We are not alone in dealing with evolving genetic disease....

One of the members of the research group posted this Myotonia in New Forest Ponies onto the group noticeboard, with the additional comment that all Dutch stallions are being tested and that the Swedish breeders are following suit.  Myotonia is a much more 'dramatic', scary to see disease, than that of HWSS; any readers who have seen the videos of the 'fainting goats' on youtube will understand just how dramatic and the implicationsfor survival are, for a horse or pony.

The New Forest pony, like the Connemara Pony has a reducing genepool.  As genepools condense the rising incidence of homozygosity results in a concomitant increase in the emergence of  previously unexhibited genetic defects.

On the HWSS research, we await the results of further DNA research on a specific area of the genome.  While this is happening the scientists at UC Davis are also working to extract the mRNA from the hooves of affected ponies.  This work is to try and establish which proteins are being coded for in which part of the hoof.  Once again it is a waiting game.

Sent us an email and not had a response??

The research group has over the past two months been contacted by several people from various parts of the world with notifications of new cases of HWSS.  Replies have been sent (in some cases with suggestions on management issues) to every query made to the group.   None of these people have subsequently made a reply or made further contact.   As the research group uses a gmail account it is possible that our replies have been automatically filed into a recipient's spam folder.   Please, if you have emailed the research group and not had a reply, please a) check your spam folder and b) email the group again and let us know that you have not received a reply to your intial email.  A reply will have definitely been returned within 24 hours of receipt of the original enquiry.  

Thank you

Thought for the day

"Entrenched belief is never altered by the facts".   

So true, so true; strongly held beliefs, however nonfactual they may be, rarely (if ever) are changed as the result of being exposed to the facts.  It is human nature to cling to what one believes in, for to challenge such beliefs can cause psychological harm in susceptible individuals.  

Sometimes it is considered more expedient to just accept what one is told, without challenging the status quo or the teller/s of the tale.  After all challenging one's beliefs requires introspection into many facets of the life one leads and that is way too scary for many people.

There is now much mis-information being spread 'out there' over the HWSS research.  Where people or organisations have a history of  distributing mis-information, do not expect them to be truthful in what they tell you with regards to their involvement in and support for the HWSS research project.  It was to be expected but still regretable; anything which challenges groups or individuals which exposes them to the risk of having their authority undermined, invariably results in shooting the messenger/s whilst at the same time trying to gain control over the message being delivered.  

To re-iterate once again the Connemara Pony Research Group is made up from a group of individuals who have been working together for just over one year now to get the scientific evidence to support:

1. That there is a developmental problem in the hooves of some Connemara ponies, and,
2. that this condition has a genetic cause
3. Both of these points have now been incontrovertibly proven. As regular readers of this blog will be aware the laboratory is now awaiting the data analysis from the further series of arrays which have narrowed down the area of the genome, that needs to be studied in greater detail.

The Connemara Pony Research Group is not aligned with any breed society in anyway.  The research has been independently funded by donations sent directly to the Centre for Equine Health at the University of California (Davis) by many groups and individuals.  The research at the Bannasch Laboratory (UC Davis)  has received support, both moral and financial, from societies in North America and Northern Ireland only and the group publically acknowledges our thanks to them.

Interestingly enough, when the blog author went to attribute "Entrenched belief is never altered by the facts" researches failed to find an historical context in which this was used.   Perusal of various hard copy books of quotations to no avail and thence having to resort to google (and the ubiquitous wikipedia) linked this homily only to the authorship of one Dick Francis in his novel 'Straight'.  One has to wonder from whence he learnt this very salient truth, or whether he came to this conclusion himself  and just used it as a one-liner in his book.  Either way, the truth revealed by this statement is real.

For any of the blog readers 'out there' who are not acquainted with the novels of Dick Francis then dip your toes in the water.  Rip snorting good yarns based loosely around National Hunt Racing in the UK.  Of course they are formulaeic and I swear the heroes must all have 'superman' embroidered on their underpants as they always succeed in righting wrongs against terrible odds, but they are good reads.

Thought for the day

• "All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident." - Arthur Schopenhauer (1788-1860)
  
  
• "First they ignore you, then they laugh at you, then they fight you, then you win." - Mahatma Gandhi (1869-1948)

Good news, bad news and interesting news

Good news update: blood samples from a further five HWSS affected ponies have been processed by the Bannasch Laboratory.  The analysis from these arrays is not yet complete, however early indications are that the areas of significance on the genome will be greatly reduced.  Instead of having a 'scattershot' approach to the molecular search, the specific area/s of interest are now being pinpointed.  This work cannot be hurried; we all need to await the outcome with grace and patience.

