Wednesday, March 30, 2011

Laminitis Research: Equine Insulin Resistance Does Not Respond to Metformin Medication; Diet and Exercise Remain Key to Laminitis Prevention

Morning all
Researchers in Australia tested the effects of a human medication, metformin, on ponies with insulin resistance, a condition that puts horses at risk for developing the endocrine or metabolic form of laminitis. The medication had no effect. (J.A. Holland image)
New research on the pharmacological management of the condition of insulin-resistance in horses and ponies has suggested that diet and exercise are still key in any management plan.

Insulin resistance (IR) is defined as the diminished ability of a given concentration of insulin to exert its normal effect on glucose dynamics in particular. This causes the body to keep releasing more and more insulin in order to elicit an effect. This may be one of the most predictable factors that determines whether a horse or pony could be more susceptible to what is commonly known as the "endocrine" or "metabolic" form of laminitis.
The University of Minnesota College of Veterinary Medicine's Equine Genetics and Genomics Laboratory explains insulin resistance this way:
Insulin  is a hormone involved in the regulation of glucose (sugar) levels in  the blood and tissues of the body.  In response to feeding, insulin is  secreted by the pancreas into the blood stream. Insulin in the blood  stream directs the glucose (sugar) absorbed from the food into the  body’s tissues including liver, fat and muscle.  Insulin resistance  occurs when insulin no longer has a normal effect on the tissues. In the  insulin resistant horse, the pancreas releases insulin into the blood  stream, and the insulin arrives at the tissues and binds the cells,  however the glucose enters the tissue cells at a much lower rate than  normal. This lower rate of glucose uptake into tissues results in higher  levels of blood glucose.

Horses and ponies compensate for  insulin resistance by secreting even more insulin into the bloodstream  in order to keep the blood glucose concentration within the normal  range.  Therefore, horses and ponies with EMS (Equine Metabolic Syndrome) have a higher  concentration of insulin within the blood, which can be measured to  determine if insulin resistance is present.
An important goal for owners and vets should be to prevent IR from developing, or to manage it before it contributes to the development/progression of other potentially life-threatening conditions. While the correct management of energy intake and exercise levels is thought to be essential, in some cases medication is also considered, especially when increased exercise is not possible. With no licensed drugs currently available for the treatment of IR in horses and ponies, off-label medications used for IR in humans are sometimes prescribed.

A trial was conducted by the School of Animal and Veterinary Sciences at Charles Sturt University in New South Wales, Australia and the Department of Clinical Studies at the University of Pennsylvania's New Bolton Center, in collaboration with the Waltham Equine Studies Group in Great Britain.

The study's intention was to confirm the positive effect of the human medication metformin on insulin and glucose dynamics in insulin-resistant ponies so that this treatment could be used as a positive control in other studies.

Glenys Noble BAppSc(Equine Studies) PhD, along with PhD candidate Kellie Tinworth BSc(hons) MSc, carried out the clinical trial in Australia. Six insulin resistant, non-obese ponies were repeatedly monitored by means of a frequently-sampled intravenous glucose tolerance test (FSIGT). Metformin ia a drug reported to enhance insulin sensitivity of peripheral tissues in humans without stimulating insulin secretion. It was administered twice-daily (15mg/kg BW BID) to three of the ponies for 21 days.

Meanwhile, the three remaining ponies formed a control group, and each received a placebo. After a wash-out period, the treatments were crossed over.  A Frequently Sampled Intravenous Glucose Tolerance Test (FSIGT) was conducted to evaluate the level of insulin resistance before and after each treatment.  The ponies' body weight, body condition score and cresty neck score were also assessed. They did not change during this study.

Ray Boston MSc PhD
is Professor of Applied Biomathematics in Clinical Studies at the University of Pennsylvania's New Bolton Center. He analyzed the data using MinMod, a computer program to calculate glucose effectiveness and insulin sensitivity from the frequently sampled intravenous glucose tolerance test, and Stata 10.1 statistics analysis software. No change in insulin sensitivity or glucose dynamics was seen under the control conditions or in response to the dose of metformin given in this study to these ponies.  

What does this study mean to horse owners? Clare Barfoot RNutr is the research and development manager at the British feed company Spillers®; she reviewed the research and said: “Although clinical trials with metformin are ongoing, this trial was consistent with our previous work showing that the bioavailability of metformin in horses is poor, and chronic dosing at these levels may not achieve therapeutic blood concentrations.”

