Australian Wild Horses at Risk for Laminitis After Floods Turn Scrubland to Pasture

by Fran Jurga | 6 March 2009 | Fran Jurga's Hoof Blog

The Australian Equine Brumby Research Unit, led by Dr. Chris Pollitt, is hard at work in western Queensland, where the natural habitat of many wild horses is underwater, thanks to once-every-ten-years floods. Yes, as fires destroyed Victoria in the south of Australia, floods were inundating the North!

While laminitis is not believed to be common in wild horses, it apparently is quite a risk during situations like this and might even be thought of as a form of very painful population control. As the floodwaters are absorbed into the desert-like soil or drain into nearby dried-up lake beds, the desert will bloom and even sprout grass.

The foot of a wild horse with laminitis

The wild horses are accustomed to living on scrub weeds, and the researchers assume that the flush of grass causes laminitis. But they have to prove that it is the grass, and that they horses do have grass laminitis. Laminitis might also be caused by a poisonous plant or some other side effect of the environmental change.

The wild horse research group is the brilliant step-child of the Australian Equine Laminitis Research Unit, which studies laminitis in domestic horses and seeks both a way to prevent the disease and to understand the mechanism by which it attacks the inner hooves of horses.

Assisting Dr. Pollitt are several student researchers and, temporarily at least, the able-bodied American, Dr. Don Walsh of the Animal Health Foundation who is on sabbatical to perform laminitis research with the Australians.

The core mission of the brumby (that's Australian for "wild horse") research is to understand how environment affects the wild horse and how its feet change as the environment changes. To that end, the group is tranferring horses between herds and observing and recording the adaptation stages...and whether the horses can even survive the drastic extremes of Australian climates and terrains.

Dr. Pollitt and his group have plenty of wild horses to study: Australia has more wild horses than any other place on earth.

The group has a lively web site with down-to-earth research reports and monthly newsletters, and is a most worthy cause for anyone wishing to support equine research that will benefit horses everywhere, as we finally learn how our management of horses may need to change to maintain the healthiest hooves and the soundest horses.

Hoof Blog Recommends This Link: http://www.wildhorseresearch.com

To read the February Newsletter from the researchers, click here.

To purchase freeze-dried specimen feet of Australian wild horses, click here.

To donate to the research efforts, click here.

© Fran Jurga and Hoofcare Publishing. No use without permission. You only need to ask. Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. This blog may be read online at the blog page, checked via RSS feed, or received via a digest-type email (requires signup in box at top right of blog page). To subscribe to Hoofcare and Lameness (the journal), please visit the main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found. Questions or problems with this blog? Send email to blog@hoofcare.com.

Australian Fire Survivor Horses Now in Danger of Heat-Induced Laminitis

This has to be the animal-lover's photo of the year; a firefighter in the Australian state of Victoria shares his bottle of spring water with a burned koala. (photo links to Horse Deals Australia blog)

The numbers are staggering. Wildlife and public health officials in Australia estimate that as many as one million animals may have been killed in the wildfires that ripped through the state of Victoria last weekend. As if that news isn't bad enough, there may be a double whammy coming for horses who had to stand on the scorched earth: the fire in the bush is over, but the fire in the feet may be only beginning.

We know that rapid and continual cooling by the icing of the horse's lower limb and digit ("cryotherapy") can clinically prevent laminitis, as proven in studies by the Australian Equine Laminitis Research Unit at the University of Queensland, directed by Dr. Chris Pollitt.

But can the inverse be true? Can heat cause laminitis?

Dr. Pollitt is flying south to Victoria to help with rescue efforts and provide veterinary services for the hundreds of horses displaced or injured by the wild bushfires that ripped through the countryside in Victoria.

The University of Melbourne’s Faculty of Veterinary Science in Victoria is providing free care to pets and horses injured in the recent fires. Professor Ken Hinchcliff, Dean of the Faculty there, says that veterinary clinic staff at the university are deeply concerned.

Dean Lewis of the Victoria Farriers Association has spoken up about the danger of horses "losing their hoof capsules" and has offered the services of his member farriers to help with rescue operations.

One of the things that touched me was that the rescue center are having trouble feeding the horses, and put out a call for soft lucerne (alfalfa) hay. So many horses have burned muzzles that it is painful for them to eat regular hay with its stiff stalks poking their burnt flesh.