Bad news update: not the type one ever wishes to report.  The group has been notified that two HWSS affected fillies have recently been euthanased; both were profound cases of  HWSS.  These fillies were euthanased on humane grounds after advice from the owner's veterinarian and farrier.  The fillies had both been under the care of the care of these professionals since they were 3 months old.   

The veterinarian (under request from the owner) performed a post-mortem on both ponies.  This report, plus various body tissue samples and the legs from each pony were sent to the Centre for Equine Health at UC Davis for in-depth analysis.  

Let us hope that the lives of these two fillies will not have been in vain and that through the generosity of their owner in sending samples and body parts for pathology, will help successive generations of the breed.  The condolences of the research group members go out to this owner on the loss of these ponies.

Interesting news update.  This is interesting news from the academic and research perspective but probably will be seen more as a bad news post for the Connemara pony community at large.

Notification to the research group of the first clinical case of HWSS, has just this week, come in from yet another new, country.  The research group was already aware that HWSS was in this genepool but only because of the ponies which have been exported from this location that have gone on to produce HWSS offspring in other countries.   

For example, to date the only clinical case of HWSS in New Zealand is in a imported in utero from this country but, born in New Zealand, pony.  To say the least, this was a surprise to all at the time.  It also has to be noted that this in-foal mare was imported to New Zealand well before existance of the HWSS condition was being acknowledged in the wider Connemara pony population. 

What is extremely interesting from the pedigree research perspective is that in each of these  ponies from this new country, looking at their four generation pedigrees they have nothing in common with each other.  It is only when one is able to look at extended pedigrees that the probable lines of descent become apparant.  

The hypothesis behind the transmission of HWSS, as you are now all well aware, is that it is a simple recessive progression; it can pass through many generations without it ever being expressed.  To date there are (to the members of the research group) well known and obvious patterns of inheritance which appear in affected HWSS ponies.  For the most part these are 'close-up' in the pedigrees of affected ponies and quite obvious within a 4 generation pedigree.  However with two of the 'new' carriers and the one recently notified HWSS affected pony, the already known lines of descent do not appear until  6-7 generations back in the pedigrees.  

This indicates that HWSS came into this 'new'  country  with the early imports of the 1960's and 1970's and that the condition was already widely spread within the Connemara populations from Ireland and the UK.  

With the contraction of the genepool towards a more homozygous state (as is happening with the Connemara breed worldwide) then statistically one expects to see a rise in HWSS affected ponies in this particular country.

Other news: Blood samples from clinically affected HWSS ponies have recently been sent to the Bannasch laboratory from Denmark, Germany and Sweden.  Thank you to the pony owners who at their own expense had their ponies inspected, identified and blood sampled by a veterinary professional, provided the high definition photographs of the hooves and then also paid the shipping costs to the Bannasch Laboratory, UC Davis.   Sending biological samples between countries is a very involved, precise and expensive process.  Thank you to those people.

New Zealand breeders have sent over a consignment of  blood and hair samples from 39 ponies.  This shipment included the one HWSS case, the dam of this case and a normal half sibling.   

New Zealand is in a very interesting position genetically.  The ponies in this country are for the most part even more closely related to each other than seen elsewhere in the world.  This is the result of geographic isolation and the prohibitive cost of importation.  The genepool still includes breeding stock whose parents were from the first wave of imports into the country in the 1970's.   The large number of blood samples sent from New Zealand is to provide a pool of ponies that are expected to to be free of HWSS carrier status, which can then be used as 'controls' in developing the future diagnostic test.  Only time will tell whether this is in fact a true reflection of the genetic status of the Connemara pony in New Zealand.

 

On January 19th  posted on this blog was, Want to know more about HWSS? Here the opportunity is given to any interested parties to book a presentation by a local representative of the Connemara Pony Research Group. 

The blog entry commences with:

"The research on HWSS has more depth to it than what is shown in this blog.  Only the basics have been put on the internet because the internet is not a secure medium.  Anyone can lift  files off the net and use these for what ever they choose; although unlikely, people with an 'agenda' could be tempted to use such information to their own advantage and not for the greater good which is the aim of this research group."

What has to be realised is that scientific research is moving at an awesome pace - what is correct in January is superseded with new knowledge and information by March.  The presentation material contains more in depth and recent information than does the blog; see the paragraph in italics above as to why this is so.

