HWSD testing Statistics

The Veterinary Genetics Laboratory (VGL) from UC Davis which is conducting all of the HWSD testing worldwide, has provided the Connemara Pony Research Group with a report on the numbers of ponies that have been tested for the HWSD mutation to date.

The reason for doing this is to help the CPRG to continue to help educate and disseminate up-to-date information to breeders.

The information from VGL is raw data only.  As with any statistics it is the analysis performed on the numbers which begins to paint the bigger picture.

The first message to understand is how the numbers are initially collected and how the table is constructed.    Also it must be noted that the ponies being sampled and tested are not 'random' samples which skews the results.

VGL states the following:
 "Attached are the summary stats by country of HWSD tests since we started offering the test at the end of August 2014. Percentage of carriers and affected were calculated only if more than 10 horses were tested per country. The carrier frequency in the VGL’s data is coming out higher than the value found in Dr. Bannasch’s research. However, keep in mind that we are using raw data from testing, which includes related individuals. Our estimates are not based on a random sample of unrelated horses and obviously overestimate the frequency of carriers and affected. With time, you’ll notice that the values will settle around the actual frequencies."

The full table from VGL is listed at the end of this page.  
This raw data  has to be adjusted and analysed in order to gain a truer picture of the situation in each country. 
VGL does not have any background information on the make up of individual populations of ponies in various parts of the world.  Country of residence does not always equate to country of origin. Using a combination of information of country of origin combined with country of residence a different picture emerges.

For example:

New Zealand is listed as having tested 21 ponies with 16 N/N and 5 N/HWSD.  However what is not obvious from the table below is that all five of the N/HWSD ponies are ponies imported from Australia. However another seven N/N ponies listed under NZ are also recent Australia imports. Another mare was imported to NZ from the UK; bred in Ireland by a French stallion, her imported in-utero colt is also in the NZ tested list.

Thus if the numbers are adjusted to acknowledge this, then the Australian/New Zealand  figures will look like this:

                            N/N    N/HWSD   HWSD/HWSD   Grand total    %age Carriers
Australia                  69           14                  1                          84                 17.9%
New Zealand          4             0                  0                            4                    0%

Similarly Australia has an N/N  colt  and an N/N filly listed which are both bred in Germany (these have been extracted from the numbers in the table above).

Canada lists four non Canadian bred stallions: one N/N from Germany, one N/N from USA, one N/N from Ireland and one N/HWSD from Ireland.

France has one N/N stallion from Great Britain.

Germany has one N/N stallion from Sweden, one N/N stallion from Ireland.

Six stallions bred and resident in Northern Ireland are listed under Great Britain.

New Zealand has listed one N/N colt of  German, Irish and French breeding but bred by a UK breeder.

USA has three Irish imports listed.

This breakdown is to demonstrate just how closely interlinked individual populations of  Connemara ponies are, across the world.  This becomes even more apparent when considering mares and fillies.

Looking purely at the country statistics from what is known from the results sent to  CPRG for positing on the HWSD tested ponies results page distribution of  ponies outside their listed country:

Australia and New Zealand tabled above.

Canada - stallions 3 imports as mentioned  above.  Mares 4/11 imported: 3 Great Britain, 1 Ireland

Switzerland - no notifications made to CPRG

Germany - 2/12 stallions as above; mares 0/11 imported

Denmark - stallions 0/6; mares 0/15 imported

France - both ponies are British bred, French residents.

Great Britain - one N/HWSD stallion from Ireland and one N/N bred in GB + the six stallions from Northern Ireland plus three mares also.
Thus GB when adjusted ONLY for the Northern Ireland situation, would look like: 53 - 9 from Northern Ireland + 2 from France = 46

          N/N     N/HWSD   N/HWSD  Total  %age Carrier
GB      40             5                  1         46              13.0%

Ireland:    8/10 of the ponies on the VGL table come from two owner/breeders.  These are on the CPRG page.  3/8 recorded are mares.  1/3 mares is N/HWSD; 1/5 stallions is N/HWSD.