The burns on this cat's paws are typical of what pets and livestock have experienced. This cat is receiving veterinary care at the Victoria Animal Aid fire assistance center.

Triple R Equine Welfare Inc. (TREW) warns horse owners and anyone wishing to help, "The immediate threat to horses left stranded in burnt properties is damage to hooves. Prolonged exposure to hot ground will cause a low grade overheating, that develops into heat induced laminitis. The prognosis for horses suffering this condition will be extremely poor. It is imperative the we move swiftly to relocate horses off burnt properties."

The textbook Technical Large Animal Emergency Rescue by Gimenez, Gimenez, and May (Wiley-Blackwell 2008) offers some insight into what body conditions of a burn victim horse may contribute to laminitis and hoof capsule detachment:

"Thermal injury produces local and systemic responses. In the local (skin, which would include the hoof) response, inflammation is the primary reaction, caused by damaged, leaking tissues and blood vessels. Tissue fluid and electrolyte shifts cause inflammation and fluid loss...

"Tissue injury continues for 24-48 hours after the initial thermal injury, therefore the burn will increase in severity over that period of time. Necrosis (death) of the dermis and epidermis in full-thickness burns creates a hard, leathery charred appearance to the skin; this is called eschar (Pascoe 1999). As the eschar sloughs, it creates an increase in open wounds."

It's pretty straightforward to think that burned hooves are a danger in themselves, even though farriers routinely hot-fit hooves and prolonged hot fitting has not been shown to be a danger to hooves. Burned coronets would affect the blood supply to the lamina within the hoof, which would probably already be decreased by the inflammation, edema, and compromised circulation.

Let's keep all the Australians--two-legged and four-legged in our thoughts, and hope that we can learn something about laminitis and how to prevent and treat it in future forest fire emergencies.

Sam the Water Guzzling Koala is recovering at a shelter; she too has extensive burns on her feet. It looks like she's been to the hairdresser, too.

© Fran Jurga and Hoofcare Publishing. No use without permission. You only need to ask. Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. This blog may be read online at the blog page, checked via RSS feed, or received via a digest-type email (requires signup in box at top right of blog page). To subscribe to Hoofcare and Lameness (the journal), please visit the main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found. Questions or problems with this blog? Send email to blog@hoofcare.com.

Favorite Video: Horse Owners Beware of Seasonal Weight Gain Over Winter Months

by Fran Jurga | 2 December 2008 | www.hoofcare.blogspot.com

Most horses and ponies are not as overtly obese as this pony. The videos posted for you today explain the subtleties of weight gain in horses and their not-so-subtle effects on a horse's health. Chris Pollitt photo. (thanks!)

The red line on the thermometer is dropping. The blankets are out. The feed bucket gets an extra half a scoop. Soon it will be an extra whole scoop. Or two. In the deluxe barns, the heat comes on. "Can you bring the horses in early tonight? It's awfully cold...and make sure Bilbo has both his blankets on, ok?"

As countless horse owners continue to struggle with low-grade chronic laminitis and its more serious counterparts, we still seem to have as many overweight horses standing guard in winter paddocks as we did last winter. In spite of all the diet grain mixes, horse owners still love to feed their horses, just as they love to dress them in blankets. It's a visible sign that the owner cares, and is providing the best possible conditions for the horse. (Isn't it?) When the weather gets cold, adding more grain to the feed tub seems like a sensible, caring thing to do. (Isn't it?)

And when laminitis strikes, horse owners run through a gamut of emotions, from grief to guilt to an outpouring of excessive care and nursing. When, in most cases, it could have been avoided.

In this post you will find a three-part video from World Horse Welfare (formerly the International League for the Protection of Horses), a British-based charity that puts laminitis very high on its list of educational priorities.

World Horse Welfare horse care team leader Samantha Lewis shares good practical information with a horse owner in this video. She talks about the risks of laminitis, winter grazing, blanketing, weight taping, and a lot of other key concepts for horse owners.

She had my attention from the very first sentence: 80 percent of horses in Great Britain are overweight. How can that be? When she examines horses of different sizes and conformations, I start to understand that weight is a very deceptive variable in horses. And I may have been guilty of misjudging some horses in the past, according to Samanta's system.

I hope the regular readers of this blog will refer horse owners to this post to learn about the relationship of weight to laminitis and other health problems. If you're a vet or farrier, please recommend these video clips to your clients.