It always pays to go to the horse's mouth for up to date information.  

It is also past the time when the work of the research group and the Bannasch Laboratory should be acknowledged by various Connemara breed organisations and their executives.  This surely a matter of courtesy at the very least.

Feel free to comment on the HWSS facebook page

A Picture Story of the Hooves of an HWSS Affected Pony

This is the story of a pony in Germany.  This pony although born and reared in Germany has parents which were born and reared in Ireland and is in fact of solely Irish bloodlines.

"My pony came to me in Oct. 2009. Her hoofs naked and bad. I thought with some serious hoofcare it would go better day by day. So I tried hard for 1 year. Than I decided to give her iron shoes. The effect was, that she could go without pain for the first time. The horn growed longer and it looked really nice. See pics from Feb. 2011". 

Even though the pony was shod she still required support of bonding agents around the hoof wall but the hoof does  show a normal form.

The sole.

One shod hoof and the other hoof still to be treated.  The pony was kept pain free with diligent hoof  care.

"In May, at the end of her pregnancy, she was lame on her right front-hoof. Shoe away and we looked for an abscess. Not  one found. Bandage (see pic.). 

"This got lost and so the wall :(."

The unprotected hoof (not shod and bandage lost) disintegrated virtually overnight and this is the result.  Notice that the disintegration is between the layers of the hoof wall, not between the hoof wall and the underlying laminae as would be seen in White Line Disease.

The sole picture also shows that the breakdown is between the layers of the hoof wall and not in the white line.

Shoes and casting materials back in place. May 2011.

Then just 5 days ago (Feb 2012),  the weather changed from a period of heavy dry frost (-10--20C) to +2C and wet conditions.   A series of large chips broke and peeled from this hoof.  If you look closely you can clearly see the hoof tubules within the layers of the hoof wall.

The owner decided that something useful should come from yet another setback with the pony's feet and has photographed the hoof pieces from all angles and referenced them to a measuring tape.  The pieces have been labelled and stored in the correct manner in the owner's household freezer; just waiting for someone to take on further research on the biochemistry of these abnormal hooves.

This pony foaled in May a colt (now gelded)  His feet are absolutely normal.  This pony has sire siblings which also have HWSS.   Remember  the dam of this pony and other other affected ponies ALSO has to be a carrier; one cannot 'just' implicate the 'stallion lines' with this condition.

Thank you to this pony's owner for allowing the research group to use these photos and tell his and the pony's story.

The fun of Statistics or "Lies, damned lies, and statistics"

There is a saying (in English) that there are "Lies, damned lies, and statistics".  This saying has over the years been attributed to many people, the least of whom are Disraeli (a British politician of the 19thC) and Mark Twain. However because 'google' is our friend I went to check the veracity of the above mentioned quote and found that it pre-dates these two aforementioned gentleman. history of the lies quote .

The point being made in the quote is that statistics can be manipulated to support or demolish a particular argument, they can be incorrectly reported by the media for dramatic impact, wilfully misinterpreted for personal or political gain and  generally tend to turn people off  from wanting to know more about a subject.

However statistics are also a useful tool in epidemiology.  For those who do not know, epidemiology is the study of disease patterns within and between populations, over time.

The investigation into finding a cause for HWSS was accelerated by using statistics.  The probability of 26 apparently unrelated ponies, living completely different lifestyles, in different countries in different continents spontaneously all being afflicted with the same debilitating hoof condition is statistically unlikely; there had to be a common denominator.

Back in 2005 there were very few publicly accessible 'through the internet breeding data base resources' available.  Since then of course there has been a growth in such sites as all breed pedigree and sukuposti.  These sites well pre-date the official database of the CPBS.  Consequently if one wanted a comprehensive database of the 'state of the nation' of  even the local Connemara Pony genepool one had to construct a database from scratch by manually loading information from the various printed stud books and registers into a suitable computer programme.  

Papers of interest which arose from the building of  a privately assembled database can now be seen on line.

Connemara Pony Bloodlines in New Zealand
An Analysis of the Australian Connemara Pony Population

What has happened to all the stallion lines in Australia 

2007.05 Australian Connemara Stallion analysis 

All of these papers were written up many months prior to this particular database being used to determine whether there was a common link between the 26 apparently unrelated Connemara ponies which had clinical HWSS.  The information contained in these papers have no connection whatsoever with the HWSS research.  They are included because they demonstrate how statistics can be very helpful in making breeding decisions.  They are also of interest to those people who are (rightly) concerned about increasing genetic bottlenecks, decreasing genetic diversity and the negative effects of  'Founder's Syndrome' in the Connemara Pony both  in their own country and worldwide.   It would be great if other countries were to also emulate this work and do a similar analysis of their own pony populations.