Sweden: 25 ponies are on the blog list of which five are N/HWSD or HWSD/HWSD.  Even with the restricted numbers of notifications made to CPRG the %age carrier rate is still 20%.  

USA has the highest number of tested ponies to date.  Of those listed on the CPRG list, 19 are mares, 7 of which are direct imports (4 ex Ireland) or born to imported ponies in the USA (3).  3/19 mares are N/HWSD and 0/19 HWSD/HWSD.   Stallions 3/11 are imported.  1/11 is N/HWSD

Conclusion:  The uptake of the HWSD test by Irish owners and breeders based purely on population levels of the Connemara pony in each country, is very worrying.  The assumption is that this poor response is due to a very low awareness of the HWSD issue among the wider population.  The same situation is assumed for France and Great Britain.

France, which is the second largest producer of Connemara ponies in the world demonstrates an even lower uptake than Ireland - as the two ponies tested and listed are of  British breeding.

Great Britain is the third largest producer of Connemara ponies in the world; it too has significantly low uptake of the HWSD test.

Indeed Australia and the USA each have both tested more ponies than Ireland, France and Great Britain COMBINED!

For the most part the people who read this blog are already the more educated about HWSD among the breeders of Connemara ponies worldwide.  What each and everyone of you should consider doing, is to spread the message to those less well aware of the HWSD problem - and the solution afforded to breeders - by the availability of the  VGL test.

HWSD DNA Testing Statistics -September/October 2014
Country	N/N	N/HWSD	HWSD/HWSD	Grand Total	% of Carriers	% of Affected
Australia	64	9	1	74	12.2	1.4
Canada	15	6	1	22	27.3	4.5
Switzerland	3			3
Germany	25	7	0	32	21.9	0.0
Denmark	25	18	0	43	41.9	0.0
France	2			2
Great Britain	45	7	1	53	13.2	1.9
Ireland	10	2	1	13	15.4	7.7
The Netherlands		1		1
New Zealand	16	5		21	23.8	0.0
Sweden	27	9	2	38	23.7	5.3
United States	77	18	3	98	18.4	3.1
Grand Total	309	82	9	400	20.5	2.25
Test Result	Disease Status
N/N	Normal
N/HWSD	Carrier
HWSD/HWSD	Affected

Exciting News!!!!

The Connemara Pony Research Group is very proud to be able to announce that Dr Carrie Finno will be giving a public presentation on the results of the HWSS research at a meeting in Clifden on 19th August 2014.

The meeting venue is

Alcock and Brown Hotel

Vickers Function Room

The Town Square

Clifden.

1.30pm

Tuesday 19 August 2014

Dr. Carrie Finno received her DVM from the University of Minnesota (UMN) in 2004. She completed an internship in large animal medicine and surgery at UMN in 2005 and then went on to complete a 3-year residency in large animal internal medicine at the University of California, Davis (UCD), culminating in board-certification in the American College of Veterinary Internal Medicine. Dr. Finno elected to pursue a career in equine genetic research and obtained her PhD under the guidance of Dr. Danika Bannasch in 2012 from UCD. She then moved back to UMN and completed a 1-year post-doctorate fellowship with Drs. Stephanie Valberg and Jim Mickelson. Dr. Finno is currently an assistant professor at UMN. Dr. Finno's research is focused on equine genetic diseases, including Hoof Wall Separation Syndrome (HWSS) and equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (NAD/EDM), equine shivers, myofibrillar myopathy and immune-mediated myositis. In conjunction with the equine studies, she is researching the interaction of vitamin E and neural development, using a well-established mouse model.

After the conclusion of the presentation by Dr Finno, the Connemara Pony Research Group is equally delighted to be able announce a presentation by Ray Knightley.   Ray will be addressing the practical shoeing and hoof care issues associated with the HWSS affected hoof.

