Is My German Shepherd's Hip Score Good? Reading One OFA Grade, One FCI Letter, One BVA Number or One Distraction Index Against the Breed

A hip score is a rank inside one scheme, and no scheme except PennHIP prints the rank. Read against the breed's own registries: an OFA Fair is a normal grade, one of the three that 81.1% of 107,048 German Shepherd evaluations received; an FCI B sits roughly between the 40th and 74th percentile of Swedish Shepherds; a BVA total of 11 is the breed's exact five-year median; a distraction index of 0.35 is over the German Shepherd's 0.28 no-disease line and below the breed's published mean of 0.41 at once, which is why the report carries a percentile. The four schemes cannot be converted into one another, because the four published crosswalks disagree precisely about the second-best grade, the one you are most likely holding. And every one of these is a reading of a single film on a single day, at one or two years old; in the one cohort followed for life, 55% of dogs scored normal at two were dysplastic by the end. A score tells you where the hip stood in the line. It does not tell you how the dog will walk at nine.

The result already in her inbox#

It arrives as a PDF, or as a line in a breeder's email, or as a stamp on a pedigree from a country whose scheme you have never seen. One word, or one letter, or one number, or a decimal. Fair. B. 11. 0.35. Nothing else on the page says whether that is good, and the word chosen by the scheme does half the damage on its own: Fair reads like a C-minus to anyone who went to school, and a B reads like the grade you got when you did not quite try. Neither is what the scheme means.

We covered the breed's prevalence figures, every national table reconciled against who was allowed to count, on the data reference page, and the choice between the two American tests on the PennHIP versus OFA page. This page is for the reader holding one result, who wants to know where it sits, and what it does and does not say about the dog.

What each scheme actually hands you#

Four schemes, four kinds of output, and they are not four versions of one measurement. The first thing to settle is what your document is.

Three of the four grade the same picture, the hip-extended film, by eye. The fourth measures a different picture, taken with the hips pushed apart, with a ruler. That is the first reason a Fair and a 0.35 are not two spellings of one fact; we took the two American tests apart on their own page. The second reason is the one this page is about: even the three eye-graded schemes cut the same range of hips into bands at different places, and nobody has agreed where the cuts fall.

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Where your Shepherd's score sits among screened Shepherds#

This is the table the certificate does not carry. Each row places one scheme's output against the breed's own registry figures, and each row comes with the bias that registry was assembled under, because the bias moves the percentile.

Two things to take from the table before reading your own row. The first is that the American registry, the one most readers are holding a result from, is the one with the strongest documented incentive to leave bad films at home, so a percentile inside it flatters. A Fair among OFA-submitted Shepherds is a Fair among the Shepherds whose owners chose to send the film; the Swedish rows, where every film taken is sent, are the closest thing to a true distribution of the breed that exists, with the caveat that being filmed at all is still the owner's choice. The second is that the letter schemes report a band and the British scheme reports a point, and the point carries a piece of information the letter loses. An 11 could be 5 and 6, or 2 and 9. The BVA certificate gives the two per-hip figures, and the worse hip is the one the breeding advice, and the dog, will be judged on.

Fair, B, 11, 0.35: are they the same dog?#

Here is the part no certificate, breed club page or forum thread will tell you plainly, because the sources they draw on disagree with one another. There is no exchange rate between the schemes. There are at least four, published by people entitled to publish one, and they agree about the ends and disagree about the middle.

A widely reproduced comparison is a 2007 paper by Mark Flückiger of the Zurich dysplasia committee, and it prints two conversion tables. The author's own table places grades by the worse hip: FCI A against a BVA score of 0 to 3 and OFA Excellent or Good; FCI B against BVA 4 to 8 and OFA Good or Fair; FCI C against BVA 9 to 18 and OFA Borderline or Mild. One page later, a second table, captioned "list provided by OFA", places OFA Fair against FCI B-1 and a BVA total of 11 to 18, Borderline against B-2 and 19 to 25, and Mild against C and 26 to 35.^[4] The paper's own caveat, printed before either table: direct translation from the British numbers into a descriptive grade "is only possible if the individual score of each parameter is known."