Such work as has been done in New Zealand can also be achieved in other countries. One needs an extensive database which includes all of the breeding for example includes the total parentage of the OUTCROSS stallions, not just the Connemara pony side of the pedigree.

What these papers AND the pedigree work undertaken for HWSS research  does prove, is that studying standard four generation pedigrees is not a valid form of analysis in a small, closed genetic population such is the Connemara Pony WORLDWIDE.   Indeed even a seven generation family tree does not disclose all the possible permutations which, with one common ancestor, has  resulted in HWSS.

The private database being used by the research group, now has well in excess of 20,000 individual entries which originate with Number One in the Irish Stud Book, Cannonball.  Work has begun to code each entry for HWSS status (where known).  Ultimately the aim is to convert the database into a statistical analysis programme which will then be able to predict the level of penetrence of  HWSS carriers within discrete populations.   Doing this process is one of academic interest only, because a screening test will be available well before the data entry is complete.  It will be interesting to see whether the statistical projections are significantly different from the reality demonstrated by the screening, however.

Of course the screening test is not going to happen until the second phase of the research is complete.  The second phase does not commence until the fund raising has reached the target.   So another plea for money here.  The funds still required are well within the achievable; we are so close to achieving the goal, but not quite there - yet.

Genetic Diseases; why some people persist in breeding animals with them.

"Genetic Diseases in dogs and cats; What can we really do about them?"  (Robson, Mark. Vetscript, June 2009, page 6. Wellington, New Zealand)

What relevance does a paper on dogs and cats have to the issue of HWSS in ponies?  

Whatever the species, the principles of breeding sound, disease free animals is the same.  One of the comments Robson makes is that "one thing we have learned from dealing with breeders for many years is that logic does not often come into decision making".

Robson believes breeders are driven by the three 'Es': ego, emotion and economics. He goes onto express the opinion that for many breeders, the prestige of winning will overcome any long-term concerns genetic problems may cause in their dog's health.  Ego takes precedence over common sense.  Strong words?  Yes, but think about it.

Years spent breeding a line of animals with a particular appearance (type) which then turns up with a genetic defect is emotionally painful as well as a blow to the ego.  "Emotion may cloud a breeder's judgement and he or she may breed from favourites even when there is mounting evidence of ill-health in the line." (Robson).
The thought that years of hard work and breeding has resulted in the appearance of a genetic defect is very difficult for anyone to accept.  Denial is going to happen, it is a normal human response and is in fact the manner by which an individual's mental health is maintained until such time as they can cope appropriately with the challenge placed before them.  Also consider the scenario where all the animals on a property are afflicted. The defect is seen as 'normal' for the people who deal with the animals on an everyday basis and they actually cannot see that there is a problem, until it is pointed out by an uninvolved third party.

People who know that there is a problem within their breed (for example in specific dogs breeds  such as British Bulldogs or HYPP positive  horses) but who choose to continue to breed affected and afflicted animals are not 'in denial' from a mental health perspective.   Choosing to  continue to breed from these lines  is  considered to be more likely to be made on economic grounds.  Robson then goes onto say "where large numbers of animals are bred, concerns about individual animals and any genetic defects are lost in the herd mentality where the dollars are the primary endpoint" and is referring in this case to 'puppy mills'.  The equivalent to 'puppy mills' are found in horse breeding worldwide.

It is not all doom and gloom though.  Many breed societies do now have genetic screening tests for known genetic problems. To reduce the incidence in the population they require the results to be included on registration papers.   With some breeds and species a single copy of  a mutated gene is considered to be an asset, but active doubling up of the gene is strenuously avoided (for example the double muscling gene in breeds of beef cattle and sheep).   In most cases involving  horses  (as opposed to commercial food animals) the work to find out what the mutation actually is, has been both led and driven by the people most affected - the breeders who have had the misfortune to inadvertently breed affected ponies; this is certainly the case with the HWSS research.

Some countries now consider that breeding animals with a known genetic defect to be an Animal Welfare Issue, dictating that to do so is an offence under that country's legislation.  Now that the genetic link has been proven for HWSS, breeders within such jurisdictions will need to be assured of the HWSS status of any ponies which they may wish to sell or purchase in the future; to not do so could make  them  vulnerable to possible litigation. 