Ray Knightley grew up in Suffolk, Great Britain where he rode until aged 14. In 1987 Ray was living in Germany where he made the decision to train as a farrier. His farrier career now spans 26 years. Ray is a registered State farrier and a certified Euro farrier. He specialises in the area of remedial hoof care. As such Ray has become one of the 'go to' people in Europe for ponies affected by hoof wall separation syndrome (HWSS). He is presently working on developing new techniques which, it is hoped, will provide better quality of life for HWSS affected ponies. Ray brings to this meeting extensive experience in in caring for HWSS affected feet.

The Connemara Pony Research Group extends to all  interested persons, a cordial invitation to attend this meeting.

The Town Square, ClifdenThe Town Square, ClifdenThe Town Square, Clifden

The Town Square, Clifden

A Gentle Reminder

Clifden Show week is beginning on Sunday.  This is a time when much purchasing of Connemara Ponies has been the norm. The genetic test for HWSS will not be available before the end of the  year, so any pony buyers will still need to use visual criteria to assess whether a pony is HWSS affected or not; there is no way of physically assessing carrier status.

So here are a few suggestions for onsite assessment:

• Only consider young stock and/or breeding ponies presented without shoes and without hoof black. 
• Be extremely wary of ponies which are shod and not in work, especially youngstock.
• Do not accept any reasons/excuses about the farrier 'trimming the feet too short the last time he/she was out'.  Feet that are too short is a 'red flag'.
• Any chipping or peeling away of the outer hoof wall is a red flag.
• Pick up the feet yourself and have a look at the structure of the hoof wall between the white line and the outer hoof wall (see photo below).
• Look at the environment the ponies are living in. Boggy conditions masks the issue.
• Hoof black can be used to hide the use of hoof fillers - shod and hoof blacked 'red flag'.

For those purchasing from a distance (ie not personal inspection or through an agent) ask for not only conformation photos and videos, but close up pictures of feet - unshod and not blacked, and taken with the pony standing on concrete.

Here is a picture which demonstrates that the splitting occurs within in the structures of the hoof wall and not at the white line.  This photograph comes from a Swedish HWSS site with many good quality photographs of HWSS feet.  Even with short and newly trimmed feet (a prime method used to attempt to disguise HWSS), any sign of fissures should be classed as a 'red flag'.  Normal feet do not do this.

Another important factor to consider is the genetic inheritance of the pony/ies you may wish to buy. The higher the level of inbreeding, the higher the chances are of ponies carrying recessive genes.

Checkout An Analysis of the Sire Lines Represented in the 2013 CPBS Class 1 Stallion List if you want to found out just how dire the inbreeding issue is.

HWSS research has been officially presented to the world.

The team from Bannasch Laboratory were involved  in the recent 10th International Equine Genome Mapping Workshop  held  10-13 July 2013 at the Biotechnology Centre of Azores from the University of Azores. 

The First International Equine Gene Mapping Workshop sponsored by the Dorothy Russell Havemeyer Foundation (DRHF) was conducted in 1995 in Lexington, Kentucky. Since then, a series of horse genome workshops were conducted by the DRHF every two years (San Diego, California; 1997; Uppsala, Sweden; 1999; Brisbane, Australia; 2001; Kreuger Park, South Africa; 2003; Newbridge, Ireland; 2005; Tahoe City, California; 2007; Ickworth, Suffolk, United Kingdom; 2009; Chaska, Minnesota; 2011).

Over 200 scientists from 20 countries around the world have been participating in these workshops, sharing ideas and resources, collaborating and creating a common genomics framework.

The Bannasch submission is as follows:

10th Dorothy Russell Havemeyer Foundation International Equine Genome Mapping Workshop Abstract

A successful genome wide association for Connemara Hoof Wall Separation Syndrome using the equine Illumina 74K beadchip