She continued: “On this basis it would seem that a fiber-based diet that is low in starch (found in cereals) as well as  (being low in) sugar and fructans (found in grass), in conjunction with regular exercise if possible, is still the safest and most effective way to manage insulin-resistant ponies. It is important to recognize that, even if other doses of metformin are shown to be beneficial in the future for certain sub-groups of animals, full consideration to diet and management should remain a key tactic.”

The Waltham® Equine Studies Group, headed up by Dr Pat Harris MA PhD, VetMB DipECVCN MRCVS, provides the scientific support for the Spillers® and Winergy® brands sold in Great Britain.

To learn more: K. D. Tinworth, R. C. Boston, P. A. Harris, M. N. Sillence, S. L. Raidal, G. K. Noble (In press). The effect of oral metformin on insulin sensitivity in insulin-resistant ponies The Veterinary Journal; Available online 23 February 2011, doi:10.1016/j.tvjl.2011.01.015.

Thanks to Spillers for sharing this information with Hoofcare and Lameness.

© Fran Jurga and Hoofcare Publishing;  Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission.  You only need to ask. 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. 

Follow the Hoof Blog on Twitter: @HoofcareJournal

Join the Hoofcare + Lameness Facebook Page

   

Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.

Thursday, March 24, 2011

Midnite: Mini's Back on All Four Hooves Thanks to Prosthetic Boot

Midnite is a miniature horse at a rescue farm in North Texas; he has lived his whole life with a deformed hind foot that is missing its coffin bone, according to the Rescue.

Have you heard about Midnite? His story is all over the Internet and television news shows today. This young miniature horse was a law-enforcement rescue case who hopped into Ranch Hand Rescue in South Argyle, Texas on three legs. He couldn't put his left hind hoof down because...well, because it just wasn't there.

Midnite may have come to a safe, new home, but even as he gained weight and his overall health improved, he wasn't cheering up and that was a challenge. Almost as much of a challenge as simple movements like laying down, or getting back up. Scampering around with the other animals in the paddock wasn't an option. He won over the hearts of everyone at the rescue farm, especially director Bob Williams, and Bob decided to see if they couldn't do something to help the little guy.

The first attempt was using a donated Soft-Ride hoof boot (thanks, Soft-Ride!), with its removable gel-pad orthotics. These rehabilitation boots are familiar to many Hoofcare and Lameness readers, and lucky come in a vast array of sizes--even tiny enough for a mini. They taped the boot on the stump of his pastern each day and removed it each night. The staff massaged him, and powdered his stub, and they learned a lot about three-legged horses, especially how they need to re-disribute their weight after a long time of not using one of their limbs.



Here's a YouTube interview with Lane Farr, designer of the prosthetic clamshell boot.

From seeing a bit of improvement with the Soft-Ride boot, the rescue team, led by Bob Williams, scratched their heads and wondered what a human orthotics designer might be able to design for a tiny artificial hoof replacement.

Enter Lane Farr, a prosthetic designer with a lifelong connection to horses and a way with carbon graphite and fiberglas and gel foam. Lane designed a prosthetic support device that he told me both allows the little horse to bear some weight on what passes for a hoof, and also transfers some of the weight to a passive load share state rather than the direct load straight down the bony column through the pastern.

Lane told me that there is no medical history on the little horse,but that the assumption is that the deformity is congenital--it was present at birth.

The support/weight transfer boot has been through a couple of stages of re-design and Midnite is now able to run with it on, as you can see in the AP video.

I thought you might like to see these other videos, which show the boot up close. I'd love to see the inside of the boot and the gel construction and will ask Lane and Bob if we might get pictures of that. They're both busy with reporters today, and I know how they can be.

Hoofcare and Lameness apologizes for the ads on these and all videos. They are embedded by the hosts and they're just there, sorry. These television stations and media outlets are generous to allow Hoofcare and Lameness to embed the videos, or to post them on YouTube the way that Associated Press did. Many won't allow embedding at all, which is why many great stories can't be posted on the Hoof Blog. But for those who do work with us--the ads are ok, even though I will probably never need an orthodontist in Fort Worth! It seems like the least I can do for the privilege of sharing videos with you.

This short video has some good close-up views of the boot.

Finally, a big thanks, hats off and high-five to Bob Williams, the Board of Directors of Ranch Hands Rescue, Prostheticare, and Lane Farr for all their hard work on behalf of this little horse. I know some people say, "So what? Why bother?" but I would remind you that these are real people, without a lot of money to invest in a single case and who are pretty much self-taught, who took a risk and came up with a successful, low-impact way to help this horse.