The next step in the HWSS journey is to find the specific mutation and develop a commercial screening test for it.  Once the screening test is perfected this will also be able to be used  for other horse/pony breeds.  The research group now has notifications from several individuals with concerns that HWSS also occurs in their own breeds.

Unless a problem is of high economic significance or of national or international importance, researchers only go 'looking' when 'someone' tells them that there is a problem which needs investigation; and of course also supplies the funding to pay for the research.

If everyone who reads this blog (and there are LOTS of you) were to donate $10, that would make a sizeable dent in the money needed to get the second stage of the research under way.   The last update from the Centre for Equine Health who are responsible for administering the donated funds for the HWSS research project was that the amount still required to start the second phase was $3500.00.

You can help the researchers at the Bannasch Laboratory help us, the breeders to 'get it right' with HWSS.  Put aside Ego, Emotion and Economics and make a small donation to UC Davis donation page

Wish to know more about HWSS? Book a presentation.

The research on HWSS has more depth to it than what is shown in this blog.  Only the basics have been put on the internet because the internet is not a secure medium.  Anyone can lift  files off the net and use these for what ever they choose; although unlikely people with an 'agenda' could be tempted to use such information to their own advantage and not for the greater good which is the aim of this research group.

Jocelyn Garneau-Davies was invited to a meeting of the American Connemara Pony Society to talk about HWSS which happened on Friday 13.  For this meeting the group put together a Power Point Presentation with a much greater degree of information.   The people present at the meeting found that the information which they saw greatly helped them in their understanding of the whole HWSS issue. 

The group has repesentatives in most countries.  If your Breed Society, farrier/podiatry or equine group is interested in hosting such a presentation then email us.   Translations still have to be made into other languages, so please do not try and book a presentation for 'next week' :)

The results from the Genome Wide Association Study

This morning the results from the GWAS arrived in the inbox of the Connemara Pony Research Group; much earlier than was expected.  The reason they came in early is because there is no questioning the results. There is no doubt that the DNA of affected ponies and their close relations (parents, full or half siblings) is very different from both  the 'control' Connemara ponies and the Horse Genome Map.

This area of difference is call a 'candidate region'.  The candidate region which has been determined by the GWAS is in the area where the genes for keratin metabolism have been mapped.

Keratin metabolism controls how hoof, hair and horn grows in all mammals.

We now know definitely that there is something different happening in the genes of  HWSS affected ponies.   The area where this difference occurs supports the working hypothesis for HWSS.

Where to now?

The next stage requires the candidate region of all the 'positive' ponies in the GWAS to be investigated at a more refined level.  We now know where to look and now need to look much more closely to find out what is actually happening in the genes in the candidate region.
To conduct this research, of course requires more funding.  The Centre for Equine Health already holds the balance of the donated funds, not used to pay for the initial GWAS.
With this money already in-hand, the next stage of the research requires another US$8000.    The research group and the Bannasch Laboratory are hopeful that people will support this next stage of the research by making donations to pay for the sequencing of  the candidate genes.

You can make your donations here http://www.vetmed.ucdavis.edu/ceh/give_online.cfm

Bannasch Laboratory also wishes to let pony owners worldwide know that they now want more samples from HWSS affected ponies and control ponies.  The first point of contact for pony owners who wish to become actively involved in this research by submitting blood samples to the laboratory is the Connemara Pony Research Group       connemara.pony.research.group@gmail.com

Best Wishes for 2012

2012 will hopefully bring to us the resolution that we wish when the GWAS is completed and analysed.  

In the meantime Best Wishes go out to all, for the New Year of 2012 from the team at the Connemara pony Research Group.

Waiting is difficult..

After working on this project for so many years, the final few weeks of waiting for the preliminary results to come through from the GWAS is proving difficult.
Bannasch Laboratory has told us expect these results 'sometime' during the first week in February.
What we are hoping to see in these results is that on the Connemara Pony genome there is a 'region of interest' which shows up ONLY in the known affected and known carrier ponies.

This region of interest will then require closer investigative work to be conducted to establish exactly what is 'going on'.

"Good things come to those that wait".

Preliminary Results on the Genome Wide Association Study, for HWSS in the Connemara Pony

The official word from the Bannasch Laboratory at UC Davis is that the first results from the study are expected to be available in the first week of February 2012.

