Tuesday, August 30, 2011
Laminitis Research at the Australian Equine Laminitis Research Unit - Part 2
From the desk of Dr. Don Walsh,
During the past five years a significant portion of research efforts at the Australian Equine Laminitis Research Unit (AERLU) have focused on development of an effective drug delivery system, targeting the laminae of the horse’s foot. Pioneering work done under the supervision of Dr. Chris Pollit by Dr. Ali Nourian’s PhD thesis developed a method of intraosseous infusion (IO) of the distal phalanx (coffin bone) [IOIDP] of the horse’s foot in order to deliver drugs. My personal participation during the past two years at the laboratory has been to further test and develop the use of this drug delivery system.
I must admit when I first learned of the idea of drilling a hole through the hoof wall into the bone to access the unique circulation of the distal phalanyx, I was skeptical. I am from Missouri, the “Show Me State”. I thought it would be too painful for the horse to endure, and I needed to be shown this would work. Well, I was wrong and Drs. Nourian and Pollitt were right. Horses tolerate the presence of the needle in their foot with no discomfort.
The work I have been involved with the past two years has investigated the extent of the potential delivery of drugs within the lamellar circulation. The delivery system will allow clinicians to deliver a drug into the intraosseous space inside the bone. This space has direct communication to the sublamellar vessels and the laminae tissue. A slow infusion through the needle allows drugs to be delivered to the laminae to prevent or treat laminitis.
Further perfecting the Intraosseous methods and studying the complicated circulation of the intraosseous space is being done by Simon Collins, PhD who is completing a two year post doctrinal study of IOIDP. The general public probably has no idea of how much research it takes to develop something like this method. We have to be absolutely sure we are confident in the delivery system before it will be a useful tool to help horses with laminitis.
The Intraosseous Infusion Procedure is also of great benefit as a research tool when studying the effect of a drug therapy on the laminae. Currently Dr. Claire Underwood, as part of her PhD project, is developing a monitoring system inside the hoof to measure different concentrations of drugs that may be administered by the intraosseous method as well as other more conventional drug delivery methods. Assisting her with this project is Dr. Carlos Medina Torres working on his PhD. Both are under the supervision of Dr. Pollitt and Dr. vanEps.
For more detailed information on the Intraosseous Infusion (IO) method, see this entry on wikipedia.
I want to convey to the reader the sheer number of researchers and the varied projects they are working on. It is a many-faceted challenge and Dr. Pollitt and this team of scientists at AERLU are continually adding to the knowledge we have about laminitis and treating the disease. They are working with very limited resources and any donations to fund the laminitis research are greatly needed and appreciated. Please consider supporting this work. As always, one hundred percent (100%) of all public donations to AHF go directly to fund laminitis research.
Tuesday, August 9, 2011
As an introduction, my name is Dr. Don Walsh and I am the founder and president of the Animal Health Foundation, which was started in 1984. I have retired from active practice as an equine veterinarian after 42 years as of July 1, 2011. This new freedom has allowed me to pursue my interest in laminitis and the work of the AHF on a full time basis.
To that end I am now going to be much more engaged in writing for this website. Hopefully this endeavor will enable me to help educate veterinarians, farriers, and horse owners about the latest information regarding the disease. We have made a lot of progress in understanding laminitis and now we need to apply this information to help prevent laminitis from occurring in horses.
We are in the final process of producing a series of short videos which will be posted on the website. These videos will be a good source of information for people to understand the disease but more important prevent the disease from occurring in their horse.
From the desk of Dr. Don Walsh,
For the past two years I have been spending half of my time engaged in several research projects at the Australian Equine Laminitis Research Unit at Queensland University in Brisbane, Australia as a Industry Fellow in the Veterinary Science department working with Professor Chris Pollitt. I am presently here at the unit finishing up some work, and have written about a conversation that I recently had with Dr. Pollitt about the current projects.
Laminitis Research at the Australian Equine Laminitis Research Unit - Part One
August 6,2011 - A meeting with Professor Chris Pollitt, the head of the AERLU unit at Pinjarra Hills, University of Queensland, Brisbane, Australia
Chris Pollitt and I have been friends since 1995, and AHF has been funding his research efforts since that time. When we met yesterday we reviewed what we have accomplished. We now understand a great deal more about how laminitis occurs and have definitely defined two pathways: 1) the enzyme activated inflammatory pathway associated with major changes in the bacterial flora of the hindgut of the horse, and 2) the endocrine pathway associated with elevations in insulin levels in the bloodstream of the horse often associated with grass consumption.
Much of the success of the Lab over the years has been due to the efforts of the PhD students under Dr. Pollitt’s supervision. Dr. Andrew van Eps’ work, demonstrating that icing horses’ feet would prevent laminitis, has provided us with the only known method to prevent laminitis and is routinely used today in treating and preventing laminitis around the world. Dr. Katie Asplin’s work revealed the role of insulin in causing laminitis. The PhD theses of Dr. Cathy French and Dr. Bruce Mungall explained the activation of protease enzymes in the feet that leads to the loss of the support of the distal phalanx, of the laminitis associated with many disease processes.
Yet in spite of the successful research of all these students we still do not completely understand the processes of laminitis. The two most recent PhD students, Dr. Michell Visser and Dr. Melody deLaat, have each added new information about both of the pathways. Dr Visser’s work has enabled us to understand the changes occurring in the first few hours when laminitis is developing in the enzyme activated form of laminitis. Dr deLaat has brought our understanding of the insulin form of laminitis to new heights.
Despite all this progress there are still important questions to be answered. However Dr. Pollitt feels we are very close, and likened the situation to peaking the summit of a mountain and viewing the destination on the far horizon for the first time. Sadly allowing Visser and deLaat to continue their research as post doctoral employees of the laboratory is likely not going to happen because of a lack of funding.
Dr. Pollitt feels that if we were able to finance their salaries and research expenses as post doctoral scholars we would likely be able to conquer both forms of the disease. The cost to accomplish this would be approximately $600,000 over the next three years. While this is a sizable sum, it is very little in comparison to most medical research projects costing millions. Our ability to fund equine research falls back on the shoulders of horse owners and equine organizations, as government agencies have very little interest in horse research projects.
I am asking all of you to consider making regular donations to the AHF to help fund these important projects. If everyone who has a horse would make a small donation it would make a huge difference. Please consider my plea for your help.