Danika Bannasch, Carrie Finno, Carlynn Stevens, Amy Young, Sheila Ramsay

A syndrome has been described in Connemara foals characterized by severe separation of the hoof wall during the first year of life.  Clinical signs of HWSS occur when the weight-bearing borders of the hoof wall break away from the underlying structure, leaving the pony to bear weight on the sole of the hoof and unfit for riding.  Initial pedigree research has revealed a likely hereditary component to the disease with an apparent autosomal recessive mode of inheritance.   DNA samples, pedigrees and photographs were collected from Connemara ponies from around the world.  Within a year, 15 affected individuals and 315 controls were sampled.  Twelve cases and 24 controls were genotyped on the Illumina Equine 74K beadchip.  Based on our results, 12 affected and 24 unaffected cases provided significant power to identify a strong, genome-wide significant, candidate region of association (p raw 6.9 X 10^-11, p genome 2.6 X 10^-5).  Three additional affected foals and 5 obligate carriers were subsequently genotyped.  A region of homozygosity of 1.8 Mb was identified in all 15 affected foals consistent with an autosomal recessive mode of inheritance. Next generation sequence data from affected ponies and controls across the region will be analyzed for mutations and the results reported at the meeting.



The take home message from the information in the above abstract is that:

• There is NO DOUBT WHATSOEVER that HWSS is genetic in origin.  
• There is NO WAY that the above abstract would have been accepted for this workshop if the work being presented  was not proven beyond all doubt.
• HWSS is NOT the result of 'mineral imbalance', any other environmental challenge or lack of care of the part of owners of affected ponies.
• HWSS is the result of mating two ponies who carry a genetic mutation.

Denial that the cause of this condition is genetic is not going to make the problem disappear; indeed based on present trends the incidence of HWSS in the Connemara pony population is set to increase. 
A population genetics study presently underway, indicates that this is especially so in Ireland; a direct result of overuse of certain stallions both historically and in the present.

Guest Post by Tom Ryan FWCF on his experience with treating an HWSS affected pony.

This paper has recently been published in Forge Magazine and is republished here with kind permission from Mr Ryan http://www.equinehoof.co.uk/hwss.php

Hoof wall separation syndrome in Connemara ponies

Tom Ryan FWCF

The first time I saw pony Liam (name changed) was just after my client had bought him. I could see that he had slightly broken up hooves but thinking like most farriers would, I expected his hooves would improve under my charge. Unfortunately, this was not to be the case and as the winter progressed his hooves gradually deteriorated and by April 2010 the stratum externum was breaking away from the stratum medium, not just in the area around the nails but also around the toe of the hoof, an area that normally stays intact when hooves break up.

Photograph 1:  Liam's broken hoof in May 2010

As all four hooves were badly affected and thinking that a bacterial infection was causing the problem I decided to ask the help of the client's vet and together we took biopsies from the affected areas of Liam’s hoof wall. The results came back as normal, no abnormal bacteria associated with breaking hooves were found in the hoof.

Photograph 2:  Broken hoof removed and hoof poulticed with iodine

We decided that the entire areas of broken hoof should be removed but doing this to all four hooves at once was out of the question as it would make the pony very lame. Instead we decided to treat one hoof per week, in this way if we encountered problems it would be with only one foot. So each week all the broken hoof from one foot was removed and for the next twenty four hours the hoof was poulticed with iodine to ensure the hoof was sterile.

Photograph 3:  Kerckheart Aluminium shoe glued to repaired hoof

The hoof was rebuilt with glue then an aluminum shoe was glued to the repaired hoof, blue children's modeling dough was used on the inner border of his shoe to prevent the glue or shoe pressing onto the sole of his foot.  This was time consuming and expensive but worked well. For the next few months the glued on shoes were replaced as they started to become loose or were lost altogether, Liam was comfortable in the shoes and they didn’t cause him any problems.

Photograph 4: All hooves repaired

I noticed his hoof reacted slightly differently to the glue, in that the surface of stratum medium adhered less well to the glue, something I had not observed in other types of broken hooves. I have experienced cases of breaking hoof walls and seedy toe in other breeds both in everyday practice and as a referral farrier at an equine veterinary practice and I can safely say that Liam’s feet were different, although at the time I wasn’t sure quite how, it certainly was not a case of severe seedy toe.