We have come a long way in a very short space of time.
The acceptance that HWSS is a distinct hoof condition has increasing support from equine professionals worldwide.  Input from farriers especially has been superb; these people are the ones who have been dealing with the problem at the 'coal-face'.   These professionals are themselves relieved that  others in their profession worldwide have been challenged by such an intractable hoof problem.  Reports have now come in informing the research group that a very similar hoof condition is noted as occurring with another minority native breed.

However to be successful in obtaining a diagnostic screening test for HWSS requires that Stage Two of the project can flow seamlessly from the results of Stage One.   Stage Two still requires more funds to make this happen.   The link to the donation page is here. http://connemara-pony.blogspot.com/2011/11/how-to-make-donation-to-support-hwss.html

Further information is also coming to the research group from owners and breeders around the world about their own experiences with attempting to treat the hooves of HWSS afflicted ponies.   The aim is to get a list posted on the blog of what people have found helps in keeping their ponies as sound as possible.

A 'don't try this it made things worse/made no difference and cost mega-bucks' scenarios will be included.  Owners can then make up their own minds as to what may just help for ponies in their situation.

How to Make a Donation to Support HWSS Research

Readers of this blog will already know that the Bannasch Laboratory at UC Davis has already commenced the SNP arrays to find the genetic mutation which causes HWSS.     This is but the first stage in the process required to develop a diagnostic test for HWSS.

The array has for the most part, been financed from private donations.  There has been a small funding grant received but this was not as much money as what had already been received from donors.   To carry on with the second stage of the research a further $US5000 is needed.
The research group has had many requests asking what is the best method to donate funds.
The Centre for Equine Health (which the Bannasch Laboratory is part of) has the giving page.



One of the research group members tried the system out, and it works.
UC Davis donation page

On the above page you will see a link to a secure page.  Follow this link and you will see the following:

You need to specify where the money is to go:

CONNEMARA DNA RESEARCH

and the person who is to be notified that a donation has been made:
DR CARRIE FINNO


The information above needs goes in the boxes on the far left of this screen (sorry cannot put arrows in to show you where).
The long thin field is where the Connemara DNA Research Fund goes.
The smaller box below: Dr Carrie Finno.















If credit card transfers are not your preferred method to make a donation  then you can send a cheque to the Center for Equine Health, One Shields Ave, Davis, Ca 95616. 
Send a letter accompanying the cheque stating that the donation should be directed to Connemara DNA research.


THANK YOU.

The Heartbreak of HWSS - up close and personal.

See the page on the sidebar

Genetic Diseases in Quarter Horses and Related Breeds and what we can learn from their research if we choose to do so.

One of the members of the research group found this very informative and comprehensive paper.   It is well worth taking the time to read it.   The link to the original article is below.

It is not only the QH and  the derivatives which have a suite of genetic disorders which thinking breeders need to be aware of.
Arabs have SCID, Lavender Foal Syndrome and Cerebellar Abiotrophy all of which are fatal conditions.
Fell Ponies have Immunodeficiency Syndrome (Fell Pony Syndrome - FPS) and not to be confused with SCID - fatal.  Recent research shows that the Dales ponies have a 17% carrier level for FPS in their population.

Warmbloods have EPSSM (also called PSSM - see article below), Recurrent Airway Obstruction (ROA) and OCD.

Belgian Draughts have connective tissue disorder similar to but not the same as HERDA.

All of these conditions have diagnostic tests available so there is no excuse for any person to breed two carriers and produce affected progeny.

Genetic Diseases in Quarter Horses and Related Breeds

by Heather Smith Thomas

EC July/August 2009

During the past two decades, research has shed light on a number of important genetic diseases in horses, including several defects that appear in Quarter Horses and other breeds that have utilized Quarter Horse bloodlines. Some of these diseases have cropped up in recent years, originating from mutations in popular animals. Thus the new trait was perpetuated in numerous offspring. Mutations are common in humans and animals, but generally don’t cause problems because they are greatly diluted in a very large gene pool. If the genetic change occurs in an animal that has hundreds or thousands of descendants, however, this may affect a wide number of horses.

Some mutations that have caused concern include HYPP (hyperkalemic periodic paralysis), first identified in 1985 and eventually traced back to the Quarter Horse stallion Impressive. Another serious defect, originally termed hyperelastosis cutis and also called HERDA (hereditary equine regional dermal asthenia) was first documented in the late 1960s and finally traced back to Poco Bueno. More recently, a muscle disorder called GBED (glycogen branching enzyme deficiency) was recognized as a killer of foals, causing late-term abortions, stillbirths or weak foals that don’t survive very long.