What none of these videos tell you is that Ranch Hand Rescue could use your donation to help Midnite and all their other rescued animals. Here's a direct clickable link to their PayPal donation page. Please help them out!

It is true that with a $14,000 price tag, this clamshell design isn't going to sold every night on eBay, but this story has received more press than any story since Molly the Pony back in 2008, and I can tell you that that story had an amazing impact on the way that people think about going the extra mile and burning some extra brain cells before they give up on a horse.

I'd also like to thank Bob and Lane for taking the time to return my pestering calls when they have way too much going on already. Like me, they think you all, the readers of this blog, might be the ones who can make a difference.

Please prove them to be right.


 © Fran Jurga and Hoofcare Publishing; Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission. You only need to ask. 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.


Follow the Hoof Blog on Twitter: @HoofcareJournal
Join the Hoofcare + Lameness Facebook Page



Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.

Friday, March 18, 2011

Cheltenham's the Place to Be Today


Last year at Cheltenham, the celebrity riders, trainers and familiar faces got together and recorded a song about the race meet that they all love so much for a charity fundraiser.



In Gloucestershire, England they run a four-day National Hunt race meeting that is like no other in the world. It's like Saratoga on steroids: the best horses, the (hopefully) best weather, and a few hundred thousand of your very best friends all make sure that you have an unforgettable time.

Today, Friday, is the last day and it all culminates in the Gold Cup. Old rivals--and stablemates--Demman and Kauto Star may be eleven now, but they're heading out again. Kauto Star has won it twice. Denman won it once and was second twice. Oh, and there are some other horses in the race, too, like Imperial Commander, who beat both of them last year. (Denman was second, Kauto Star fell.) That these three Gold Cup winners could be back to challenge each other again is the flip side of the chronic unsoundness we take for granted in racehorses. These jumping horses, at their age, must have tendons of steel. The Gold Cup is three miles, two furlongs...with hills.

The sad thing is, this will probably be their last meeting. Safe run, you old boys!

© Fran Jurga and Hoofcare Publishing; Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission. You only need to ask. 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.
 
Follow the Hoof Blog on Twitter: @HoofcareJournal
Join the Hoofcare + Lameness Facebook Page
 
Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.

Thursday, March 17, 2011

St Patricks Day: It's Never Easy Being Green


green horse hooves
Is there anything people won't paint green on St. Patrick's Day? Between blinders and check reins, maybe these horses probably can't see what's happened to their feet. Photo by chautauquatourist


© Fran Jurga and Hoofcare Publishing; you are reading the online news for Hoofcare and Lameness Publishing. Please, no re-use of text or images without permission--please share links or use social media sharing instead. Do not copy and paste text or images--thank you! (Please ask if you would like to receive permission.)

In addition to reading directly online, you may also receive email "alerts" containing headlines and links(requires signup in box at top right of blog page).

The helpful "translator" tool in the right sidebar will convert this article (approximately) to the language of your choice.

To share this article on Facebook and other social media, click on the small symbols below the labels. Be sure to "like" the Hoofcare and Lameness Facebook page and click on "get notifications" under the page's "like" button to keep up with the hoof news on Facebook. Or, paste this article's address from the browser bar into your post.

Questions or problems with this site? Click here to send an email hoofblog@gmail.com.
  

Disclosure of Material Connection: No direct compensation was paid for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.

 

Farrier Image in Charity Print Auction for Japan

The auction has now ended. Thanks for your support of the people of Japan during this terrible tragedy.


For more information on the auction:
CPA - CHARITY PRINT AUCTIONS - JAPAN

Wednesday, March 16, 2011

Grayson Laminitis Research Funding Breaks New Ground: Richardson, Pollitt and Van Eps Join Forces for International Support-Limb Laminitis Prevention Study

Today the Grayson Jockey Club Research Foundation announced its selection for the 2011 round of equine research projects that will be funded.

Laminitis research figured prominently in the mix of subjects to be studied. In particular, two studies will receive support from the Lexington, Kentucky-based charitable organization.

The first covers the dreadful form of laminitis that led to the death of 2006 Kentucky Derby winner Barbaro. This will be a multiple-year study; "first year" refers to the funding applied for 2011. Andrew van Eps received his PhD at the University of Queensland in Australia by studying laminitis; his previous contributions have included the first studies of the use of cryotherapy to prevent laminitis.

