for most owners. For breeding stock, a panel covering these six is the standard practice. The Orthopedic Foundation for Animals recommends hip and elbow screening as well, given the breed’s size.

What should I feed a Saint Bernard?

Feeding a Saint Bernard well means feeding for a breed that typically reaches 140 to 180 pounds at adulthood (AKC breed standard), grows to full size over roughly 18 to 24 months, and has a cited life expectancy of 9.3 years (McMillan 2024 / VetCompass, n=1,129). The growth rate is steep and the joint load is high.

Controlled calcium and phosphorus during growth are non-negotiable. Saint Bernard puppies undergo one of the fastest growth trajectories in the dog world. The National Research Council’s 2006 nutrient standards recommend a calcium-to-phosphorus ratio of 1.1:1 to 2:1 and an absolute calcium level of 1.2% to 1.8% of dry matter for large-breed puppies. A formulation designed for giant-breed growth, not all-life-stages, is the right choice for the first 18 months. Excess calcium during growth predisposes to developmental orthopedic disease and joint dysplasia; undershooting is equally harmful. Work with a veterinarian or board-certified veterinary nutritionist to match the formula to the pup’s growth curve.

Adult-life weight management is the single largest determinant of joint longevity and lifespan. Saint Bernards are prone to obesity, which compounds hip and elbow stress. The breed’s life expectancy, 9.3 years (McMillan 2024 / VetCompass, n=1,129), is already among the shortest of large breeds. Overweight dogs of giant breeds develop mobility problems earlier and face shorter lifespans, a pattern documented across large-breed cohorts (German et al. 2012, Vet J 192:428-434). Measure portions against the dog’s actual activity level, not the kibble bag’s guidelines. A lean body condition score (3/9 on the Purina scale, visible ribs without pressing) extends years.

Cardiac screening is essential; feeding adjustments follow veterinary findings. Saint Bernards are a giant breed with a real incidence of dilated cardiomyopathy, though the substrate shows the variants are rare (all below 0.1% allele frequency). A baseline cardiac evaluation at age 3 to 4 and periodic re-screening thereafter is a reasonable precaution for a giant breed; consult your veterinarian or the ACVIM cardiology consensus guidelines for specifics. If a vet detects a murmur or cardiomegaly, a taurine-supplemented adult formula becomes the default; discuss specific targets with a board-certified veterinary nutritionist or cardiologist. Grain-inclusive formulations with proven taurine supplementation are the conservative choice.

The cystinuria allele frequency is so low (0.97%) that diet-based stone prevention is not a breed-wide concern. If your Saint Bernard has two copies and forms stones, its vet manages them with diet and regular urinalysis. A carrier with one copy needs nothing different.

What we don’t know

The Saint Bernard cohort in the Donner study is small (37 atlas dogs, though 721 were genotyped). The founder structure is very tight (26 of 37 from a single 2016 source). We do not yet know whether this genetic narrowness masks additional recessive-disease risk in the breeding population, or whether the breed’s limited public health reporting simply reflects the fact that no large-scale prospective health survey has been conducted in Saint Bernards the way the Golden Retriever Lifetime Study was.

The breed’s life expectancy, 9.3 years (McMillan 2024 / VetCompass, n=1,129), is short for a giant breed. The causes are not yet clear from published literature. Possible contributors include cancer incidence, cardiac disease, joint failure, and founder effects, but no comprehensive epidemiological analysis has been published.

Frequently asked questions about Saint Bernards

How long do Saint Bernards live? Cited life expectancy is 9.3 years (McMillan 2024 / VetCompass, n=1,129, 95% CI 9 to 9.8), at the shorter end for giant breeds.

What is the most common genetic disease in Saint Bernards? Based on the Donner cohort (n=721), degenerative myelopathy is the most common, at 1.2% allele frequency. It is an autosomal-recessive condition that causes progressive spinal-cord degeneration in middle-aged to older dogs.

Should I do a DNA test on my Saint Bernard? For breeding stock, yes. A panel covering degenerative myelopathy, cystinuria, cone-rod dystrophy, Collie eye anomaly, and the two DCM variants is standard. The allele frequencies are low, but genetic testing helps maintain transparency in breeding decisions.

Are Saint Bernards prone to hip dysplasia? Yes. The Orthopedic Foundation for Animals reports a 25.2% hip dysplasia prevalence among Saint Bernards (OFA breed statistics, ofa.org/diseases/hip-dysplasia/). Elbow dysplasia is also present at meaningful frequency. Screening of both hips and elbows is recommended for breeding stock.

What size will my Saint Bernard puppy be at adulthood? Most Saint Bernards reach 140 to 180 pounds (AKC breed standard). Feeding for that trajectory from birth is essential.