NOTE: In the shaded portion at the end of this blog article, you will see a small icon that looks like an envelope. If you click on it, you can forward this article (or any article in the entire archive of the Hoof Blog) to anyone you'd like to have this information. I think that the email icon shows up in some browsers and not others; sorry for this inconsistency.

This video set might make a great Christmas present instead of a bag of horse cookies.

Thanks to WHW for making these clips available. There's lots more information about obesity in horses on their website. For information about laminitis, please visit Dr. Chris Pollitt's laminitis research web site.

Here's Part 1:

 

 Here's Part 2:

 

 Here's Part 3: 

 

© Fran Jurga and Hoofcare Publishing. No use without permission. All images and text protected to full extent of law. Permissions for use in other media or elsewhere on the web can be easily arranged. Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. This blog may be read online or received via a daily email through an automated delivery service. To subscribe to Hoofcare and Lameness, please visit our main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found. Questions or problems with this blog? Send email to blog@hoofcare.com. Comments to individual posts are welcome; please click on the comment icon at the bottom of the post.

The Environmental Hoof: Will Wild Horse Feet Adapt to a Sudden Change in Climate and Terrain? Australian Researchers Switch Brumbies, Observe Hooves

By Fran Jurga and Brian Hampson | November 25, 2008 | www.hoofcare.blogspot.com

Herding horses out of the bush in Australia; photo by Dr. Chris Pollitt

One of the challenges to the paradigm of the wild horse foot as a model for domestic horses has been the criticism that most studies have been done on horses running on arid terrain in the US west. Skeptics have pointed to the platter feet of sand dune horses on the east coast of the USA and variations in herds like the Sable Island ponies that have been limited in genetic input.

Dr. Chris Pollitt was scratching his beard over that one when he launched his Wild Horse Research Project at the University of Queensland in Australia last year. Would it be enough to study generic brumby hooves in the wilds of Queensland? Or would he need to hoof it further afield?

For the past six months, Pollitt and his lead researcher, hoof science PhD candidate Brian Hampson, have indeed been hoofing it, to the wilds of the far Australian outback.

“The aim of this project is to determine if the typical shape of the feral horses’ feet from soft sandy country will develop into the typical shape of feet of the rocky country feral horses when placed on hard rocky country for six months,” writes Hampson. “The reverse case will also be tested.”

“There is currently no evidence that horses’ feet can adapt to suit the terrain they are moving over. If the foot type of the feral horse can change by changing the substrate, then domestic horse’s feet, too, can be presumed to respond to a change in environment. We will demonstrate that sub-optimal foot conformation can be rehabilitated by movement over the right terrain.

“It has been confirmed during the first 12 months of this project that feral horses living on soft sandy country have long and often splayed hooves. Feral horses living on hard rocky country have short, rolled hooves. We will swap six horses from each of these environments for six months to test the effect of the environment on the foot type," he writes.

This foot collected during previous studies from the Waterloo Station bush camp is from a horse that lives on dry rocky ground. (Chris Pollitt research series photo)

This hind foot is typical of the brumby feet from the sandy environments of Australia. (Chris Pollitt research series photo)

He continues: “It is hypothesized that the foot type of the subject horses will switch from the sand model to rocky model and vice versa. We hypothesize that it is the environment that shapes the horse’s foot rather than predetermined genetic factors. It is currently believed that certain breed types are predisposed to certain foot types. By exposing the same horse to two different substrate conditions, the breed factor will be controlled.

“We will use this information to devise a better housing model for the domestic horse. The housing model may include hard substrate and movement stimulation. Our aim is to improve the foot health of the domestic horse.”

Pollitt and Hampson plan to pen an important publication from the study; the results will be presented at scientific conferences in Australia and the USA, and publicized to farriers and horse people during an Australian tour.

You know there had to be some drama and poetry in this study, as you will find if you look beneath the surface of most of Dr. Pollitt’s research. In this case, Pollitt and Hampson will saddle up and ride into the back country. No helicopters for them! They will not only capture their chosen brumbies, but gentle them and then lead them out of the bush.

The chosen environments are the sandy beaches of the Gulf of Carpentaria on the north coast of Queensland, and the rocky desert of Central Australia, 400km southwest of Alice Springs, if you have a map handy. Both locations have feral horse populations in excess of 10,000 horses and have been well studied by Pollitt’s team.