Here are the Grayson descriptions of the new studies:

Laminar Energy Failure in Supporting-Limb Laminitis
Dr. Andrew Van Eps, University of Queensland--First Year
Andrew Van Eps BVSc, PhD, MACVSc, DACVIM
A frequent and disheartening result of injury repair is that the leg opposite the one injured develops laminitis. This is known as supporting-limb laminitis and is what eventually caused Barbaro to be euthanized. Although it is a common occurrence, the mechanisms of the malady have not been established.

This project is headed by a young researcher, but the co-investigators are world renowned Drs. Dean Richardson and Chris Pollitt.

Professor Chris Pollitt BVSc, PhD
The project involves testing the hypothesis that supporting-limb laminitis is a result of reduced blood supply to the connection between hoof and bone (lamellar tissue). Further, that the blood supply in normal circumstances is encouraged by a regular loading and unloading of the legs and hooves (alternating which one is bearing the most weight). Injury to one leg interrupts that alternating pattern.

The researchers will test the hypothesis with a state of the art, minimally invasive technique known as tissue mycrodialysis in conjunction with three dimensional computed tomography to develop effective methods of preventing or minimizing lamellar tissue energy failure.

Comments in the Research Advisory Committee evaluations included “may well provide immediately applicable strategies to prevent supporting-limb laminitis” and “really nice grant, new idea about a devastating problem.”

Dr. Richardson received second-year funding for his ongoing study of laminitis:

Dr. Dean Richardson, University of Pennsylvania--Second Year
In Vivo Gene Transfer for the Treatment of Laminitis

Dean Richardson DVM, DACVS
This project seeks to develop a gene therapy approach to prevent laminitis in the contralateral hoof when a horse is being treated for a musculoskeletal injury. This, of course, was what eventually ended the efforts to save Barbaro and is a frequent threat to horses with hoof and leg injuries. The well known research team already has compelling preliminary data which encourages the hypothesis that use of recombinant adeno-associated viruses can be used as vectors to deliver a therapeutic gene (TMP-3) to the lamellar tissues. This is meant to inhibit the damage to the epidermal laminae without disrupting the normal hoof structure.

Another completely new study will begin at The Ohio State University, where the mechanism of cryotherapy in averting laminitis will be studied and, hopefully, recreated via pharmacology.

Digital Hypothermia in Laminitis: Timing and Signaling
Dr. James Belknap, The Ohio State University--First Year
The most recent figures from a study involving the USDA and State Veterinary Medical Officers project that at any given time laminitis affects 8 of every 1,000 horses in the United States. Based on the American Horse Council survey that there are 9.5 million horses in the nation, that would indicate 76,000 horses being affected at any given time. Of those affected, the USDA survey found that 4.7% died or were euthanized, or about 3,572 deaths from laminitis annually.

The authors of this project report that “an integrated research effort over the last decade has enhanced the current understanding of the pathophysiology of equine sepsis-related laminitis (one of numerous causes of the disease). This has mirrored progression of sepsis research in human medicine by moving from (an earlier) concept . . .to determining that a marked inflammatory injury takes place and is likely to play a prominent role in tissue injury and subsequent failure.”

However, there have been persistent failure of systemic therapies for organ/laminar injury in both human and equine medicine. One advantage laminitis presents is that it effects the hoof rather than visceral organs, lending itself to artificial cooling more readily. In a present project funded by the Foundation, digital hypothermia (cooling of the hoof) prior to onset of carbohydrate overload-induced equine sepsis resulted in dramatic decrease in laminar inflammatory signaling.

The next goal is to find pharmaceutical therapies which can accomplish the same without the cumbersome aspects of maintaining constant hypothermia to the equine hoof (hooves).

Click here to easy-order the poster created with the Michigan State U. Equine Foot Laboratory

 © Fran Jurga and Hoofcare Publishing; Fran Jurga's Hoof Blog is a between-issues news service for subscribers to Hoofcare and Lameness Journal. Please, no use without permission. You only need to ask. 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.
 
Follow the Hoof Blog on Twitter: @HoofcareJournal
Join the Hoofcare + Lameness Facebook Page
 
Disclosure of Material Connection: I have not received any direct compensation for writing this post. I have no material connection to the brands, products, or services that I have mentioned, other than Hoofcare Publishing. I am disclosing this in accordance with the Federal Trade Commission’s 16 CFR, Part 255: Guides Concerning the Use of Endorsements and Testimonials in Advertising.