What is the best diet for a Saint Bernard? A large-breed puppy formula with controlled calcium (1.2% to 1.8% dry matter) and a calcium-to-phosphorus ratio of 1.1:1 to 2:1 during growth. After 18 months, a high-quality adult maintenance formula with portion control for weight management. If cardiac disease is detected, taurine supplementation becomes a priority.

Do Saint Bernards need any special exercise routine? Saint Bernards are a working-origin breed but modern pets require moderate, consistent exercise appropriate to their age and condition. Puppies should not do heavy jumping or long-distance running until growth plates close (around 18 to 24 months), as premature exertion compounds dysplasia risk. Adult Saint Bernards are prone to heat intolerance due to their size and coat, so exercise in cool conditions is important.

Are Saint Bernards good with children? Saint Bernards have a long history as rescue and family dogs and are generally patient with children. Their large size means supervision with young children is always necessary to avoid accidental injury from a tail or a lean. Breed temperament is not a genetic concern in this population.

Names & origins

Other names

The Saint Bernard is also recorded as Alpine Mastiff (archaic), Bernhardiner, Saint, St. Bernard, and St. Bernhardshund.

Identified as Saint Bernard (VBO:0201160) in the Vertebrate Breed Ontology (Mullen et al. 2025, CC-BY 4.0) · registry IDs FCI 61 · iDog 476 · VeNom 19047.

For researchers Population genetics, disease models and every recorded condition Open the research detail for the Saint Bernard
What the atlas says about Saint Bernard

In the atlas, the Saint Bernard clusters consistently as Saint Bernard (100% of the 37 dogs here). Dogs here sit in a relatively sparse region of the atlas, fewer close neighbors than typical.

Life expectancy in the VetCompass cohort (McMillan 2024, n=1,129) is 9.3 years, about 1.9 years shorter than the atlas size trend predicts for the breed, one of the larger gaps in the atlas.

Genetic dimensions · CanVAS atlas

What the atlas genotypes say about Saint Bernard

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.

Dogs behind these figures
37Founders
26 from Hayward2016, 10 from Spatola, 1 from Shannon
Genetic diversity
0.31Moderate
Mean heterozygosity across the breed. Its place among 107 ranked populations is not settled: with 37 atlas dogs, resampling them moves it across 37 places.
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.

Cluster structure
Splits into two genetic sub-populations
Intra-breed RMS distance: 22.58 · likely working/show-line, regional, or kennel lineage split.
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.

Related breeds
Built from
Gave rise to
Close cousins
Distant kin · one shared founding ancestor
In the Working group
Explore the full lineage map →
VBO foundation stock (breeding records) · AKC breed group
Relatedness is documented lineage + kennel family. Genetic-ancestry distance measures diversity, not kinship, so it isn't used here.
How long they live
9.3years (life expectancy)
95% CI 9–9.8 · VetCompass, McMillan 2024, n=1,129. source
What does typical lifespan mean?

The median age dogs of the breed tend to reach.

How to read it: Higher = longer-lived. Compare to longevity-for-size to see whether it's just a size effect.

Drawn from population lifespan records; individual dogs vary widely with care, genetics, and luck.

n = 37 dogs · moderate sample · CanVAS (Brundage 2026) · Sniff Atlas
Comparative oncology

Saint Bernards are a natural model for human cancer.

Some cancers appear in Saint Bernards and in people driven by the same somatically-altered genes, cohort by cohort and cited on both sides. That makes this breed part of how we understand, and one day treat, the human disease. This is not a prediction about your dog, it is a window into the biology we share.

The dog and human osteosarcoma model →
A gift to human medicine

Saint Bernards are a natural model for human disease

Because the same genes cause the same conditions across species, the inherited conditions documented in Saint Bernards 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.

Human equivalents via OMIA → Mondo / OMIM. Model-of, not identity. The named gene is the canine locus, not a claim that a pet has the human disease.
Documented in OMIA

Every condition recorded in the Saint Bernard

Beyond the testable carriers above, OMIA's literature catalogue records 11 genetic conditions in the Saint Bernard, 9 of which have a known human equivalent. This is the documented landscape across all Saint Bernards ever studied, not a prediction for any one dog.

Online Mendelian Inheritance in Animals (OMIA); Nicholas, Tammen & Sydney Informatics Hub, DOI 10.25910/2AMR-PV70
Documented in the breed's literature is not carrier status and not a forecast for an individual dog. Human equivalents are mapped via Mondo/OMIM. Allele frequencies (above) are the separately-measured testable subset (Donner 2023).
The data behind this page

Where every number on this page came from.

This page draws on three primary data sources. Allele 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 v1.0.2 (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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References
  1. 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
  2. Brundage DM (2026). CanVAS: A Harmonized and Imputed Canine Variant Atlas. bioRxiv. doi:10.64898/2026.04.13.718238
  3. 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).
Last updated
Sources: CanVAS (Brundage 2026) · Donner 2023 · OMIA