Horses will wear a GPS tracking collar for the six months of their release and a VHF beacon for relocation. Horses' feet will be photographed, radiographed, and their loading pressures and pattern will be assessed using an RS scan pressure plate, both before and after the swap. They will also measure hoof wall growth rate over the six month release period.

The Australian Wild Horse Research Project is unique in that the researchers include not only scientists and students but private citizens who are interested in wild horses or hoof physiology. Donors to the projects are eligible for consideration as mates on the trail, presuming you can brew a decent Billy Tea and waltz beside the billabong. Australia has more wild horses than any other place on earth; in excess of 500,000 horses roam freely, according to Hampson, but he notes that they are subject to periodic sustained drought and culls by "government bodies and private graziers".

Visit wildhorseresearch.com for more information about how you can support the research…or possibly be part of it. We will all certainly benefit from this Outback experiment.

PS I thought this post would be appropriate since today is the premiere of the film Australia in the USA.

© Fran Jurga and Hoofcare Publishing for the Wild Horse Research Project and Dr. Chris Pollitt. No use without permission. Permissions for use elsewhere can be arranged.

Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. This blog may be read online at the blog page, checked via RSS feed, or received via a digest-type email (requires signup in box at top right of blog page).

To subscribe to Hoofcare and Lameness (the journal), please visit the main site, www.hoofcare.com, where many educational products and media related to equine lameness and hoof science can be found.

Questions or problems with this blog? Send email to blog@hoofcare.com.

Looking Back at 2007: This About Sums It Up, or: Israeli Vet Reminds Us Why We Are Still Just Spinning Our Wheels in Hoof Research

{Syndicated content copyright 2008 Fran Jurga's Hoof Blog and www.hoofcare.com}

"Incorporation of more advanced analysis systems in recent years has provided veterinarians with abundant new information related to the various effects of common shoeing and farriery techniques on foot and lower limb biomechanics. It is quite obvious however, that some aspects are still controversial or unclear. Among these controversies are the effects of change in heel height on the angles of the PIP ("pastern") and MCP ("fetlock") joints and on the strains of the flexor tendons and SL ("suspensory ligament").

"Comparisons of unshod and shod horses are rare, but the use of analysis systems, such as the pressure mat, may help to clarify debate about the purported benefits of shoeing horses versus leaving them barefoot. Fine (finite element) analysis of the distal limb seems to be limited by the complex anatomy. Indeed, it seems that a full understanding of the function of smaller structures, such as the distal sesamoidean or collateral ligaments, may only be achieved with the use of computer simulation.

"Finally, it should be noted that from an evidence-based perspective, most studies that have been performed evaluating the biomechanical effects of the common shoeing and farriery techniques have been performed using sound horses, and many others have been in vitro studies. Thus, although the information obtained from such studies is interesting, its direct clinical relevance is speculative and the strength of evidence is not as strong as is desirable. "

--from the summary of the paper "An Evidence-Based Assessment of the Biomechanical Effects of the Common Shoeing and Farriery Techniques" by Ehud Eliashar, BSc, DVM, MRCVS, published in Veterinary Clinics of North America: Equine Practice, in August 2007.

Translation: when it comes to hoof research, "evidence-based" is a relative term. The same sentiment was voiced at the Fourth International Equine Conference on Laminitis and Diseases of the Foot by Rustin Moore DVM PhD DACVS in his lecture "Evidence-Based Treatment for Laminitis".

For years, many respected voices have called for a standardizd protocol for foot research. We are expected to accept as gospel studies performed on treadmills. Bar shoes or wedges tacked on to only one front foot. Horseshoes nailed onto untrimmed, unbalanced feet. Shoes tested on ponies instead of horses. Raceplates on high-heeled non-racehorses. Shoes applied for testing without following manufacturer recommendations. And, in almost all studies, the lack of control data of the horse without shoes, or at least with normal flat shoes. Contrary data even exists as to whether horseshoes dampen or increase concussion.

Dr. Eliashar's paper points out changes in study results on the same condition when the horse is on a treadmill and controversies over interpretation of statistics on toe grab relevance in racetrack breakdowns.

Looking ahead, it makes sense to draw parallels between the struggles between Darwinism and creationism when comparing the arguments for the benefits of shoes vs natural (shoeless) trimming. When scientists like Eliashar and Moore are cautious about labeling existing scientific data as "evidence-based", the boat has some serious leaks.