The second is the pair of tables a breed foundation obtained from the two organisations themselves. The OFA's chief of veterinary services, G. G. Keller, collapsed the seven grades so that Excellent and Good both read A, Fair reads B1 and Borderline B2, calling it "a best fit option". The president of the FCI's scientific commission, Kirsi Sainio, read the same letters the other way: A is Excellent, B1 is Good, B2 is Borderline, and "OFA and FCI-grading cannot be compared one to one as the age, anesthesia used and the method for taking the x-ray (position of the dog etc.) may affect the end result."^[14]

The third is the BVA's own suggested conversion of its scores into FCI grades, used in a 2020 genetic study of German Shepherds: worse hip 0 to 3 is A, 4 to 8 is B, 9 to 18 is C, 19 to 30 is D, over 30 is E.^[15]

Put the four beside each other and look only at the row you are most likely holding.

Everyone agrees an Excellent is an A and a Severe is an E. The disagreement is exactly one band wide, and it is the band that holds most of the breed: whether FCI B, the "near normal" grade, is the same thing as OFA Fair, the lowest normal grade, or as OFA Good, or straddles Fair and Borderline. On a median British German Shepherd, total 11, the answer is a Fair by the OFA list and somewhere between a B and a C by the worse-hip tables, depending on how the 11 is split.

The reason is not that anyone is careless. The three eye-graded schemes are reading films of dogs at different ages, 12 months against 24, by one reader against three, with different rules on sedation, and each draws its own line. FCI B is defined as near normal and sits above the grades the 2007 paper says most countries restrict from breeding, which are moderate and severe, with "specific breeding restrictions" possible for mild;^[4] OFA Fair is the lowest grade the OFA calls normal. Those are two different lines drawn through the same stretch of hips, and nothing required them to coincide.

The 2020 study measured how far apart they actually are, in this breed. With 17,064 British and 30,909 Swedish German Shepherd records and a combined pedigree of 877,280 dogs, the genetic correlation between the British score and the Swedish FCI grade came out at 0.67.^[15] A correlation of 1 would mean the two schemes were measuring one trait. Two-thirds is a long way from that: the schemes are ranking related traits, on related dogs, not the same trait. Anyone who tells you a B "is" a Fair is choosing one of four tables and not telling you there were four.

The practical rule: convert only within a scheme, never between them. Place a Fair against the OFA's own percentages, a B against Sweden's, an 11 against the British median, an index against the percentile on the report. When a breeder's page or a pedigree carries a foreign result, ask for the original document from the original scheme and read it there.

There is one more stamp a German Shepherd owner is likely to meet. Dogs bred under the German breed club's own scheme, the SV, carry "a" ratings: a normal, a fast normal (near normal), and a noch zugelassen, which the 2007 paper translates as "tolerated for breeding" and places against FCI C. The paper's blunt observation about the largest breed clubs is worth quoting whole: they "do not comply with advice", and "the vast majority of their dogs are accepted for breeding despite the fact that a substantial percentage of dogs within the breed are dysplastic, when unbiased screening data are considered."^[4] That is a 2007 sentence about 2007 policy, and the Swiss trend on the data page shows the breed improving since. But it tells you what an a noch zugelassen stamp is: a mildly dysplastic hip that was allowed to breed.

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What a two-year score predicts for this dog#

Everything so far is about where the hip stood in the line. The question underneath it, the one the owner is really asking, is whether the dog is going to be all right, and here the honest answer is that a grade was built to answer a different question. Hip schemes exist to rank parents; the lifelong-cohort authors put it as an assumption the schemes make, that a dog normal at one or two years "will remain normal for life and is therefore considered suitable for breeding purposes."^[17] They were not built as a prognosis for the individual, and where they have been tested as one, they have done poorly.

The same hips, scored both ways. Between 1987 and 2008, 439 dogs of at least 24 months had PennHIP films and a hip-extended film in the same session, and the second was graded by the OFA. Of the 60 dogs scored Excellent, 52% had a distraction index of 0.30 or higher, the range in which osteoarthritis becomes possible; of the 223 scored Good, 82%; of the 84 scored Fair, 94%.^[16] A Fair, in other words, is a hip that looks congruent on the extended film and is loose on the distraction film almost every time. The word is accurate about the picture and silent about the laxity.

