{"topic_id":"companion_species_health_canine_hip_dysplasia_dog","category":"companion-species-health","context":"---\nlicense: permission_granted\ntopic_id: companion_species_health_canine_hip_dysplasia_dog\ncategory: companion-species-health\ntitle: \"Dog (Canis lupus familiaris) — Canine hip dysplasia (hereditary; OMIA-verified species predisposition)\"\nlang: en\nsource: \"OMIA (Online Mendelian Inheritance in Animals, University of Sydney) species-specific hereditary-disorder record, saved verbatim to source_file; C1 substring-verified. Pulled 2026-08-24 from local OMIA database dump.\"\nsource_file: pdf-raw/species-health/dog_canine_hip_dysplasia_815.txt\ndate_parsed: 2026-08-24\ntokens_estimated: 3328\nverification:\n  method: substring_match\n  claims: 5\n  passed: 5\n  date: 2026-08-24\nrecovered: false\npath: companion-species-health/companion_species_health_canine_hip_dysplasia_dog/01_companion_species_health_canine_hip_dysplasia_dog.md\nsource_document: \"OMIA — Online Mendelian Inheritance in Animals (University of Sydney)\"\ncitation:\n  authority: \"OMIA — Online Mendelian Inheritance in Animals (University of Sydney)\"\n  title: \"Dog (Canis lupus familiaris) — Canine hip dysplasia (hereditary; OMIA-verified species predisposition)\"\n  url: \"https://omia.org/OMIA000473/9615/\"\n  retrieved: \"2026-08-24\"\n  ref: \"OMIA species-specific hereditary-disorder records (omia.org), derived from local OMIA database dump; dataset: https://doi.org/10.25910/2AMR-PV70\"\n  doc_type: \"academic animal-genetics database (species-specific disorder entries)\"\n  needs_review: false\n\nverification_derived:\n  method: derived_from_dataset\n  source: \"OMIA database dump (omia.xml, local); fields Gene/Variant/Article/OMIM\"\n  note: \"Structured fields (gene, variant rsID/protein change, PubMed/DOI references, OMIM cross-link) extracted from OMIA dump and presented with first-hand values; not verbatim prose.\"---\n\n# Dog (Canis lupus familiaris) — Canine hip dysplasia (hereditary; OMIA-verified species predisposition)\n\nSource: first-hand OMIA (University of Sydney) species-specific hereditary-disorder record, saved verbatim to `source_file`; every claim below is a C1 byte-substring of it.\n\n## Claims\n\n- `Species: Dog (Canis lupus familiaris)`\n- `Disorder: Canine hip dysplasia`\n- `Mode of inheritance: This disorder is a classic example of a multifactorial trait; it is definitely familial, but is equally definitely NOT due to a single gene. Heritability of liability has been estimated on many occasions. The most comprehensive review of CHD heritability published to date is by Janutta and Distl (2006) who present 105 estimates ranging from 0.00 to 0.93, based on 125,166 dogs, with an average of around 0.35. The most comprehensive large-scale analysis of CHD data is the one by Oberbauer et al. (2017) who estimated the heritability of CHD (scored according to the OFA criteria [see below] on 1,056,852 dogs representing 60 breeds) as ranging from 0.46 to 0.75, with an average of 0.57.`\n- `Control: In order to devise a sensible control strategy, it is essential to distinguish between the trait that we wish to improve (the breeding objective) and the trait that is actually measured (called the selection criterion). In the case of hip dysplasia, the breeding objective is clinical expression of hip dysplasia, i.e. lameness. However, since clinical expression is very difficult to measure, and may not be expressed at an early age, the selection criterion in most hip dysplasia control programmes is 'radiographic' hip dysplasia (RHD), which is readily assessible at an early age. The fact that RHD is assessed subjectively does not detract from its usefulness as a selection criterion. All that is required is that RHD be measured on an arbitrary scale, and that this measurement has a positive genetic correlation with clinical hip dysplasia. Although no estimates of this correlation have been made, the available evidence (e.g., Lewis et al., 2025) indicates that it is positive and sufficiently high to justify the use of RHD as the selection criterion in control programmes. The heritability is sufficiently high to justify a selection programme based on simple mass selection, i.e. selection of individuals according to their own phenotype. However, selection is more effective if the data are subjected to a proper quantitative genetic analysis using mixed models to calculate an Estimated Breeding Values (EBV) for each animal, which provides the best possible prediction (based just on phenotypic information) of the RHD score to be expected in the offspring of that animal. Three of the major scoring schemes used around the world involve evaluation of a hip-extended radiograph. Flückiger (2007) and Verhoeven et al. (2012) summarise each of these three schemes. One of these was devised for the British Veterinary Association (BVA) and the German Shepherd League (Willis, 1989, p. 165), and is now the standard BVA/KC (Kennel Club) scheme for almost all breeds in the UK, New Zealand and Australia. It involves the scoring of nine different features on each hip, as assessed from a hip-extended radiograph. For one of the nine traits (Caudal acetabular edge), the score is on a scale from 0 (ideal) to 5 (worst); for the other eight traits the score is from 0 (ideal) to 6 (worst), giving a total potential range of scores for each hip from 0 to 53, and a total dog score ranging from 0 to 106 (Dennis, 2012). With such a large range of possible scores, selection on RHD is essentially the same as selection on a continuously varying trait such as body weight; in effect, this scoring scheme has changed RHD from a threshold trait to a conventional multifactorial (quantitative trait). This provides a substantial advantage to breeders wishing to decrease the incidence and severity of hip dysplasia. A large-scale analysis of \"data from dogs of six breeds [Labrador Retriever, Golden Retriever, German Shepherd Dog, Rottweiler, Bernese Mountain Dog), and Newfoundland] scored [in the BVA/KC Hip and Elbow Dysplasia grading schemes] from 1990 to present\" by James et al. (2019) \"demonstrated evidence of improving genetic trends with respect to hip score and elbow grade in [the above] six UK registered breeds in line with phenotypic improvements and participation in screening schemes.\" The other two hip-extended schemes involve multiple thresholds rather than a continuous score. The scheme run by the Orthopedic Foundation for Animals (OFA) in the USA classifies dogs into one of seven categories: Normal (Excellent, Good, Fair), Borderline, and Dysplastic (Mild, Moderate, Severe). In a large-scale study of over 1 million OFA hip dysplasia records and over 275,000 elbow dysplasia records from 60 breeds, Oberbauer et al. (2017) \"demonstrated that there has been overall improvement in hip and elbow conformation with a reduction in EBV for disease liability, although the breeds differed in the magnitude of the response to selection.\" Leighton et al. (2019) analysed data from German Shepherd Dogs, Labrador Retrievers and Golden Retrievers within The Seeing Eye Inc. populations, in which careful and extensive selection has been conducted on a score very similar to the OFA score since 1980. With all selection decisions being under the control of a single organisation, selection in these populations was, in effect, compulsory, compared with the schemes in which selection is voluntary, being in the hands of individual breeders. As reported by Leighton et al. (2019), substantial favourable selection response was achieved: \"Among first generation puppies, 34% of 273 German Shepherd Dogs, 55% of 323 Labrador Retrievers, and 43% of 51 Golden Retrievers had an Excellent hip extended score. After 8 generations of selection, mostly based on estimated breeding values derived from the hip extended score, over 93% of 695 German Shepherd Dogs, 94% of 528 Labrador Retrievers, and 87% of 116 Golden Retrievers received an Excellent hip extended score.\" Importantly, Leighton et al. (2019) reported that \"In the latter generations of this study, hip improvement based on HES [hip-extended score] selection has practically reached an endpoint for all three breeds, that being Excellent hip phenotype. In the last generation class of each breed containing more than 100 dogs, 99% had HESC Excellent hips. When all dogs have nearly the same hip phenotype, almost no selection pressure can be applied to improve hip quality using the HES or HES EBVs.\" This result highlights the major limitation of the OFA and other similar scoring systems, which (in effect) divide a continuous variable into a small number of classes, thereby wasting lots of valuable information. If the OFA scoring system were to be changed to actually reflect the continuous underlying variable (as, in effect, the BVA/KC scoring system does), the problem highlighted by Leighton et al. (2019) would be avoided. The scheme run by the Fédération Cynologique Internationale (FCI) places dogs into one of five classes: A (Normal), B (Transitional), C (Light), D (Medium), E (Severe). See Flückiger (2007) and Verhoeven et al. (2012) for a summary of this scheme. Another major scoring scheme is PennHIP, developed by Dr Gail Smith while at the University of Pennsylvania School of Veterinary Medicine, and launched in 1993. As stated on its web site (http://info.antechimagingservices.com/pennhip/navigation/general/what-is-PennHIP.html), this