Fifteen veterinarian x-ray experts from 10 different countries gathered on 22 January 2014 in Bargteheide, Germany, to work further on the process of harmonizing vet examinations, diagnoses and X-ray interpretation.
There is a growing need for harmonization regarding which radiographic angles to use a well for the diagnosis and how to categorize radiographic pictures of horse limbs. Harmonization in this area is a main focus, since even between countries, studbooks, and veterinarians there are differences.
The World Breeding Federation of Sport Horses (WBFSH) has initiated a working group of leading veterinarians from a number of studbooks who are now meeting on a regular basis to discuss these topics.
Minutes Meeting 22 January 2014 Bargteheide
Germany has 16 breeding associations which are difficult to harmonize among each other. Right now not all of the 16 breeding associations are harmonized but the major ones (e.g. Holsteiner, Hannoveraner, Westfalen, Oldenburger...) have found general guidelines to work with. The harmonization of the german breeding harmonization includes x-rays and clinical health examinations. The first main problem which was realized was the x-ray evaluation among the different associations. If stallions were excluded in one of them breeders tried to let the horse be approved in one of the other associations.
One major subject in Germany is the OCD-Question, while i. e. in Ireland side bones are a very often been recognized as a problem.
The German agreement about the radiographic examination includes the number, the views and the description of the x-rays. J.M. Denoix made a diagram that shows the differences between the countries. It was agreed that he sends it to us to share with the participants.
Findings which are excluded in German after the harmonization process are:
- OC/OCD in one stifle (OC meant as being more severe than a mild flattening of the trochlear ridge)
- OCD in both hocks
- fragments in more than 3 joints
In Germany the same set of x-rays is used for approval, auction and pre- purchase, because it is one event. In general pre-purchase examinations the client can decide how many x-rays and views he wants (usually 12 -14 pictures).
The opinion about x-rays of the back is that they are often not helpful because there are frequent findings on the x-rays which do not necessarily lead to problems. Here it is important to differentiate between performing horses and young stallions.
The owner has to fill out one declaration concerning surgeries and one for medication in the last 6 weeks.
Of all approved stallions blood samples for a doping analysis will be taken for storage (Holsteiner). Some random samples are being examined right away.
The common opinion is that the data for heritability of OCD is stable over the last decades. In the hock for example in the Netherlands 0,27, in Germany 0,26 - 0,3. The German selection of stallions with OCD in the hock was not as strict as in the Netherlands, where OCD in one hock led automatically to an exclusion of the stallion for approval. Nevertheless there was no change of OCD incidence in both countries yet.
The prevalence of navicular disease decreases steadily. One explanation is that the selection is nowadays towards a light sport horse constitution.
Especially for the breeding associations it is important not to select on one feature (e.g. navicular disease) but on a good sport horse. If a stallion with OCD is excluded, this might lead to the problem of losing the best horse. It is very important to evaluate the whole horse and not judge the horse on it ́s x-rays. It is also important to find an agreement between breeders and market who want the best sport horse and the veterinarians who are in charge to find problems or health risks in these horses.
Another point is not to forget the selection of the mare which is also important.
In Denmark it is possible, that an extraordinary good performing stallion (full- grown in sports career) can be accepted for approval even though he has OCD.
Another idea was to start monitoring the offsprings of the stallions with OCD. But this would take time and it is difficult to find someone who would pay the costs for the x-rays.
In Denmark they just started to register all x-rays of stallion ́s offsprings and sample them in a database. In the Netherlands they already have an offspring sample-register.
The veterinarians discuss the important clinical health issues for the examinations before approval.
Equine recurrent uveitis in most papers shows low heritability, and is therefore accepted in most warmbloods.
Conformation abnormalities: Angular limb deformation is mentioned by German veterinarians but the approval committee has to decide if it matters or not. In Germany the breeder has to declare if the foal had a surgery (i.e. periosteal lifting). The problem seems to be more the bad sales value than the later performance or heritability. Not accepted should be clubfoot because of the high heritability.
Laryngeal hemiplegia in Denmark and Germany is not accepted. In Denmark the stallion is examined via approval and if there is a sound, the horse is not accepted. In Germany the examination is a few weeks before the approval. When recognizing a sound while lunging the horse, it has to be scoped (sedated). In order to facilitate the grading in Germany the veterinarians (Holstein, Trakehner, Hannoveranian, Westfalian) use following grading system:
- 1. Complete abduction of the arytenoid cartilages possible and synchronous movement: normal
- 2. Complete abduction of the arytenoid cartilages and a asynchronous movement: acceptable
- 3. Incomplete abduction of the arytenoids cartilage and asynchronous movement: not acceptable
The first and second grade can be accepted for approval and grade 3 will be excluded. Any other causes for a sound are not important for approval if there is no other endoscopic finding. The laryngeal hemiplegia needs to be excluded because of the high heritability.
The examination of the testicles was done in different ways in Germany. For Hannover they had to be measured, for Holstein and Trakehner the vets describe the consistency, size and symmetry. In Denmark all stallions have to do a sperm test and stallions with twisted testicles are not accepted. In Germany they pass with twisted testicles, because it seems to be mostly temporary and all stallions are insured for fertility.
In Hungary the veterinarians often find melanomas, but there is not much information about the heritability. In the other countries this is not listed as a problem.
The veterinarians actualize the list of radiographic views for each country. Spain does not have a protocol at the moment, but the associations aren ́t harmonized yet and Manuel Novales Durán can just speak for the Andalusian breeders.
The second diagram, a minimum protocol is being discussed with the new participants. It is a suggestion of a minimum standard of 12 views in Europe and each country may determine more views if necessary. It should be a standard but in case of questionable findings more views should be taken for evaluation. The shoes should be taken off and the feet packed for the radiographic examination to achieve a good quality view of the navicular area. The veterinarians discuss the advantages of the different views in each standard protocol and country.
The third diagram shows the different radiographic interpretations in the countries which the veterinarians discuss.
The veterinarians discuss x-rays with questionable findings and borderline cases if they should be accepted or not.
Navicular bone: fragments at the distal margin – accepted in France, in Denmark and in Germany as well for approval.
Fetlock: Palmar/plantar fragments at the proximal border of the proximal phalanx and at the distal proximal sesamoid bone (PSB) has to be evaluated as avulsion not as OCD.
Malformation of the sagittal ridge can be found in sound horses.
Irregularity of the dorsal sagittal ridge is ok.
Irregularity at the lateral and medial margins of the proximal phalanx on the AP- view seems to be a former nutritional problem (vitamine and calcium excess)
An osteophyte at the dorso-proximal border of the metatarsus III can be evaluated as a normal finding. Osteophytes at the border of the distal intertarsal joint can cause problems more often.
Stifle: flattening or indentation at the trochlear ridge (115°) – a flattening will be accepted in most countries but an indentation should be evaluated as an OC and not pass approval. It is to discuss that OCD is a process and sometimes it is difficult to decide whether further changes in the subchondral bone will occur.
On a few x-rays it is not possible to evaluate findings clearly. The main opinion is, if it is to be questioned whether the finding could be a superimposition or OCD another x-ray with another view is required.
The Veterinarians decide to meet again in a maximum 2 year interval. The next meeting should be in November 2015 in Paris. For the next meeting each country is asked to work out further information about one joint, e.g. OCD heritability, scientific paper and practice experiences.
The grading systems should be discussed as well again.
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