For years, researchers like Chris Pollitt have asked, "How do you expect us to explain laminitis when we don't know how the normal foot metabolizes and grows and functions?" Researchers like Robert Bowker have mused, "I discovered this really interesting facet, but I don't know what it might mean..."

Kudos to those willing to admit that the function of the foot of the domesticated horse is still a mystery and that science doesn't have all the answers. Science may not have even been asking the right questions.

Happy new year, anyway!

Photo courtesy of Royal Veterinary College.

Return to hoofcare.com.

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Where's My Brumby Now: Chris Pollitt Offers Donors a Chance to Ride Along for Hoof Research...by Satellite!

I am posting a research brief from Dr. Pollitt that should be of interest to every reader of Hoofcare & Lameness Journal. I think a brumby's hoof data would make a great Christmas present! Above: Australian feral horses ("brumbies") photographed from the air by Dr Pollitt in July of 2007 while conducting preliminary research.

Australian Hoof Research Project Brief: Determining the range of the Australian wild horse (Brumby) and the relationship to foot type and conformation.

Our team has spent much of the past 12 months investigating the use of GPS technology to track the movements of horses. As a result we have developed the ideal tool to track the day-to-day movements of horses in both the domestic and wild environments.

Our GPS tracking units allow us to accurately pinpoint the location, speed and altitude of the horse at one-second intervals for up to one week or at 30-second intervals for up to six months.

Domestic horse wearing a collar with GPS tracker attached.

A GPS unit attached to a strap around the horse's neck is able to fix the position of the horse by aligning its position with at least six satellites orbiting overhead and storing the data on board. When data is retrieved, it is interfaced with Google Earth to 1) produce an aerial photograph of the horse's movements (see photo) and 2) be overlaid on a geographical mapping system which applies the data to soil and vegetation type, use of water points and topography type.

This exciting technology is being applied to horses for the first time by our research team, with the goal of establishing a complete picture of the movements of horses, both domestic and wild, and how they interact with their environment.

The effect of movement and environment on the horse’s foot is a significant focus of the research. We know from preliminary work that the typical domestic horse’s foot travels very little (approximately 7 km daily) in comparison to its wild counterpart which may travel up to 50 km or more in a single walk. We have several populations of "Brumbies" (Australian feral horses) under investigation to determine natural foot structure and function under various environmental conditions.

Tracking data (3 days) from horses grazing a large 40-acre forested paddock

We are about to embark on the most exciting part of the research: to track the wild horses. Brumbies will be darted silently from a hide with a tranquilizer, giving the team two minutes to photograph feet, place permanent markers to determine hoof wall growth rates and attach the GPS collar (see photo).

On reversal of the tranquilizer, the horse will rejoin its family band unaware of the intervention. The same horse will be recaptured using the dart gun at the end of the trial to retrieve equipment and then released back to the wild.

This work will begin in March 2008 and continue for 12 months in locations in Central and Northern Queensland and the Northern Territory and Eastern Kimberly region of Western Australia. The project will ultimately identify the relationship between a horse’s movement and the effect on foot conformation, structure and function.

Our goal is to make well-informed recommendations of the ideal conditions to keep domestic horses to improve the well-being of their feet.

You can help in this groundbreaking research. The more GPS units we can attach to wild horses, the better and more accurate the data set will be. For AUS$3000 (approx $2,600 US) you can own and name a wild horse for the 4 to 6 month tracking season. We will supply photos and location data at the time of GPS attachment and, when retrieved, we will use the GPS download from your horse to generate a report using Google Earth maps.

Ultimately, the combined data from all the horses will be compiled into freely available scientific reports.

Please help if you can.

Professor Chris Pollitt
Professor of Equine Medicine
School of Veterinary Science
The University of Queensland
St Lucia, Brisbane, Queensland AUSTRALIA
email c.pollitt@uq.edu.au
website: www.laminitisresearch.org
fax 07 3365 2351

Note: To learn more about Dr. Pollitt and his observations of brumby feet, refer to "The Natural Hoof Down Under" in Hoofcare and Lameness Issue #69. He has also been a keen observer of zebra feet in the wild.

Double-click on any photo to view it in an enlarged size but please remember that these photos are the property of Dr. Pollitt and are protected by the copyright of Hoofcare and Lameness Journal and www.hoofcare.com, to say nothing of Dr. Pollitt's six satellites circling the earth.