Chondrodystrophy and Intervertebral Disc Disease Risk (CDDY)
Chondrodystrophy and Intervertebral Disc Disease Risk (CDDY). Autosomal dominant. Observed in 113 of 266 breeds tested in the Sniff Atlas, with measured carrier frequencies drawn from 241,530 dogs (Donner 2023). Per-dog phenotype outcome depends on penetrance, modifiers, and environment; the carrier frequencies below describe variant prevalence, not disease incidence.
- OMIA identifier
- OMIA:000157-9615
- Inheritance
- Autosomal dominant
- Linked gene
- CDDY
- Source dataset
- Sniff Atlas v1.0.1 / DOI
Top 25 well-sampled breeds (n ≥ 50)
Maximum carrier frequency per breed across variants in the Donner 2023 cohort, with Wilson 95% confidence intervals. The list below is split into well-sampled breeds (n ≥ 50 tested) and small-sample breeds (n < 50, where the Wilson CI typically spans more than 20 percentage points and frequencies should not be compared directly to the well-sampled entries). Frequencies are population-level, not per-litter or per-line.
| Breed | Carrier frequency | n tested |
|---|---|---|
| Dachshund Miniature Longhaired | 99.5% | 213 |
| Cavalier King Charles Spaniel | 99.0% | 2,232 |
| Cocker Spaniel | 98.5% | 1,870 |
| Dachshund Miniature Shorthaired | 95.1% | 583 |
| English Cocker Spaniel | 94.0% | 579 |
| Cardigan Welsh Corgi | 93.5% | 124 |
| Beagle | 93.5% | 5,245 |
| French Bulldog | 87.9% | 13,062 |
| Poodle Toy | 81.9% | 94 |
| Pembroke Welsh Corgi | 80.4% | 4,351 |
| Spanish Water Dog | 71.5% | 93 |
| Papillon | 68.3% | 197 |
| Basset Hound | 67.5% | 982 |
| Poodle Miniature | 63.4% | 3,544 |
| Boykin Spaniel | 59.1% | 154 |
| Kooikerhondje | 56.1% | 197 |
| Pekingese | 41.6% | 238 |
| Chinese Crested | 31.8% | 201 |
| Nova Scotia Duck Tolling Retriever | 29.4% | 63 |
| Coton De Tulear | 28.4% | 104 |
| Chinook | 24.4% | 80 |
| English Springer Spaniel | 23.6% | 749 |
| Danish Swedish Farmdog | 20.8% | 60 |
| Bichon Frise | 20.8% | 1,059 |
| Biewer Terrier | 20.1% | 184 |
Top 25 of 80 well-sampled breeds with at least one observed carrier shown.
▸ Also observed in 33 small-sample breeds (n < 50)
Frequencies in this section are statistical estimates with wide Wilson 95% confidence intervals (typically >20 percentage points). Treat these as "carriers observed but the true population frequency is not yet measurable" rather than as comparable to the well-sampled entries above.
| Breed | Estimate | n tested |
|---|---|---|
| Bavarian Mountain Hound | 100.0% | 8 |
| Clumber Spaniel | 100.0% | 12 |
| Continental Toy Spaniel | 100.0% | 8 |
| Dachshund Longhaired | 100.0% | 1 |
| Dachshund Shorthaired | 100.0% | 6 |
| Dachshund Wirehaired | 100.0% | 4 |
| Dandie Dinmont Terrier | 100.0% | 1 |
| English Toy Spaniel | 100.0% | 2 |
| Field Spaniel | 100.0% | 28 |
| Poodle Medium | 100.0% | 1 |
| Skye Terrier | 100.0% | 4 |
| Sussex Spaniel | 100.0% | 3 |
| Welsh Springer Spaniel | 91.7% | 12 |
| American Water Spaniel | 83.3% | 6 |
| Polish Lowland Sheepdog | 83.3% | 3 |
| Entlebucher Mountain Dog | 77.3% | 11 |
| Sealyham Terrier | 75.0% | 4 |
| Stabyhoun | 66.7% | 27 |
| Alpine Dachsbracke | 50.0% | 1 |
| Schapendoes | 47.8% | 45 |
| Drever | 25.0% | 4 |
| Lowchen | 25.0% | 4 |
| Puli | 25.0% | 12 |
| Bedlington Terrier | 22.7% | 11 |
| German Spitz | 16.7% | 3 |
| Pyrenean Shepherd | 15.5% | 29 |
| Tibetan Spaniel | 11.5% | 39 |
| Bolognese | 10.0% | 5 |
| Russian Toy | 10.0% | 5 |
| Russian Tsvetnaya Bolonka | 10.0% | 15 |
| Munsterlander Small | 6.7% | 15 |
| German Hunting Terrier | 3.8% | 13 |
| Silky Terrier | 2.0% | 28 |
153 additional breeds in the Donner 2023 cohort were tested but showed no carriers.
Scope
This record carries the breed-level carrier frequencies from the Donner 2023 cohort. Penetrance data (the fraction of at-risk dogs that develop the phenotype) is not yet quantified for this disease in the Sniff Atlas v1.0.1. The OMIA entry is the authoritative reference for the clinical phenotype, inheritance pattern, and gene assignment.
Predicted disease relevance at the per-dog level is UNPROVEN. Carrier frequency is measured; phenotype outcome depends on penetrance, environment, and modifier loci. Consult a veterinarian for clinical interpretation.
Citations
If you use this record in published work, cite the Sniff Atlas (the published dataset that carries the breed-level carrier frequencies) and the upstream sources:
- Sniff Atlas v1.0.1 for the per-breed carrier frequencies:
Gehring, M. (2026). Sniff Atlas v1.0.1. Zenodo. https://doi.org/10.5281/zenodo.20566358. CC-BY 4.0.
- OMIA for the disease definition, inheritance, and gene assignment:
Nicholas, F. W., & Tammen, I. (2024). OMIA. Sydney Informatics Hub, The University of Sydney. https://doi.org/10.25910/2AMR-PV70. Entry: OMIA:000157-9615.
- Donner et al. 2023 for the breed × variant carrier-frequency cohort:
Donner, J., et al. (2023). PLOS Genetics, 19(3), e1010651. https://doi.org/10.1371/journal.pgen.1010651.
Full citation formats (BibTeX, RIS, CITATION.cff) at sniff.world/cite.
Related
- Gene page: CDDY — per-breed allele frequencies + biological notes + cross-references.
- Sniff Atlas v1.0.1 — the source dataset for these frequencies.
- Browse breeds — per-breed Mendelian profiles, including this disease in context.
- OMIA entry OMIA:000157-9615 — authoritative clinical reference.