The same dogs, followed for life. Forty-eight Labrador Retrievers, paired littermates in a diet study, had a hip-extended film scored yearly by OFA criteria and a PennHIP film at two years, and their hips examined under the microscope when they died of old age. Coxofemoral subluxation on the extended film "occurred by 2 years of age and not thereafter." Then: "55% of dogs scored 'normal' at 2 years of age became radiographically dysplastic by the end of life"; 92% of the dogs scored normal at two had osteoarthritis of hip dysplasia on histopathology. The distraction index had predicted all 48 to be susceptible, and 98% had radiographic or histopathological osteoarthritis by the end.^[17] The caveats are real and we state them: these were Labradors, not Shepherds; the parents were chosen to produce 26 to 51% dysplastic offspring, so this was a colony built to express the disease; every dog had an index above 0.30; and the work was funded by and conducted at Nestlé Purina. A pet Shepherd with a tight index is not one of those 48. But the mechanism the cohort exposed is not breed-specific: the extended film at two years catches the subluxation and misses the arthritis that has not happened yet, and then the scheme stops looking.

The German Shepherd's curve. In the PennHIP database, the breed had the tightest mean index of the four large breeds studied and the highest probability of joint disease, 4.95 times the other three combined, with no joint disease observed below 0.28 against the general 0.30.^[13] The PennHIP training manual, plotting probability of osteoarthritis against index for eight breeds from 1,600 Shepherds, describes "the spatial shift to the left for the German Shepherd Dog, indicating increased risk of expressing osteoarthritis at a given distraction index compared with other dog breeds."^[7] So a 0.35 that would be unremarkable in a Labrador is over the line in this breed, and the breed percentile on the report, which compares your dog to other Shepherds, is the number that already knows this.

What a young grade is worth. The OFA's own reliability study, 2,332 dogs of four breeds including German Shepherds, compared preliminary grades given between 3 and 18 months with the final grade after 24. A preliminary Excellent was still graded normal at two years 100% of the time, a Good 97.9%, a Fair 76.9%; a preliminary Mild was still graded dysplastic 84.4% of the time. The study counted a change of status, normal to dysplastic or back, not a change of word.^[18] Fair is the least stable of the normal grades. And Borderline, the grade with no consensus, is not a diagnosis at all: the OFA's own text says to re-film in about six months and that "most dogs with this grade (over 50%) show no change in hip conformation over time and receive a normal hip rating"^[2], which the 2007 paper adds is "usually a fair hip phenotype."^[4]

Read those four findings together and the shape of a hip certificate becomes clear. It is a photograph of a hip on one day, at one or two years old, taken to decide whether that hip should be reproduced. The certificate stops being scored the day it is issued. The hip does not; the dog goes on scoring it every day, on stairs and in the car and getting up off the floor, for the next decade, and no scheme sends a second form.

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“Because your dog can't tell you how much pain he or she is in.”

If you are reading a parent's score before buying a puppy#

A different reader, holding the same document, and the arithmetic is different again.

The heritability of the hip-extended score in German Shepherds runs between 0.2 and 0.3 in the German scheme's 47,730 dogs and 0.30 for the summed British score in 13,124 Australian German Shepherds.^[19][20] That is high enough for selection to work across a population, which the Swiss trend shows, and low enough that two parents' grades are a modest predictor of one puppy's hip. The BVA's guidance is written for exactly this: choose stock "around, and ideally below" the five-year breed median, which is 11,^[6] and "where EBVs are available these should be used", with the scores of relatives taken into account.^[5] An estimated breeding value, which folds in the relatives, predicts the litter better than the parents' own two films do.

Three things a breeder's page will not volunteer. A Fair parent is a normal parent under OFA rules, and none of the three OFA pages we read today, the disease page, the grade-details page and the screening-procedures page, gives breeding advice for or against pairing two of them. An a noch zugelassen stamp is a mildly dysplastic hip that a club tolerated for breeding. And an OFA-normal pedigree was assembled from films that owners chose to submit, in a scheme whose voluntary reports, on a 2013 analysis of 760,455 hip scores, "have been severely biased against exposing dogs with problems, especially at beginning period."^[21] Ask for the siblings' and grandparents' results, not just the parents', and ask which scheme each was scored under before you compare anything.