When the wall had re-grown down to the ground surface, I could still see that his hoof was still not normal but tried again using nailed shoes, unfortunately his hooves soon started to deteriorate again. In discussion with the client it was decided to try Liam barefoot as an alternative solution to the problem but Liam soon became very uncomfortable and foot sore, as all his weight was being carried by his sole, as the hoof wall was crumbling away, we realised that this was not going to solve his problem and went back to gluing his shoes.

Liam had been bought for showing but as his feet were repaired with glue and the rules for showing do not allow filled or rebuilt hooves, he could not be shown. Considering that the only way of keeping him sound was with rebuilt hooves and glued shoes, meant his hooves were going to be a perpetual and very costly problem. After a lot of soul searching, the owner in discussion with her vet decided he would have to be put down.

It was eighteen months later at a Farriers Focus Day, that a farrier who has produced a horseshoe for broken hooves called GluShu[ii] first mentioned hoof wall separation syndrome in Connemara ponies to me. Some quick research on the internet[iii] revealed that there did seem to be an ongoing hoof wall problem within the Connemara population which some were calling ‘Hoof Wall Separation Syndrome‘(HWSS). Gauging what proportions of Connemara's have had problems or how severely it has affected them was difficult to establish, certainly some severe cases have eventually resulted in euthanasia.

Some contributors reported an apparent absence of lipids in HWSS affected hooves, a type of fat normally found in hoof, its function is thought to provide protection to the hoof structure by repelling excess moisture. Reading the comments of others about HWSS, I knew that this was what I had been dealing with eighteen months earlier.

Current thinking is that HWSS is a congenital genetic problem, the genes thought to be responsible are said to be recessive within an autosomal chromosome, autosomal chromosomes are not responsible for deciding the sex of the animal and therefore both males and females can carry the defective gene. Both parents must be carriers of the defective recessive gene in order to produce a chance of a foal with affected hooves. The possible outcomes are; a 1:4 chance that the foal will have HWSS, a 2:4 chance of a foal with good hooves but still a carrier of the defective gene and a 1:4 chance of producing a foal which is not a carrier and has good hooves.

Diagram 1:  Possible outcome if both parents are HWSS carriers. 

These chances are random and any outcome is possible for each foal born.

If one parent is a HWSS carrier and the other is not, then there will be a 2:4 chance of the foal being a carrier but it will not have HWSS hooves.

Diagram 2: Possible outcome if one parent is a carrier

The genome for the horse was sequenced for the first time in 2007, opening the opportunity to isolate which genes may be involved in HWSS. Currently research into HWSS is being carried out by Dr. Carrie Finno, DVM, PhD at University of California Davis and is focused on identifying the genes which are associated with the production of keratin, the protein which is used to produce horn and hair. DNA samples of both normal and affected animals are currently being collected and compared. The goal of this research will be the ability to identify carriers of HWSS with a simple blood test. So they can be isolated and excluded from any future breeding program (* editor's note). Until then it will only be when an affected foal with HWSS is born that it will alert the breeder that its parents are both carries of HWSS. As this may not be the first foal from this dam and sire, previous foals may have already been produced and unknowingly sold on, as there were no indicators at that time there was a genetic problem.

When only a few ponies were carriers the chances of both parents being affected must have been small, the odd foal with poor quality hooves would have been seen as a random occurrence of bad luck. Other foals would have been born as carriers with good hooves, in this insidious way HWSS has secretly crept into the population and as the ponies have moved around the world, so has HWSS. Today cases have been reported in many countries including UK, Ireland, Sweden, New Zealand and the USA.

From the one case that I have experienced, Liam's problems were of a greater magnitude than any broken hoof I had met before. The only solution to avoid future cases of HWSS will come from revised breeding practices which acknowledge the underlying genetic causes. If the first-class reputation of the Connemara is to be upheld, then both breeders and individuals will have to address this problem in an open and honest way.

