Chesapeake Bay Retriever
The most carried tested variant is Degenerative Myelopathy, in 25% of 138 Chesapeake Bay Retrievers tested (Donner 2023), then Progressive Rod-Cone Degeneration (9.6%) and Exercise-Induced Collapse (7.6%). Only 13 dogs stand behind the atlas figures here, so little is known yet.
Also known as CBR, Chesapeake, and Chessie.
What genetic diseases do Chesapeake Bay Retrievers carry?
From a panel of 250 Mendelian-disease variants screened in 1,054,293 dogs (Donner et al. 2023), Chesapeake Bay Retrievers carry 6 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.
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.
FGF4what this gene does
FGF4 influences leg length by affecting bone growth, leading to shorter legs in certain breeds.
For your dog: If your dog is from a breed known to carry this gene, it's worth discussing spinal health with your vet, but being a carrier doesn’t guarantee problems.
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.
DNM1what this gene does
DNM1 is a gene that helps nerve cells communicate properly by managing how they send signals during muscle activity.
For your dog: If your dog belongs to one of the breeds known to carry this gene variant, it's worth discussing EIC with your vet, especially if your dog is very active or shows signs of weakness during exercise.
TUBB1what this gene does
TUBB1 is a gene that helps make the building blocks of platelets, which are tiny blood cells important for clotting. It plays a key role in keeping platelet size and number normal.
For your dog: If your dog is from one of the breeds known to carry TUBB1 variants, it’s worth mentioning to your vet, especially before surgeries or if you notice unusual bleeding.
NPHS1what this gene does
NPHS1 is a gene important for kidney function, helping to keep proteins in the blood where they belong.
For your dog: If your dog’s breed is on the list, it’s worth asking your vet about NPHS1 to understand any risks and keep an eye on kidney health.
What these results mean for a Chesapeake Bay Retriever
25.4% of Chesapeake Bay Retrievers in the Donner 2023 cohort carried it (n=138).
- DM is a loss of function in the spinal cord that begins in adulthood and progresses to paralysis of the back legs. There is no treatment that stops 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 variant mean at risk, not affected. Some dogs with two copies never show signs.
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 the variant, every affected dog tested had two copies.
OMIA 000263-9615
“All affected dogs tested were homozygous mutant.” OMIA 000263-9615
What to do
A DNA result is not a diagnosis. Take the result, and any change in how the dog walks, to a veterinarian.
No test, or a mix
Without a test nobody can say how many copies a dog has. A breed's carrier frequency describes the breed, not this dog.
1.1% of Chesapeake Bay Retrievers in the Donner 2023 cohort carried it (n=137).
- Two extra copies of a growth gene, FGF4, shape dog legs and spines. The one on chromosome 12 is the one tied to disc disease; the one on chromosome 18 shortens legs.
OMIA 000157-9615
“Two FGF4 retrogenes (FGF4L1 on chromosome 18 and FGF4L2 on chromosome 12) have been identified to cause dwarfism across many dog breeds.” OMIA 000157-9615
“Brown et al. (2017) reported that an FGF4 retrogene insertion in chromosome CFA12” OMIA 000157-9615
- Carrying it raises risk. It does not say which dog will have a disc problem. In Dachshunds researchers found the test is not a valid risk indicator on its own.
OMIA 000157-9615
“the FGF4 retrogene insertion on CFA12 is not a valid risk indicator on its own” OMIA 000157-9615
What to do
Ask your veterinarian what a carrier result changes for your dog. What lowers risk in a carrier is not established in the sources this page draws on.
No test, or a mix
Without a test nobody can say whether a dog carries it. Leg length alone does not tell you: the disc-disease copy and the short-leg copy are different insertions.
Other names
The Chesapeake Bay Retriever is also recorded as CBR, Chesapeake, and Chessie.
Identified as Chesapeake Bay Retriever (VBO:0200326) in the Vertebrate Breed Ontology (Mullen et al. 2025, CC-BY 4.0) · registry IDs FCI 263 · iDog 70 · VeNom 14605.
For researchers Population genetics, disease models and every recorded condition Open the research detail for the Chesapeake Bay Retriever
In the atlas, the Chesapeake Bay Retriever clusters consistently as Chesapeake Bay Retriever (100% of the 13 dogs here). Dogs here sit in a relatively sparse region of the atlas, fewer close neighbors than typical.
High breed predictability score (2.32), individual dogs of this breed reliably cluster together genetically. Only 13 dogs of this breed in the atlas, modestly sampled.
What the atlas genotypes say about Chesapeake Bay Retriever
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=13) 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=13) 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.
Chesapeake Bay Retrievers are a natural model for human disease
Because the same genes cause the same conditions across species, the inherited conditions documented in Chesapeake Bay Retrievers 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.
- amyotrophic lateral sclerosis type 1, modeled by the breed's Degenerative myelopathy via SOD1, the same underlying biology.
- OMIM:608245, modeled by the breed's Curly coat , the same underlying biology.
- epidermolysis bullosa simplex due to plakophilin deficiency, modeled by the breed's Ectodermal dysplasia/skin fragility syndrome, PKP1-related , the same underlying biology.
- developmental and epileptic encephalopathy, 31A, modeled by the breed's Exercise-induced collapse , the same underlying biology.
- mucopolysaccharidosis type 6, modeled by the breed's Mucopolysaccharidosis VI , the same underlying biology.
- retinitis pigmentosa 36, modeled by the breed's Progressive rod-cone degeneration, PRCD-related , the same underlying biology.
Every condition recorded in the Chesapeake Bay Retriever
Beyond the testable carriers above, OMIA's literature catalogue records 7 genetic conditions in the Chesapeake Bay Retriever, 6 of which have a known human equivalent. This is the documented landscape across all Chesapeake Bay Retrievers ever studied, not a prediction for any one dog.
- Degenerative myelopathy Autosomal recessiveHuman equivalent: amyotrophic lateral sclerosis type 1
- Curly coat AutosomalHuman equivalent: OMIM:608245
- Ectodermal dysplasia/skin fragility syndrome, PKP1-related Autosomal recessiveHuman equivalent: epidermolysis bullosa simplex due to plakophilin deficiency
- Exercise-induced collapse Autosomal recessiveHuman equivalent: developmental and epileptic encephalopathy, 31A
- Mucopolysaccharidosis VI Autosomal recessiveHuman equivalent: mucopolysaccharidosis type 6
- Progressive rod-cone degeneration, PRCD-related Autosomal recessiveHuman equivalent: retinitis pigmentosa 36
- Intervertebral disc disease Autosomal dominant
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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- 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).