Current Research Areas
The CEVR supports researchers with a wide variety of interests. Current areas of strength for the Center are outlined below:
Laminitis Research
Laminitis is a painful condition of the foot that causes severe lameness and damages attachments that hold the hoof in place and support the weight of the horse. This condition is commonly known as founder and many horse owners have encountered this problem. It affects horses of all breeds and disciplines – from the show horse to the family pony. Once the process has started, laminitis can damage the attachments of the foot so severely that the horse is unable to be ridden and may have to be euthanized. Laminitis is a devastating disease that has been identified as the number one priority for equine research nationally.
University of Tennessee researchers have been studying laminitis in horses since 1994 when Dr. Dallas Goble and Dr. Steve Adair published their new technique for measuring blood flow within the equine foot. Dr. Adair continues this work and is measuring blood flow to assess new treatments for laminitis. New shoeing and trimming techniques for managing chronic laminitis are also being developed in collaboration with Mr. Dudley Hurst, who is a registered farrier with extensive experience in the area of laminitis.
In recent years, Dr. Nicholas Frank and his graduate students have been focusing on causes of laminitis in horses. They are working to determine why certain horses are predisposed to laminitis. This work has led to several exciting discoveries that may result in the development of new treatments for preventing laminitis in the future. Their first discovery was a link between obesity and disturbances in the movement of glucose throughout the body. This is important because we known that overweight horses and ponies are predisposed to laminitis. Obesity and laminitis are linked by a diabetes-like condition called insulin resistance. Just as people with diabetes suffer from blood flow problems in their legs, horses and ponies are more likely to develop laminitis if this condition is present. Management of obesity and insulin resistance can therefore lower the risk of laminitis. Their second discovery was a link between systemic illness and laminitis. Laminitis develops in horses that are suffering from colic or diarrhea. Dr. Ferenc Tóth was the first CEVR graduate student and first recipient of the Charles and Julie Wharton Laminitis Fellowship. He successfully completed his PhD in May 2009 and his work showed that the inflammation associated with intestinal disease induces insulin resistance. These factors combine to cause laminitis in horses, which reaffirms the importance of aggressive anti-inflammatory treatment for the prevention of laminitis.
Anesthesia Research
Dr. Tom Doherty and residents from his section conduct research to improve anesthesia protocols for horses. They have examined drugs to reduce pain sensation during surgery and different combinations of anesthetics.
Endocrine disease research
There are two important hormonal diseases of horses – equine Cushing’s disease and equine metabolic syndrome. Both disorders are studied at the University of Tennessee by Dr. Nicholas Frank and his research group, Dr. Carla Sommardahl, and Dr. Hugo Eiler. Research performed at this university has improved diagnostic testing for equine Cushing’s disease, which can be controlled with treatment once it has been diagnosed. A research study was recently conducted to determine whether diagnostic tests for Cushing’s disease are affected by season or diet in horses. Results clearly show that diagnostic test results are altered during the late summer and fall in Tennessee, so testing should be avoided during these seasons. The study also revealed that older horses with Cushing’s disease show more pronounced responses to sugars found in grass growing on pasture, which is likely to raise the risk of laminitis in these animals. Both of these findings will help horse owners and veterinarians to diagnose and manage this disease.
Equine metabolic syndrome was first recognized in horses in 2002 and Dr. Frank’s research group has been involved in the discovery and characterization of this condition. This syndrome is composed of obesity, regional adiposity in the form a cresty neck and other fat pads, insulin resistance, and laminitis. Horses and ponies that develop laminitis on pasture often suffer from this syndrome.
Researchers from the CEVR have made several discoveries in this area. The first discovery was that insulin resistance is a key factor in the development of laminitis and this condition occurs in some, but not all obese horses. Testing methods have been developed at the University of Tennessee to diagnose insulin resistance and therefore identify horses that are at higher risk for laminitis. The second discovery involves the treatment of obesity and insulin resistance in horses. Improvements in diet and exercise are always recommended, but a drug that accelerates weight loss has been identified and tested at the University of Tennessee. Research in this area is ongoing as one of our CEVR graduate students Kelly Chameroy pursues her PhD degree.
Hyperbaric oxygen therapy research
Researchers from the CEVR have assessed the use of hyperbaric oxygen therapy (HBOT) for the management of skin grafts and for the prevention of systemic illness caused by bacterial infection. Researchers in this area include Dr. Jim Schumacher, Dr. Steve Adair, Dr. Tom Doherty, Dr. Carla Sommardahl, and Dr. Madhu Dhar. Hyperbaric oxygen therapy has been established at the University of Tennessee through the work of Dr. Dennis Geiser. Click on the following link to find out more information about HBOT.
http://www.vet.utk.edu/departments/LACS/hbot.php
Nutrition Research
Our research focuses upon the management of obesity and insulin resistance in horses. A research study was recently performed to determine whether a dietary supplement containing chromium and magnesium controlled insulin resistance in horses. Results showed that the supplement was ineffective, but this finding was still useful to horse owners and veterinarians because many of these products are advertised in magazines and on web sites. It is important for researchers to determine whether claims made by commercial companies are supported by scientific results.
Lameness Research
Several members of the CEVR perform research to study problems occurring in horses that are receiving treatment in our teaching hospital. Dr. Jim Schumacher has recently performed a study to examine suspensory ligament desmitis, which is a cause of lameness in horses. This study has improved our understanding of the condition and helped us develop methods for treating the problem in horses. Laminitis is another important cause of lameness and, as stated above, clinical research and experimental studies are ongoing at the University of Tennessee.
Gastrointestinal Research
This has been area of strength for the University of Tennessee for many years because of work performed by Dr. Frank Andrews on gastric ulcer disease in horses. This work has included the assessment of different diets and treatments to prevent gastric ulcers. Dr. Andrews left the University of Tennessee in August 2008, but Dr. Carla Sommardahl and Dr. Madhu Dhar are continuing this work. Dr. Dhar recently completed a study to examine gene expression in the lining of the stomach and the effects of acidity on the membrane pumps found there.
Laminitis also occurs after systemic inflammation caused by intestinal disease and Dr. Nicholas Frank and his group conduct research in this area.
Reproduction Research
This is an area that we are developing at the University of Tennessee. Dr. Tulio Prado has worked with Dr. Jim Schumacher to develop surgical procedures to treat urinary contamination in mares. A new research project is planned to assess the impact of obesity on fertility in mares.