First published in the Connemara Chronicle Vol 40-2013, page 183

Anatomy notes

The hoof wall is comprised of tubules of keratin which grow downward from the Coronary band. Distribution or the density of the horn tubules reduces through the three main zones of the hoof wall, the stratum externum, stratum medium and stratum internum. The greatest density of horn tubules is in stratum externum where on the surface of the hoof wall they are slightly flattened to become oval, which is thought to help retain moisture. The stratum medium forms the bulk of the hoof wall while the inner stratum internum has the lowest number of horn tubules and forms the laminal interface with the dermal tissues, it is usually un-pigmented and can be seen as a white line on darker coloured hooves

Diagram 3, Anatomy of hoof wall

Between the horn tubules is inter-tubular horn which binds the horn tubules together, this has intermediate filaments which are laterally orientated fibres which help to bind the horn tubules together and resist cracking.

The outer stratum externum is more rigid than the more flexible stratum medium, while the stratum internum is the softest, this gradient of reducing stiffness helps the hoof capsule transfer energy smoothly between the wall and the dermis and also allows the hoof capsule to expand in shape under loading and return back to it's original shape when the load is removed. Transfer of weight from the skeletal structures is primarily from distal phalanx (pedal bone) via the hoof wall to the ground surface, the solar surface can only support a small proportion of the total weight of the horse before it causes pain.

---

Footnotes:
[i] Jameg ShoeGlu, Jameg Horseshoes, Barnby Moor Stables, Kennel Drive, Barnby Moor, Retford, Notts., DN22 8QU

[ii] GluShu, https://www.facebook.com/glushu

[iii] Google "Hoof wall separation syndrome in Connemara ponies"

* Editor's note.  Removing carrier ponies from the breeding population is not recommended as this will further reduce an already truncated genepool; the test will identify carriers.  This information will help breeders to choose non-carrier mates and therefore prevent the production of any further affected ponies.

The relevance of the Fell Pony Syndrome Research to HWSS

The situation with HWSS in presently facing the breeders of Connemara Ponies is very similar to that which The Fell Pony breeders are faced with and which they have dealt with in a positive, constructive and successful manner.   The united approach to find cause of FIS  is an example that the Connemara Pony breeding community could well do to follow.  The whole of the latest research paper has been reprinted below because it has become obvious that people are not aware of how relevant this work is.  The blog stats tell us whether people outclick to the posted links; not one outclick has been made to this paper.

The overall population numbers are different between the Fell Pony situation described here and that of the Connemara Pony situation but the level of penetrance of the relevant mutations within in each of these  populations is very similar.  Table 1 at the end of the paper  makes for very interesting reading.

April 13, 2013 | Veterinary Record
Foal immunodeficiency syndrome: carrier testing has markedly reduced disease incidence

S. D. Carter, L. Y. Fox-Clipsham, R. Christley, J. Swinburne

Foal immunodeficiency syndrome (FIS), a fatal autosomal recessive disease found in three breeds of horses, was first reported (in the Fell pony) in 1996, and it soon became apparent that significant numbers of syndrome foals were being born each year. In each FIS case, the foals are clinically normal at birth, but start to weaken at 2–8 weeks (Scholes and others 1998) as they develop profound anaemia (Dixon and others 2000) and do not have the ability to produce their own antibodies (Thomas and others 2005), due to the almost total lack of B lymphocytes in the circulation or tissues (Thomas and others 2003), but with apparently normal levels of functional T lymphocytes (Bell and others 2001). The outcome is persistent opportunistic infections with no effective treatment; euthanasia is the preferred option. FIS has also been reported in Fell ponies in The Netherlands (Butler and others 2006), Germany (May and others 2011) and USa (Gardner and others 2006). In 2009, we confirmed a case of FIS in a Dales pony foal (Fox-Clipsham and others 2009).

The search for the genetic lesion thus became paramount, as the carrier parents were clinically normal, and it was feared that there could be high carrier rates in breeding Fell and Dales ponies. In 2009, we identified a single nucleotide polymorphism (SNP) in a sodium transporter (SlC5a3) which was completely associated with FIS and was homozygous in FIS foals and heterozygous in FIS carriers (Fox-Clipsham and others 2011a). The SNP is a functional alteration in an exon within the SlC5a3 gene, and within three months, we developed and launched a diagnostic test (available at http://www.animaldnadiagnostics.co.uk) based on PCR and sequencing to identify FIS carriers and early syndrome foals. This was made available to all equine owners and can be performed simply on pulled hair samples, removing the need for blood sampling.