What there is to buy for a grade, which is nothing, and the one thing that moves the grade#

A hip score is not a purchase decision and we will not pretend otherwise. Nothing you can order changes a Fair into a Good, and the reader who has just been told her three-year-old is a B does not need a bed. The two things that matter to that dog are free: know what the quiet early signs of a sore hip look like, so the next decade does not pass unread (our guide to telling whether a dog is in pain is the place to start), and keep the dog lean, which is the household variable with a controlled trial behind it.

That second one has a wrinkle that belongs on this page and not on the others where we have made the same recommendation, because it is about the grade itself. In the lifelong Labrador cohort, the OFA-criteria score "was profoundly influenced by environmental factors, such as diet restriction and age, reducing its value as a selection criterion", while "DI measurements were not influenced by dietary treatment."^[17] The earlier paper from the same colony had put a number on it: at two years, 7 of 24 dogs fed 25% less than their pair-mates were dysplastic by the OFA method, against 16 of 24 fed freely.^[22] Read that as a reader of certificates rather than as a feeder of dogs: the ration moved the word on the OFA certificate and did not move the index. A Fair on a lean dog and a Fair on a heavy one may not be the same hip, and a Good on a dog raised lean may be a looser hip than its word suggests. The index is the measurement that does not care how the dog was fed; the grade is the one that does.

We have carded a gram scale on the last three hip pages and we are carding it again for the same reason, with the same caveats: any scale in the house does the job for nothing, the clinic will weigh the dog for free once a month, and the scale tells you what you fed rather than what to feed, which still has to come from a body-condition target agreed with your vet. The 25% in the trial was 25% below an unrestricted littermate, not a number you can read off a bag.

What to do this week#

If you are holding an OFA Fair, an FCI B, or a British total around 11. Nothing needs fixing and there is nothing to appeal. File it, and file the per-hip figures if the scheme gave them. If the dog is young enough that you would act on the answer, ask about a distraction index: it is the one result that carries a breed percentile and the one that did not move with diet restriction in the lifelong cohort, and it is the measurement the JPS window is decided on in a puppy. In an adult, its use is honesty about the odds, and the resolve that comes from having a number.

If you are holding a Borderline. It is not a diagnosis. Book the re-film for six months out, today, before it becomes a thing you meant to do, and change nothing else.

If you are holding a C, a Mild, or a British score well above 11. A mildly dysplastic hip on a film is not a dog in pain, and most of these dogs are years from a symptom. What it is, is a reason to read the quiet signs early: the slower rise off the floor, the sit that drifts to one side, the walk that shortens without anyone deciding it should. Our page on whether a limp is improving is built for measuring that at home. If an insurance policy is going to be bought, buy it before this result is in a clinical record; the policy page explains why the date matters.

If you are reading a parent's score. Ask for the scheme, the per-hip figures, the siblings, and the EBV if the country publishes one. Compare within the scheme, never across it.

Whatever the word or the number, it was read from one film on one day, and it will never be updated. The delay this site exists to shorten is usually the months between the first quiet sign and the day someone names it. For the owner of a scored dog, that delay has a specific shape: a normal grade filed years ago, doing the work of a clean bill of health it was never designed to be. The certificate ranked the hip. Watching him get up is what reads it.