scheme \"consists of three separate radiographs: the distraction view, the compression view and the hip-extended view. The distraction view and compression view are used to obtain accurate and precise measurements of joint laxity and congruity. The hip-extended view is used to obtain supplementary information regarding the existence of osteoarthritis (OA) of the hip joint\". The scheme uses a single continuous predictive parameter, namely the Distraction Index (DI), which is calculated from measurements taken on the worse (looser) of the two hips as viewed in the distraction radiograph (Smith et al., 1993, 1995). In other words, the actual PennHIP score is based on only half the available information (from just one hip rather than from both hips) from only one of three radiographs taken. This limitation of the PennHip scheme was reinforced in the review by Reagan (2017). In addition to exhibiting a disconcerting misunderstanding about the meaning of heritability, this review repeats the often-quoted claim that the heritability of DI is higher than the heritability of the OFA score, and that therefore response to selection under the PennHip scheme will be greater than selection under the OFA scheme. This claim is problematic on several counts. First, the range of DI heritabilities quoted by Reagan (2017) (0.61 to 0.83) omits an estimate of 0.50 reported by Todhunter et al. (2003); and the range of heritabilities quoted by Reagan (2017) for the OFA trait (0.22 to 0.76) is misleadingly incomplete: as mentioned in the inheritance section above, the range from the most comprehensive review of heritability estimates for OFA and comparable extended-hip traits is actually 0.00 to 0.93, with an average of around 0.35 (Janutta and Distl, 2006). And the range of extended-hip heritabilities from a recent large-scale analysis of OFA data by Oberbauer et al. (2017) is 0.46 to 0.75, with an average of 0.57. Furthermore, the range of DI heritabilities is actually based on only three published estimates of DI heritability, estimated from a total of only 3.078 dogs, whereas the 105 estimates for OFA and comparable traits reviewed by Janutta and Distl (2006) are based on 125,166 dogs; and the Oberbauer et al. (2017) range is for estimates from each of 60 breeds derived from a total of more than 1 million records (actually 1,056,852)! This comparison highlights the unfortunate reality that the exceedingly rich and valuable PennHip data set collected on presumably tens, if not hundreds, of thousands of dogs since 1993 has not yet been subjected to a published quantitative genetic analysis. It would be an immense service to the global dog breeding community if such a study were undertaken not just on the DI record from the worse hip, but on the DI of both hips and all the other invaluable data collected from all three PennHip radiographs. Second, even if the heritability of DI is higher in a particular breed, this does not automatically mean that selection on DI will be more effective, because response to selection is not determined solely by heritability. As if to highlight the unprecedented potential of the PennHIP data set for genetic analysis, Smith (2018) emphasised the existence of \"a non-biased database of genetic information\" as the first \"essential element\" of the PennHIP scheme. It is to be hoped that this exceedingly rich resource will soon be subjected to the genetic analysis it so richly deserves, which will so greatly inform all schemes for the control of canine hip dysplasia. A small step along this path was taken by Leighton et al. (2019) who estimated heritability of DI (presumably just one hip) from nearly 9,548 dogs bred within The Seeing Eye Inc. (TSE) population, to be 0.60, 0.66 and 0.59 for German Shepherd Dogs, Labrador Retrievers, and Golden Retrievers, respectively. Comparable estimates of heritability of an OFA-like hip-extended score were 0.76, 0.72, and 0.41, respectively. Similar types of estimates from the entire PennHIP data set (including all observations recorded on both hips in all three radiographs) are awaited with great interest. In a most unusual paper, Kim et al. (2022) reported using prime editing (PE) to replace an unfavourable allele with a favourable allele at an intergenic quantitative trait SNP locus that makes an unknown (but presumably very small) contribution to the genetic variation in liability to hip dysplasia (the QTL having been reported only in a patent application, with neither the breed nor the number of dogs being mentioned in the paper), and then using the genetically-modified fibroblasts to create two puppies with the favourable QTL allele by somatic cell nuclear transfer, concluding that this illustrates a \"platform to correct genetic defects in dogs\". Neither of the puppies was evaluated for hip dysplasia. Despite hip dysplasia being a classical quantitative trait, the study was claimed to be the first \"that eliminate[s] the cause of HD by directly controlling the causative gene\".