Some disorders are due to fairly recent mutations like HYPP and GBED, while others—like the muscle diseases that cause “tying up” episodes–have been with us a long time, maybe since the Middle Ages. Muscle cramping associated with exercise, or with exercise after a period of inactivity, has been recognized for more than a century. Terms such as azoturia (referring to dark urine), Monday morning disease, exertional rhabdomyolysis, etc. have been used to describe this abnormality and, in recent years, researchers have found there are several forms of this syndrome, with different causes.

The number of visitors to the blog keep on RISING and are way above expectation

The reaction to the information released through this blog has been dramatic and way more than what the group expected.

Of course now the contrary points of view are being aired. This was to expected and is in fact a sign of a healthy community.  The major counter argument being offered to this blog and the research group in general is that "we" have now caused 'irreparable damage to the reputation of the Connemara Pony worldwide'.


On the plus side though there has been far more responses along the following lines, than to the negative response like above:

" 'image of the breed be damned' - there are now too many cases where owners who now have or had affected ponies have been put in contact with each other because this group has gone public on the issue.

Their stories are heartbreaking, and typically involve years of frustration, anger, recriminations, and expense;  without exception they've been made to feel that the state of their pony's feet is THEIR FAULT.

By going 'public' these people have been able to find that they aren't alone, that its not because of some personal negligence on their part, and that while there may not be a cure, that at least they now have a name to hang the problem on. 

By going 'public' there have been many more affected ponies identified.  This shows that it is not  uncommon, unlike what the breed societies would like everyone to believe. " 

ON A MORE POSITIVE NOTE

The group hopes shortly to assemble a document which will be a collection of  'what has helped and what made no difference' for HWSS affected hooves.  There is little point in each owner having to re-invent the wheel.   Combined knowledge gives strength.

One piece of information which could be very relevant immediately, is that any feed formulations - such as Farrier's Formula, appear to require much longer treatment times than what would be seen in a normal hoof.  Also the improvement it will make will be much less than that seen in a normal hoof.   

The biotin research conducted on the Lipizzaners of Piber Stud and the Spanish Riding School (Josseck et al 1995) showed that the average response time for any improvement was 33 months.  This is way in excess of the time it would take for complete renewal of the hoof wall.   These researchers also concluded that there was a genetic component involved in the foot problems seen in this strain of Lipizzans.   Another project conducted in the UK (Reilly,) looking at the use of Evening Primrose Oil  to improve hoof quality (this time using Irish Draught xbreds) showed a very extended length of time before any positive response was detectable.

Pony feet, the researchers have informed us grow at a slower rate than horses.  So one would expect an even slower response rate to feed supplements such as FF and EPO. 

None of the HWSS ponies which were put onto feed supplements for hoof health were treated at a clinical level for more than 24 months before the owners were advised to euthanase them so there is no information available as to whether feed supplements do help with modifying the effects of HWSS.

Another idea which has been put forward by a biochemist is that it may be worth looking at utilising  the polymers which are UV activated and are used in human medicine and dentistry, as a method of  improving the quality of the  permeability barrier on the hoof.  The fact that these are medical polymers would indicate that they are inert in biological systems.

Hopefully there will be people with such expertise in our readership who may be be able to give an opinion on this matter.  email us connemara.pony.research.group@gmail.com if you have any ideas or advice you wish to share.

Thank you

A picture of HWSS in a purebred Connemara pony in the UK

This blog has an in-built statistics facility which gives information about from which countries people log into this site.

It has been very intriguing that the lowest 'hit' statistics are from a country with one of the highest populations of Connemara ponies in the world.  
Any  idea that people may have that HWSS does not exist in this country should look at these pictures:

this foot is not the result of neglect, wet conditions/dry conditions/incorrect feeding, or poor farrier skills.

These pictures are now also up on the O A Curtis farriers face book page;

O A Curtis - farriers

Sandra Mesrine is it a connemara pony?
O A Curtis Farriers How did you guess?
Sandra Mesrine ‎:)

How HWSS has really affected so many people and their ponies

HWSS was unofficially brought to the attention of  some ICCPS delegates during a break in their technical meeting back in 1998.   Sadly for the breed as a whole and for specific ponies and owners, the information supplied then was not heeded.

