The German X-Ray Classes (Röntgenklassen)
Contents
A Röntgenklasse (“x-ray class”) is the summary grade — from class I (ideal findings) to class IV (clinical significance probable) — that German veterinarians historically assigned to a horse’s purchase radiographs under the national Röntgenleitfaden. The class system was officially retired at the start of 2018 in favour of descriptive, risk-based reporting, yet its vocabulary survives throughout the European sales market: adverts still claim “TÜV I–II” or “Klasse 1–2 geröntgt”, auction conversations still reach for a grade, and buyers still ask what class a horse x-rayed. This page explains what each class meant, why the system was abandoned, and how to translate class-talk into useful questions today.
It is the focused companion to the purchase x-rays overview, which covers the standard view sets, image ownership, validity windows and auction dossiers, and to common findings decoded, which interprets the findings themselves. Here the subject is the classification: the single most influential piece of vetting shorthand the European horse trade has produced.
Where the classes came from
The Röntgenleitfaden is the German professional guideline for the radiographic part of the purchase examination (the Ankaufsuntersuchung, or AKU), issued by the German equine-medicine association GPM. For roughly two decades before 2018, its defining feature was the class system: every deviation on the films was assigned a grade, and the whole set was summarised in a class between I and IV. Formally the ladder had seven rungs — four main classes and three intermediates (I–II, II–III, III–IV) — because examiners so often found themselves between definitions.
The intention was sound: a standardised national scale, so that a report written in Warendorf meant the same thing in Munich. The effect went further. The grade compressed a full radiographic set into one number that a seller could print in an advert, a buyer could repeat by telephone and an auction could publish in a catalogue — Germany nicknamed the exercise the TÜV, after the country’s vehicle roadworthiness inspection. That compression made the classes commercially irresistible, and it is precisely what the profession later concluded was wrong with them.
What the classes meant
The formal definitions, paraphrased, with the market’s working translation:
| Class | Formal meaning | How the market read it |
|---|---|---|
| I | Ideal findings — no deviations from the norm | “Perfect x-rays”; rare, since examiners hesitated to certify perfection |
| I–II | Between ideal and normal | Clean for all practical purposes |
| II | Findings deviating from the ideal, but without expected clinical significance | The everyday “clean” standard; “TÜV I–II” territory |
| II–III | Between normal and the grey zone | Where pricing conversations began |
| III | Findings whose clinical significance is possible but not probable | The negotiation zone: discounts, use-dependent judgement |
| III–IV | Approaching probable significance | Serious discounts; many buyers withdrew |
| IV | Findings whose clinical significance is probable | Heavy discount to walk-away; often unsellable at market level |
In practice, reports graded each region and the least favourable finding governed the headline class — one reactive joint could carry an otherwise flawless horse into class III. The market then did what markets do: “class I–II” hardened into the definition of clean x-rays, sellers priced on it, auction dossiers led with it, and a class III grade could cut a horse’s value substantially regardless of what the finding actually was.
How individual findings landed was always the examiner’s judgement, but the pattern — indicative only, and variably applied — ran roughly as follows. Minor contour and shape variants, small remodelled splints and unremarkable navicular-canal variation sat in class II. An isolated small OCD fragment at a classically benign site, mild lower-hock arthrosis or narrowed spinous-process spaces without remodelling tended toward class III — possible, not probable. A fragment in a load-bearing joint, marked kissing-spine changes with bone reaction, or pronounced arthrosis read as class IV. The word “variably” is doing real work in that sentence: the same set of films could return from two competent readers with two different grades, and regularly did.
Why 2018 retired the classes
The revised guideline — issued by the GPM and effective from the start of 2018 — abolished all seven grades without replacement. The reasoning, worth any buyer’s attention because it is a free education in reading radiographic reports, identified four failures.
False precision. A school grade implies the science can rank a horse’s radiographic future on a four-point scale. It cannot: the published correlation between many findings and later clinical problems is weak, and the same image means different risks for a low-level amateur horse and a Grand Prix prospect. A single number erased exactly the distinction that matters.