`\n- `Gen test: As noted in the Mapping section above, the results of Distl and Marschall (2007) were incorporated into a genotypic test for CHD patented by Distl and Marschall (EP 2 123 777 B1; filed in 2009). The test involves calculation of a \"numerical breeding value\" as the weighted sum of information from up to 17 polymorphic markers, to be used in predicting the CHD phenotype of individual dogs and predicting the average CHD phenotype of the progeny of particular matings. Noting that the markers used in this patented test appear never to have been validated in published papers, Manz et al. (2017) reported a validation test of the \"numerical breeding value\" as a predictor of individual phenotype, concluding that \"the genetic test patented by Distl et al. (2009) is unsuitable for individual CHD risk assessment\". It is important to note that Manz et al. (2017) did not assess the value of the patented test as a predictor of average CHD phenotype of the progeny of particular animals or particular matings.`\n## Associated gene(s)\nDerived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.\n- OMIA entry symbol: CHD (no structured Phene_Gene link)\n\n## Evidence (references)\nDerived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.\n- 1963. A new look at developmental subluxation and dislocation : Hip dysplasia in the dog. Journal of Small Animal Practice — OMIA Phene_Article / Article\n- 1966. Canine hip dysplasia and how to control it. Orthopedic Foundation for Animals, Incorporated, and Hip Dysplasia Control Registry, Philadelphia — OMIA Phene_Article / Article\n- 1972. Canine hip dysplasia: relative risk by sex, size, and breed, and comparative aspects. J Am Vet Med Assoc — PubMed:PMID5010615 — OMIA Phene_Article / Article\n- 1979. The inheritance of canine hip dysplasia. Modern Veterinary Practice — PubMed:PMID514247 — OMIA Phene_Article / Article\n- 1973. Hip dysplasia in military dogs. Journal of the American Veterinary Medical Association — OMIA Phene_Article / Article\n- 1975. Skeletal development of Greyhounds, German Shepherd dogs and their crossbreed offspring: an investigation with special reference to hip dysplasia. Acta Radiologica Supplementum — PubMed:PMID1066037 — OMIA Phene_Article / Article\n- 1975. Plasma levels of estradiol and plasma protein binding sex steriods in dogs. An investigation with special reference to development of hip dysplasia in growing individuals. Acta Radiologica Supplementum — PubMed:PMID1066030 — OMIA Phene_Article / Article\n- 1965. Hormone induced hip dysplasia in dogs. Journal of Small Animal Practice — OMIA Phene_Article / Article\n- 1962. The control of canine hip dysplasia in the Scandinavian countries. Advanced Small Animal Practice — OMIA Phene_Article / Article\n- 1963. The radiographic diagnosis of hip dysplasia in the dog. Veterinary Record — OMIA Phene_Article / Article\n- 1980. German Shepherd dog hip survey. Veterinary Record — PubMed:PMID7467112 — OMIA Phene_Article / Article\n- 1965. [Hip dysplasia in dogs]. Nordisk Veterinaermedicin — OMIA Phene_Article / Article\n- (665 additional references in OMIA)\n\n## Comparative medicine (human OMIM)\nDerived from OMIA database dump (omia.xml, local); structured field, not verbatim prose. First-hand values below are verbatim substrings of the topic's pdf-raw/omia/<phene_id>.txt source file.\n- OMIM:142669 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:142700 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:244510 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:265050 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n- OMIM:615612 (type: trait) — OMIA Group_OMIM (via OMIA_ID)\n","sources":["companion-species-health — Dog (Canis lupus familiaris) — Canine hip dysplasia (hereditary; OMIA-verified species predisposition)"],"source":{"authority":"companion-species-health","title":"Dog (Canis lupus familiaris) — Canine hip dysplasia (hereditary; OMIA-verified species predisposition)","url":"https://pubmed.ncbi.nlm.nih.gov/5010615/","retrieved":"","ref":"PMID 5010615","doc_type":"official source","source_document":"","verification_file":""},"source_document":"","source_file":"","trust":{"authority_tier":"ungraded","fidelity":"verbatim","license":null,"display_grade":"pending"},"tokens_estimated":3549,"generated_at":null,"tip":"Use /api/v1/topics to discover more topics. /api/v1/nutrient for precise single-point queries. /api/v1/cross_compare for 2-3 standard comparisons."}