The acquisition of the FIS test meant that we could identify carriers and make recommendations concerning the possible outcomes of specific breeding combinations, for instance, a carrier breeding with a normal pony, or two carriers breeding together. We regularly met with Fell and Dales pony owners to explain how they should use the FIS test to avoid producing a syndrome foal, and stressed the need to use the FIS test to avoid carrier-carrier matings. Concerns about depletion of the gene pool in pony breeds were soon quelled once it was explained that they could still safely use carrier ponies to breed with normal ponies. Indeed, it was pointed out that owners and breeders actually needed to widen their use of stallions to reduce the numbers of FIS foals and to preserve the gene pool.In the first year of testing, our fears were confirmed when the FIS carrier rates were shown to be 39 per cent in breeding Fell ponies and 18 per cent in breeding Dales ponies. Broadening the testing to other at-risk breeds (known to crossbreed with Fell and Dales ponies), showed that 1 per cent of a coloured pony population were carriers (Fox-Clipsham and others 2011b). There may be other breeds containing FIS carriers; only further population testing will confirm or deny this possibility.

The next key question was how effective the carrier test would be in reducing the numbers of FIS foals being born in subsequent years. There have now been two breeding seasons (2011 and 2012) prior to which the 

owners could avail themselves of the test and avoid carrier-carrier matings. The test findings (Table 1) provide considerable hope for the future.The FIS carrier rate in breeding adult Fell and Dales ponies varies over the three years of testing, but this variation was statistically significant (X2(2df) p=0.3, and Fisher’s Exact Test p=0.6, respectively). 

Importantly, there was a lower number of FIS-positive (diseased) Fell pony foals in 2011 and 2012 (although this only approached statistical significance (X2(2df) p=0.1, X2for trend (1df) p=0.08) and no FIS 

cases in Dales ponies in 2011 or 2012. Obviously, the datasets may be skewed because of the animals selected for testing, which may introduce some bias. However, as many carriers will have been identified previously from breeding records, there is no reason to suppose that FIS-positive breeding stock would be preferentially submitted. It is clear that the owners and breeders have taken the advice we provided about avoiding carrier-carrier matings, and that this has led to a major reduction in the number of syndrome foals born in the last two year. Although the definitive figures are not available, the total  number of breeding Fell ponies that have been FIS tested in the last three years (n=1171) comprise a large proportion of the breeding population, and the testing has been done to guide breeding strategies. By the same measure, the 284 Dales ponies tested represent a large part of  the breeding population of that breed.

Predictably, our breeding recommendations to use carrier-clear matings have not had a rapid impact on the large numbers of FIS carriers in the breeding populations of both breeds. Reducing carrier numbers will either take much longer using the current breeding approach, or a change in breeding strategy to avoid breeding from carriers at all. With the carrier rate so high in the Fell ponies, such a restrictive recommendation would probably be unacceptable to many  breeders, and would risk depleting the gene pool. On the other hand,  the breeders who choose carrier-clear matings will need to test their offspring to see if their foal is a carrier. The results are consistent with uptake of the FIS carrier test by the owners of at-risk ponies, and suggest that they have also taken our advice about breeding strategies to reduce the numbers of FIS-positive foals. This is a significant and swift impact of modern genomic technologies in clinical veterinary medicine, and is a healthy indicator of veterinary scientists and animal breeders working well together to improve animal welfare.