Sources#

1. Orthopedic Foundation for Animals. "Hip Screening Procedures." ofa.org — read 21 September 2026: "Radiographs of animals 24 months of age or older are independently evaluated by three randomly selected, board-certified veterinary radiologists"; seven conformations, "normal which includes excellent, good, or fair classifications, borderline or dysplastic which includes mild, moderate, or severe."
2. Orthopedic Foundation for Animals. "Hip Grade Details." ofa.org — read 21 September 2026: "The final hip grade is decided by a consensus of the 3 independent outside evaluations"; Borderline: "it is recommended to repeat the radiographs at a later date (usually 6 months)" and "Most dogs with this grade (over 50%) show no change in hip conformation over time and receive a normal hip rating"; Fair: "The hip joint is wider than a good hip phenotype. This is due to the ball slightly slipping out of the socket causing a minor degree of joint incongruency."
3. Orthopedic Foundation for Animals. "Hip Dysplasia." ofa.org — read 21 September 2026: the seven grade definitions; "The hip grades of excellent, good and fair are within normal limits and are given OFA numbers." No breeding recommendation by grade appears on the page.
4. Flückiger M. "Scoring radiographs for canine hip dysplasia — the big three organisations in the world." European Journal of Companion Animal Practice. 2007;17(2):135-140. PDF via icbblog.org — FCI grade definitions (Table 1); minimum ages 1 year (FCI) and over 2 years (OFA); FCI scoring "usually … by a single scrutineer per breed club or within a country"; BVA/KC nine criteria scored 0–6, 0–53 per hip, 0–106 total, read by three panellists jointly; Table 3, the author's comparison by worse joint (FCI A ↔ UK 0 / 1–3 ↔ OFA excellent / good; B ↔ 4–6 / 7–8 ↔ good / fair; C ↔ 9–12 / 13–18 ↔ borderline / mild; D ↔ over 18 ↔ moderate) including the SV column (a normal, a fast normal, a noch zugelassen, "tolerated for breeding"); Table 4, "Comparison of CHD scoring, list provided by OFA" (Excellent A-1 0–4; Good A-2 5–10; Fair B-1 11–18; Borderline B-2 19–25; Mild C 26–35; Moderate D 36–50; Severe E 51–106); "direct translation from the UK system into a descriptive grading is only possible if the individual score of each parameter is known"; the breed-club sentences quoted in the text.
5. British Veterinary Association. "Hip Dysplasia Scheme for dogs." bva.co.uk — read 21 September 2026: nine features per hip, three primary (conformation) and six secondary (arthritic response); "The minimum score for each hip is 0 and the maximum is 53, giving a range for the total score of 0 to 106"; dog "must be at least 1 year old"; advice to breed from dogs "with hip scores below or close to the published breed medians" and "Where EBVs are available these should be used."
6. British Veterinary Association. "Hip Dysplasia Scheme Breed Specific Statistics 2024." bva.co.uk (PDF) — read 21 September 2026: German Shepherd Dog row: 10,388 tested over 15 years (mean 15, median 11); 2,525 over 5 years (mean 14, minimum 0, maximum 104, median 11); 309 in 2024; "It is recommended that breeders choose breeding stock with hips scores around, and ideally below, the 5-year breed median score"; the 5-year window is 31 December 2019 to 31 December 2024.
7. Antech Imaging Services. "AIS PennHIP Training Manual," v. 2015, Chapter 2. antechimagingservices.com (PDF) — read 21 September 2026: procedure "as early as 16 weeks"; "The PennHIP report includes a distraction index for each hip, a subjective assessment of the presence and severity of osteoarthritis, and a laxity ranking of the individual dog (based on the looser of two hips) relative to other members of the breed. Because PennHIP is a continuous scale, it is not a pass/fail system"; Figure 59-7, probability of osteoarthritis by index for eight breeds from the database in November 2010 including 1,600 German Shepherds, "Note the spatial shift to the left for the German Shepherd Dog"; Figure 59-8, box plots of index in 13 breeds including 9,659 German Shepherds.