Inter-reader variance. The imprecise class definitions produced honest disagreement between examiners — three intermediate classes existed because the main four could not be applied consistently. A grading system that competent professionals apply differently to identical films is not a measurement.
Displacement of the clinical exam. The classes had shifted the market’s weight from the horse to the pictures: buyers negotiated over grades while the clinical examination — which the 2018 guideline explicitly restores as the most important basis for assessing the horse — receded. Radiographs cover a small part of the finding spectrum; a grade made them look like the whole verdict.
Litigation. Vague definitions attached to large sums of money generated disputes; a horse graded II–III by one vet and III by another was a lawsuit waiting for a plaintiff. Descriptive reports that name findings serve everyone better when a sale later turns contentious, as the burden-of-proof mechanics in hidden defects and seller liability explain.
What replaced the grades is descriptive, risk-based reporting: findings matching or trivially deviating from normal anatomy need not be catalogued; deviations are described in standardised vocabulary; and the report draws one line that matters — findings demonstrably associated with a lameness risk in the published literature are flagged as risk findings, while findings whose future significance cannot reliably be assessed are stated as exactly that. The same revision enlarged the standard examination from fourteen to eighteen views. Honest uncertainty, in more detail, replaced confident single digits.
How the vocabulary survives
Guidelines change faster than languages. Nearly a decade on, the class vocabulary remains the trade’s spoken shorthand, and a buyer meets it in four places. Adverts still write “TÜV o.B.”, “Röntgenklasse 1–2” or “Klasse 2 geröntgt” — the advert decoder files these under claims that summarise a document the buyer should read instead. Older x-ray sets genuinely carry class grades, since anything filmed before 2018 was reported under the old system, and such sets still circulate as history alongside current images. Dealers and agents reach for a class in conversation because one number travels better than a paragraph — and some German vets, asked directly, will still offer an informal “that would have been a II–III” as a courtesy translation. And at auction, where dossiers are now descriptive, bidder conversation has kept the old scale alive as a private ranking.
None of this is sinister; markets compress. But a buyer should notice what the compression drops: a post-2018 report contains no class, so any class quoted for a recent set is the seller’s own summary, not the veterinarian’s finding.
Translating class-talk into questions
The working rule: treat every class claim as a pointer to a document, never as the document.
| The seller says | It actually claims | The buyer asks |
|---|---|---|
| “TÜV I–II” / “Klasse 1–2” | A report exists describing no significant findings | For the report and DICOM images; who examined, when |
| “Aktuell geröntgt, o.B.” | Current images, no remarkable findings | The same — plus the view count, since “clean” on ten views says less than on eighteen |
| “Klasse 2–3, price reflects it” | A named finding exists somewhere | Which finding, which location, what clinical correlation |
| No radiographic claim at all | Nothing — an absence worth noticing | Whether any images exist, of any date |
Then the standard protocol from the x-rays overview applies. Obtain the actual images as DICOM files and a written report that names each finding and its location. Have them re-read by a veterinarian answering to the buyer alone — interpretation varies between readers, which is the surviving kernel of truth in the whole class saga — and for a purchase abroad, that means the arrangements described in organising an international PPE and remote buying. Check the set’s age against the roughly six-month market convention for currency. And put the question to the vet in the form the 2018 reporting format was designed to answer: not “what class is this?” but what risk does this named finding carry for this horse, in the career I have described? Findings that surface from that conversation feed negotiation and the insurance file, not a grade.
The same information without classes
Other markets never adopted a grading scale, and seeing how they express the identical information is a useful check that the buyer loses nothing when the class disappears.
The Netherlands reports sales vettings descriptively — the advert formula klinisch en röntgenologisch goedgekeurd claims a passed examination, not a grade. The one Dutch structure resembling a radiographic class is the KWPN’s PROK predicate, but it is a pass-or-fail breeding screen recorded against the horse, designed for studbook selection rather than purchase pricing.
The United States has no national grading system: the examining veterinarian issues a descriptive report, buyers at higher prices commonly commission a board-certified radiologist’s second reading, and major sales operate image repositories that buyers’ vets read for themselves — description plus second opinion, the 2018 German logic arrived at independently.
