Breeding News

Harmonization of x-rays - diagnosis, categories etc.

With a growing need for harmonization regarding which radiographic angles to claim, the diagnosis and how to categorize radiographic pictures of horse limbs, harmonization in this area has been a main focus for the WBFSH, since even between countries, studbooks, and veterinarians there are differences in how this is dealt with.

Therefore, the WBFSH has initiated a working group of leading veterinarians from a number of studbooks and they have already made good progress. Please find below a description of the process so far along with the latest minutes from the meeting in Paris on November 12th 2015.

Update from December 2016:
The harmonization of the guidelines appears in the presentation below. Through an international and WBFSH-based number of meetings, a harmonization of the diagnosing of findings, angles, and the classification has been agreed on and the minutes from the meeting are published below.

Group photo from the meeting in Bargteheide, Hamburg, Germany on January 22nd 2014.
Group photo from the meeting in Bargteheide, Hamburg, Germany on January 22nd 2014.

Minutes of WBFSH Joint meeting on March 25th 2011 in Brussels

Harmonization of X-ray pictures and diagnosis

There is a growing need for harmonization regarding which radiographic angles to claim, the diagnosis and how to categorize radiographic pictures of horse limbs. Harmonization in this area will be hard, since even between countries, studbooks, and veterinarians there are differences in how this is dealt with.
An already existing world-wide cooperation between equine veterinarians could be involved in producing a set of regulations on the above. A Danish and a German veterinarian who are already cooperating for instance on viewing the young Danish stallions for selection, could be asked to join the working group.
If at least the studbooks in future would require the same joints and angles, it would be easier, but by now, some studbooks also require ultrasound pictures. A focus on fysically and easily measured aspects along with an agreement among leading equine vets as to what is OCD and not, etc., could be a way to start.

Minutes of WBFSH Joint meeting on July 7th- 8th 2011 in Amsterdam

X-ray harmonization

The following five veterinarians attended: Gerd Brunken and Werner Jahn (Germany), JM Denoix (France), Jimmy Saunders (Belgium) and Maureen Prendergast (Ireland). Unfortunately, the Danish vet. Johnny Sørensen was not able to participate.

The WBFSH wishes to harmonize the basis of X-rays standards between countries. It is in particular important to make the exchange of stallions easier. The focus should therefore be on stallions for breeding, more than riding horses. The WBFSH suggested the veterinarians to work with the following agenda:

1. Definition of a common protocol for the number and projections of X-rays.
2. Determination of the number of categories and description of the separate categories
3. Agreement on radiological interpretation

The veterinarians discussed the agenda for a few hours and then reported to the WBFSH joint meeting. They had agreed on item 1 and decided that the minimum of X-rays should be 12 projections. Each country could add more projections, if needed. Item 2+3 needs several more meetings, not necessarily together with the WBFSH. The veterinarians would also like to extend the group with veterinarians from the Netherlands, Denmark and Sweden etc.

The veterinarians suggested that the group could meet in connection with the examination of X-rays of stallion prior to the stallion selection in each country in order to exchange experience. It was pointed out that there can be differences in the consequences of the findings depending on the policy of the individual breeding association.

X-ray seminar in the Cirale (Normandy, France) on December 18th - 19th 2012

Introduction

Prof Denoix welcomed 6 colleagues in the Cirale (Centre d'Imagerie et de Recherche sur les Affections Locomotrices Equines) in the frame of the WBFSH X-ray Harmonization:

- Dr Werner Jahn: Expert for the Holsteiner & Trakhener Stud Books and for the German FN
- Dr Gerd Brunken: Expert for the Hannoverian Stud Book.
- Dr Johnny Sörensen: Expert for the Danish Warmblood .
- Dr Hans Schougaard: Expert for the Danish Warmblood
- Dr Malena Behring: Expert for the Swedish Warmblood
- Dr Els Raes, replacing Jimmy Saunders this time, Expert for the Bwp & Sbs

The President of he Wbfsh, Mr Jan Pedersen was represented by Dr P Hubert, vice president.
Unfortunately, Dr Maureen Prendergast from Ireland and Dr Caroline Gerdes and Chris Phillips from Rossdales could not attend.

Items

a) Item 1.

The veterinarians confirmed:

Diagram 1 established in Amsterdam showing a minimum requirement of 12 projections, each country having the possibilty to add more projections, if needed.
Diagram 2 showing the angles of projection.

The group agreed also on the necessity of quality criteria:
- Quality of the X-rays.
- Only Digital pictures (except for old horses).
- Only Dicom presentation, because certifying the identification data of the Horse (what is not the case by jpg).
- Architecture of the bone visible.
- Soft tissues visible.
- Joint spaces visible.
The sedation was considered as optionnal.

b) Item 2: Determination of the number of categories and description of the separate categories

The veterinarians agreed on the diagrams proposed by Prof Denoix in Amsterdam.
Diagram 3: 5 Grading criteria are coded in a scale from 0 (normal) to 4 (pathologic), and connected to a severity index going from 1 (benign) to 8 (severe). The addition of each finding's severity index on a horse is giving the Radio score of that horse.
This verdict is a compromise.

Ocd is predisposed skeleton responding to mechanical injuries...with possible influence of feeding.
Ocd craters or flatenings have not the same prognose on the sport career but have the same genetical signification.
Ocd being not seen in neck & back, we will never have the end of it.

The mention"OCD free" doesn't exist for a horse or a breed as long as the skeleton will not be totally checked (not only legs) for that horse or for that breed.

Diagram 4: Distribution of the horses to the radiographic score
Diagram 5: Distribution of the horses within 5 radiographic categories.

The 3 first categories showing no significant difference between these horses in their sport career longevity, they are also the basis of the health selection in stallions.
The German grading criteria are coded in a scale starting not from 0 but from 1 (normal).

This shifting between the 2 scales (French & German) could mislead and shows how important the WBFSH harmonization process is, and we could regret to have started it a few years to late.
But the German colleagues are in discussion for integration of the new knowledge about findings in their scoring & this step will take a new dimension in the frame of the harmonization process.

c) Item 3: Agreement on radiological interpretation.

Then the veterinarians examined the X-rays coming from different countries.
Joint by joint, the findings were screened with comparison on both scales:
- Foot : Navicular osteodensity is variyng according to the angle of the foot.
The higher are the heels, the more chance of navicular osteoporosis
The lower are the heels, the more pression occurs on the naviculars & the more developped are the synovitis fossae.
Only lollypops are abnormal, showing excess of pressure on the naviculars.

Fractures are not genetical selection criteria

- front fetlocks,
- hind digits,
- hocks: pigeon toed, sickle shaped hindlegs predispose to bone spavin
- stifles including the patella
- others: neck & tarsus

This screening showed that a consensus existed about the findings.

Conclusion

After two meetings on this important matter, the veterinarians (present in Amsterdam and/or Cirale) are aware to constitute a reference committee henceforth in the frame of the Wbfsh X-ray harmonization for stallions exchange between countries.

They felt usefull to meet again in december 2013, and agreed on Hambourg in Germany for hosting the next meeting.

The Breeding Associations will give now a political signification to the gradings.

The last step is to them:
- Do they focus selection on findings or not?
- Do they select more open & check the offspring (minimum of 25 offspring)?

The idea is to send a protocol to the Stud Books in order to give them the opportunity to make a position.
The veterinarians thank Prof Denoix for his hospitality and for the visit of the very updated Centre he is managing in Dozulé.