8. Oberbauer AM, Keller GG, Famula TR. "Long-term genetic selection reduced prevalence of hip and elbow dysplasia in 60 dog breeds." PLoS ONE. 2017;12(2):e0172918. doi:10.1371/journal.pone.0172918 — OFA database 1970 through April 2015, dogs 2 years or older; "Hip scores 1–3 are considered non-dysplastic"; German Shepherd Dog 107,048 hip evaluations, 18.9% dysplastic. The paper presents the Excellent proportion per breed as figures over birth year, not as a table.
9. Paster ER, LaFond E, Biery DN, Iriye A, Gregor TP, Shofer FS, Smith GK. "Estimates of prevalence of hip dysplasia in Golden Retrievers and Rottweilers and the influence of bias on published prevalence figures." Journal of the American Veterinary Medical Association. 2005;226(3):387-392. doi:10.2460/javma.2005.226.387 — of 93 dogs radiographed for OFA certification, 49 were submitted; normal-appearing films were 8.2 times as likely to be submitted.
10. Orthopedic Foundation for Animals. Disease statistics database, breed filter. ofa.org — the live per-breed split of Excellent, Good, Fair and dysplastic; renders from a query interface and is not reproduced here. On 27 August 2026 the German Shepherd Dog row read 20.4% dysplastic of 146,681 evaluated (recorded on our PennHIP versus OFA page).
11. Engdahl K, Malm Persson S, Andersson L, Ringmark S, Bjørnvad CR, Hedhammar Å, Höglund K. "Prevalence of hip and elbow dysplasia in young adult dogs in Sweden." Veterinary Record. 2026;198(12):e560-e573. doi:10.1002/vetr.70224 — Swedish Kennel Club screening 2007–2016, dogs 12–24 months; German Shepherd Dog hips 12,335 screened: A 4,876 (39.5%), B 4,305 (34.9%), C 2,175 (17.6%), D–E 979 (7.9%), C–E 25.6%. Percentile bands in the text are cumulative sums of these proportions.
12. Ohlerth S, Geiser B, Flückiger M, Geissbühler U. "Prevalence of Canine Hip Dysplasia in Switzerland Between 1995 and 2016—A Retrospective Study in 5 Common Large Breeds." Frontiers in Veterinary Science. 2019;6:378. doi:10.3389/fvets.2019.00378 — 5,326 German Shepherd Dogs: A 27.9%, B 39.7%, C 22.5%, D or E 9.9% overall; 2010–2016: A 46.5%, C 14.8%, dysplastic 18.0%.
13. Smith GK, Mayhew PD, Kapatkin AS, McKelvie PJ, Shofer FS, Gregor TP. "Evaluation of risk factors for degenerative joint disease associated with hip dysplasia in German Shepherd Dogs, Golden Retrievers, Labrador Retrievers, and Rottweilers." Journal of the American Veterinary Medical Association. 2001;219(12):1719-1724. doi:10.2460/javma.2001.219.1719 — 15,742 dogs in the PennHIP database 1983–2000; mean distraction index 0.41 in German Shepherds against 0.53, 0.48 and 0.50; 4.95-fold probability of joint disease; no joint disease below 0.28 in the breed.
14. Lagotto Romagnolo Foundation. "OFA FCI Hip Comparison." lagottofoundation.org — undated, read 21 September 2026: G. G. Keller, DVM, MS, Diplomate ACVR, Chief of Veterinary Services, OFA: Excellent and Good ↔ A, Fair ↔ B1, Borderline ↔ B2, Mild ↔ C, Moderate ↔ D, Severe ↔ E; "when collapsing a 7 point scheme (OFA) into the FCI-5 point method is it a best fit option." Kirsi Sainio, President of the Scientific Commission of FCI: A ↔ Excellent, B1 ↔ Good, B2 ↔ Borderline; "OFA and FCI-grading cannot be compared one to one as the age, anesthesia used and the method for taking the x-ray (position of the dog etc.) may affect the end result."
15. Wang S, Friedrich J, Strandberg E, Arvelius P, Wiener P. "Methods to Improve Joint Genetic Evaluation of Canine Hip Dysplasia Across BVA/KC and FCI Screening Schemes." Frontiers in Veterinary Science. 2020;7:386. doi:10.3389/fvets.2020.00386 — 17,064 UK BVA/KC and 30,909 Swedish FCI German Shepherd hip records since 2000, dogs under 12 months excluded, combined pedigree 877,280; worse-hip score converted "following a suggested conversion originally published by the BVA (0–3 = A, 4–8 = B, 9–18 = C, 19–30 = D, >30 = E)"; estimated genetic correlation between the two countries' scores 0.67.