The United Kingdom frames the entire examination differently: the BEVA/RCVS five-stage vetting produces an opinion on the horse’s suitability for the buyer’s stated intended use, with radiographs an optional addition informing that opinion rather than a certificate in their own right.
Three markets, one convergence: named findings, plus a professional risk opinion against a declared use. That is what a Röntgenklasse always tried to abbreviate — and what a buyer hearing class-talk today should ask to see in full. This page is general education, not veterinary advice: what a finding means for a specific horse is the examining veterinarian’s question.
Sources
- Gesellschaft für Pferdemedizin (GPM) — Röntgen-Leitfaden 2018: Leitfaden für die röntgenologische Beurteilung bei der Kaufuntersuchung, 2018. https://www.bundestieraerztekammer.de/tieraerzte/leitlinien/downloads/171020_GPM-Roentgen-Leitfaden.pdf
- Bundestierärztekammer — Röntgenleitfaden 2018 bringt einige Neuerungen (press release), 2017. https://www.bundestieraerztekammer.de/presse/pressemeldung.php?X=20171026120901
- Deutsche Reiterliche Vereinigung (FN) — Neuer Röntgenleitfaden 2018 kommt, 2017. https://www.pferd-aktuell.de/news/aktuelle-meldungen/fei---fn---dokr/neuer-roentgenleitfaden-2018-kommt
- Royal College of Veterinary Surgeons — Supporting guidance ch. 7: Equine pre-purchase examinations, 2026. https://www.rcvs.org.uk/setting-standards/advice-and-guidance/code-of-professional-conduct-for-veterinary-surgeons/supporting-guidance/equine-pre-purchase-examinations/
- British Equine Veterinary Association / RCVS — Guidance Notes on the Examination of a Horse on Behalf of a Prospective Purchaser. https://www.beva.org.uk/Portals/0/Documents/Resources/PPE%20Guidance%20Notes.pdf
Frequently asked questions
What does Röntgenklasse mean when buying a horse? A Röntgenklasse is the summary grade, from class I (ideal findings) to class IV (clinical significance probable), that German veterinarians historically assigned to a horse’s purchase radiographs under the national Röntgenleitfaden. The class system was officially retired at the start of 2018 in favour of descriptive, risk-based reporting, but the vocabulary survives widely in adverts, auction talk and buyer conversations.
What does TÜV or Klasse 1-2 geröntgt mean in a horse advert? TÜV is the colloquial German term for the radiographic part of the purchase examination, borrowed from the vehicle roadworthiness inspection. Klasse 1-2 geröntgt claims the images were graded in the historical clean zone: findings absent or deviating from the ideal without expected clinical significance. Translate it as a claim that a report exists describing no significant findings, then ask for that report and the images themselves.
Do the German x-ray classes still exist? Not officially. The revised Röntgenleitfaden issued by the German equine-medicine association GPM, effective from the start of 2018, abolished all seven grades (four main classes and three intermediates) without replacement. Reports since then describe findings in standardised vocabulary and flag those with a literature-supported lameness risk. The class vocabulary survives only as market shorthand, mostly attached to older x-ray sets or used loosely by sellers.
Was a class III or IV horse unbuyable? No, and this was one of the system’s problems. Class III meant clinical significance was possible but not probable, and many class III horses performed sound careers; class IV meant significance was probable and commanded heavy discounts. But the same finding could carry very different risks for different careers, which a single grade could not express — a key reason the classes gave way to use-specific risk assessment.
What should a buyer ask instead of the x-ray class? Three things: the images themselves as DICOM files rather than screenshots or a verbal summary; a written report naming each finding and its location; and a second reading by the buyer’s own veterinarian, framed against the intended career. The modern question is not what grade the set earned but what risk each named finding carries for this horse in the job the buyer has described.
How do other countries grade purchase x-rays? Generally they do not. Dutch sales vettings report descriptively (the KWPN’s PROK predicate is a pass-or-fail breeding screen, not a purchase grade); American practice uses descriptive reports, often with a specialist radiologist’s second reading; British practice centres on the vet’s opinion of suitability for intended use, with radiographs as an optional addition. All converge on the same information: named findings plus a risk opinion.