TABLE 1: Foal immunodeficiency syndrome (FIS)-positive test results in Fell and Dales ponies (adults and foals) (N/A=not applicable)

Year	Number tested	Normal (%)	FIS Carriers (%)	FIS Diseased (%)
(A) Fell ponies
Adults        2010	565	290 (51)	275 (49)	N/A
2011	179	103 (58)	76 (42)	N/A
2012	106	60 (57)	46 (43)	N/A
Foals          2010	142	72 (51)	58 (41)	12 (8)
2011	108	60 (56)	39 (36)	1 (1)
2012	71	32 (45)	38 (54)	1 (1)
(B) Dales Ponies
Adults 2010	180	158 (88)	22 (12)	N/A
2011	53	44 (83)	9 (17)	N/A
2012	36	32 (89)	4 (11)	N/A
Foals 2010	10	9 (90)	0 (0)	1 (10)
2011	4	3 (75)	1 (25)	0 (0)
2012	1	1 (100)	0 (0)	0 (0)

References
BELL, S. C., SAVIDGE, C., TAYLOR, P., KNOTTENBElT, D. C. & CARTER, S. D.
(2001) an immunodeficiency in Fell ponies: a preliminary study into cellular responses.
Equine Veterinary Journal 33, 687–692
BUTLER, C. M., WESTERMANN, C. M., KOEMAN, J. P. & SLOET VAN
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S. D. Carter, BSc, PhD, FRCPath
L.Y. Fox-Clipsham, BSc, PhD
R. Christley, BVSc, MVCS, PhD, 
DipECVPH, MRCVS
Department of Infection Biology,
Department of Epidemiology and
Population Health,
Institute of Infection and Global Health,
School of Veterinary Science, University
of Liverpool, Liverpool, UK
L. Y. Fox-Clipsham, BSc, PhD
Centre for Preventative Medicine,
Animal Health Trust, Newmarket, UK
J. Swinburne, BSc, PhD
Animal DNA Diagnostics Ltd,
William James House, Cowley Road,
Cambridge CB4 0WX, UK
E-mail for correspondence:
scarter@liv.ac.uk
Provenance: Not commissioned;
externally peer reviewed
Accepted February 14, 2013

Breaking News - HWSS is Official

It is Official!!

Because of the close relationship between the HWSS Research Group and the Bannasch Laboratory, UC Davis, we have been aware for sometime of the progress that has been made, and now we can share this publicly.

The very existence of HWSS and that it is of genetic orign of it has been questioned by many people throughout the Connemara Pony breeding world. Those who have not seen or personally experienced the condition are reluctant to accept that such a serious problem could be lurking within their beloved breed. Understandably the recurring call has been the need for scientific proof that this is not simply an environmental or management issue, but a genetic one. Now because of the dedication of a number of breeders and individuals throughout the world, we have that proof! UC Davis has released the following information into the public domain.

Here is the link to UC Davis

While this may only be the first official statement regarding research into HWSS, we believe that now is the time for an open acknowledgement that there is a cause for concern, but that there is a way out of the situation.

The ICCPS Annual General Meeting is coming up, as is the Technical Meeting. With so many delegates from breed societies around the world present for these, the research group group sincerely hopes that the UC Davis release on HWSS is enough scientific proof to acknowledge the condition, and start a constructive discussion on the issue.

For further research to continue, UC Davis needs the help of Connemara Pony owners and breeders worldwide. They need more samples from ponies, and the sooner they get them, the sooner we will have a test for the condition. The ICCPS are in a unique position to facilitate this. An education campaign to the daughter breed societies would rapidly add to UC Davis' collection of samples. Additionally, breed societies could vastly aid breeders and owners by coordinating the collection and shipment of blood samples to UC Davis. What a huge pro-active and positive step for the breed that would be!

The Connemara Pony community needs to start talking now about how to deal with the problem when a test is commercially available. There will be a time lag between the research phase being completed and when testing becoming commercial available, but that should not stop us from calmly, and rationally, discussing how this issue will be managed to the betterment of the breed.

We are not the only breed society to have faced such issues - both the Fell Pony breeders and the New Forest Pony Breeders have faced similar problems over the genetic issues in their respective breeds. And like the conditions in the above breeds, we do not believe that HWSS will be limited to just the Connemara Pony - this research will likely benefit horses worldwide.

We know the test is coming; let us as a cohesive community be positive and ready. Let the Connemara Pony community worldwide be ready and waiting to embrace the new technology as soon as it becomes available.

GET TALKING – KEEP POSITIVE AND EVERYONE WILL BENEFIT