Canada - Canadian Hanoverian Society (CHS) posted three documents on their website recently: 1) German Radiology Introduction, 2) German Radiology Guidelines and 3) Standard X-ray Views. As explained in the Guidelines document, these documents describe the system developed in Germany in 1991 and implemented in 1993 to classify equine radiographs.
The German system includes standardized pre-purchase examinations, 16 standardized x-ray views of the legs and feet plus two views of the spine, as shown in the third document. With regards to the interpretation of radiography a system was developed which characterizes x-rays as being Class I-II-III-IV.
In developing this system for classifying radiography, the key was to base the system on evidence based medicine. That is, the German Hanoverian Verband undertook longitudinal studies which showed the probability of a radiographic finding actually resulting in a lameness or unsoundness. This clinically based analysis took much of the subjectivity out of the interpretation of radiography. The description of this grading system is found in the Guidelines document on page five. It is summarized below:
- Class I: Without specific abnormal radiological findings and findings categorized as anatomical variations. (Ideal condition)
- Class II: Findings mildly deviating from ideal condition; appearance of clinical issues estimated less than 3% in an indefinite time. (Norm condition)
- Class III: Findings deviating from norm condition; appearance of clinical issues estimated in 5 – 20% in an indefinite time. (Acceptance condition)
- Class IV: Findings severely deviating from norm condition; appearance of clinical issues likely (more than 50%) (Risk condition)
Intermediate classes: The use of intermediate classes I-II, II-III and III-IV results from different examiners and their experience and interpretation of the distinctiveness of findings. Further sub-division is not allowed. The difference in percentage in between classes II, III and IV corresponds to division in intermediate classes II-III and III-IV.
Anyone who is buying or selling horses in our global economy is encouraged to review all of this information, as understanding German pre-purchase examinations is useful. Breeders may also want to ask their veterinary professionals if this system should potentially be adopted by the equine veterinary community in their country as well. A link to complete information about the x-ray grading system is now available on the web at http://www.canadianhanoverians.com/programs/german-system-for-grading