Human nature being what it is, people will have wanted to protect their own interests, so the 'don't want to know' attitude is not surprising.

But what have been the true costs?  Consider the following.

HWSS has not been talked about openly - there has been plenty 'talking behind the hand' in some areas BUT for the most part until now, owners and breeders have been on their own dealing with this issue.

OWNER GUILT is one of the prime psycho-social effects of  having to deal with such a problem in isolation.   Up until now there has been no support group to turn to.  The level of denial to there even being a problem is also very high.   Owners feel guilty that something they have or have not done in the care and welfare of their pony (ies) is the cause of this debilitating hoof condition.   The farriers and veterinarians have had no knowledge of the condition and have been treating these ponies for all manner of pathologies - usually White Line Disease (WLD) or fungal and bacterial infections.   All at great cost to the owners and with no or little positive results (thankfully this is now changing with prominent veterinarians, farriers and hoof experts following the progress of this research).

Just think about the effects on such an individual who has bred 4 such ponies and has been struggling on in isolation to do the best for them?   To suddenly be made aware just a matter of weeks ago, that there was research happening this area and that the hypothesis is that it has a genetic basis, was an overwhelming relief for this person.
Actually there are 4 such pony owners - this is not some hypothetical situation - who have come forward in the past month from 3 different countries, and whose ponies have supplied blood samples to the Bannasch Laboratory for the GWAS.   These owners have met all the collection costs and FedEx expenses from their own pockets; the research group and Bannasch are so grateful to them for doing this.

Sadly there is no cure for HWSS; some cases can be 'managed' but some ponies are so severely affected that  the only 'cure' is euthanasia.  Sadly for one of the four people mentioned above this is the outcome for another lovely pony (yes there have been more ponies from the same person who have had to be euthanased on humane grounds, even with the best of care) .   Except that THIS time the owner, the veterinarian and the farrier all had an idea about what they were dealing with.

This pony will add much information to the research project as all four legs (hooves) and other tissues have been sent to UC Davis and are undergoing pathology testing.  The preliminary results confirms that these hooves do NOT  have the pathology seen with 'normal' hoof  structure.

There is a great amount of scuttlebutt presently zipping about the interwebs on HWSS.  The number one take away message is:
This is NOT a curable condition in but some cases it can be managed so well that the pony can live an active and productive life.  


Plus

• The ponies who are being reported, via the scuttlebutt, to have been 'cured' have in fact been euthanased.   
• It is a worldwide problem and definitely not restricted to any one country.   
• It IS more common in some countries and some areas within certain countries.
• Don't point the finger at other people - you too could well have a carrier pony standing in your paddock/barn.  You have either not yet bred it OR have lucked out and 'won' the 50% lottery.   (carriers have a 50% chance of passing the defect on to their offspring - simple Mendelian genetics predicts 1:4 ratios of affected to non affected offspring when two carriers are mated). 

Become part of the SOLUTION.

•  Help with donations to Bannasch.  
• Contact this group if you have an affected pony or have bred an affected pony.   Part of the research involves building family trees.   The database is already large with over 21,000 individual ponies listed from all over the world but more information is required.

Exciting Exciting NEWS. SNP Arrays to commence

Today I have received confirmation that there has been sufficient donations received by the Centre for Equine Health (UC Davis) (CEH) combined with a small grant, that the first stage of the Genome Wide Association Study (GWAS) is ready to start at the Bannasch Laboratory.
This is such exciting news that we have progressed so far, so quickly.
From the researchers at Bannasch Lab I received this today:

"We are still interested in donations for the 2nd stage of the project (either SNP genotyping additional samples or sequencing a candidate gene/region).
I am waiting on 9 more unaffected distantly related control samples to come in this week and then we plan to send out the DNA. We should have the results before the holidays and some preliminary information by the end of the year."

The next stage of the project requires $5000.

The research group has no idea who has donated money via CEH for this work to commence so promptly, but we thank you from the bottom of our collective hearts.

For those of you who wish to know more and to understand what is about to happen


The whole process involves looking for areas on a gene (or genes) which are different from what the reference genotype shows.   There are breed differences so that it why the genome of non-related ponies are needed to compare the genes of the affected ponies too.  In other words there can be specific genes which are not on the reference (library copy) of the horse genome, but which are in fact totally normal in another breed.

Because we already know what the problem is at a functional level, then the genes influencing lipid metabolism in hoof (keratin) structure is a an area for possible candidate gene(s) or a region within one of the keratin coding genes.