16. Powers MY, Karbe GT, Gregor TP, McKelvie P, Culp WT, Fordyce HH, Smith GK. "Evaluation of the relationship between Orthopedic Foundation for Animals' hip joint scores and PennHIP distraction index values in dogs." Journal of the American Veterinary Medical Association. 2010;237(5):532-541. doi:10.2460/javma.237.5.532 — 439 dogs of at least 24 months, 1987–2008; distraction index of 0.30 or higher in 52% (31/60) of OFA Excellent, 82% (183/223) of Good and 94% (79/84) of Fair.
17. Smith GK, Lawler DF, Biery DN, Powers MY, Shofer F, Gregor TP, Karbe GT, McDonald-Lynch MB, Evans RH, Kealy RD. "Chronology of Hip Dysplasia Development in a Cohort of 48 Labrador Retrievers Followed for Life." Veterinary Surgery. 2012;41(1):20-33. doi:10.1111/j.1532-950X.2011.00935.x — paired littermates; yearly hip-extended films scored by OFA criteria, PennHIP at 2 years, histopathology at natural end of life; subluxation "occurred by 2 years of age and not thereafter"; "55% of dogs scored 'normal' at 2 years of age became radiographically dysplastic by the end of life (45% negative predictive value)"; 92% of dogs scored normal at 2 had histopathologic OA; DI predicted all 48 susceptible, 98% had OA by end of life; "OFA-criteria score was profoundly influenced by environmental factors, such as diet restriction and age"; "DI measurements were not influenced by dietary treatment." Research funded by and conducted at Nestlé Purina; parents selected to produce a 26–51% incidence of dysplastic offspring.
18. Corley EA, Keller GG, Lattimer JC, Ellersieck MR. "Reliability of early radiographic evaluations for canine hip dysplasia obtained from the standard ventrodorsal radiographic projection." Journal of the American Veterinary Medical Association. 1997;211(9):1142-1146. PubMed 9364228 — 2,332 dogs of four breeds; reliability of preliminary normal grades 100% (Excellent), 97.9% (Good), 76.9% (Fair); of dysplastic grades 84.4% (Mild), 97.4% (Moderate).
19. Stock KF, Klein S, Tellhelm B, Distl O. "Genetic analyses of elbow and hip dysplasia in the German shepherd dog." Journal of Animal Breeding and Genetics. 2011;128(3):219-229. doi:10.1111/j.1439-0388.2010.00901.x — 48,367 German Shepherd Dogs born 2001–2007, hip scores for 47,730; heritabilities 0.2–0.3.
20. Wilson BJ, Nicholas FW, James JW, Wade CM, Tammen I, Raadsma HW, Castle K, Thomson PC. "Heritability and phenotypic variation of canine hip dysplasia radiographic traits in a cohort of Australian German shepherd dogs." PLoS ONE. 2012;7(6):e39620. doi:10.1371/journal.pone.0039620 — 13,124 dogs scored on the nine BVA traits; summed-score heritability 0.30 ± 0.02.
21. Hou Y, Wang Y, Lu X, Zhang X, Zhao Q, Todhunter RJ, Zhang Z. "Monitoring Hip and Elbow Dysplasia Achieved Modest Genetic Improvement of 74 Dog Breeds over 40 Years in USA." PLoS ONE. 2013;8(10):e76390. doi:10.1371/journal.pone.0076390 — OFA registry 1974–2009; voluntary reports "have been severely biased against exposing dogs with problems, especially at beginning period."
22. Kealy RD, Olsson SE, Monti KL, Lawler DF, Biery DN, Helms RW, Lust G, Smith GK. "Effects of limited food consumption on the incidence of hip dysplasia in growing dogs." Journal of the American Veterinary Medical Association. 1992;201(6):857-863. doi:10.2460/javma.1992.201.06.857 — 48 Labrador Retrievers paired from six weeks, one of each pair fed 25% less; at two years, 7 of 24 restricted and 16 of 24 free-fed dogs dysplastic by the OFA method.

This page is a reading guide and does not replace veterinary advice. Whether to screen, which scheme to use, and what a result means for breeding or for a surgical decision are questions for your own vet and, where surgery is on the table, a board-certified surgeon with your dog's films on the screen.