TEHRF research grants: 2018-19

One WCVM study focuses on a potential treatment for endometritis in mares that are susceptible to this infection. Photo by Caitlin Taylor.

The Townsend Equine Health Research Fund (TEHRF) has allocated more than $107,500 to support six equine health research projects at the Western College of Veterinary Medicine (WCVM). WCVM scientists and their collaborators will conduct the research studies over the next 24 months. Read the following summaries for more details about each study.

How can computer models improve treatment for roarers? 

David G. Wilson, James Carmalt and Michelle Tucker, WCVM

Recurrent laryngeal neuropathy (RLN), also known as “roaring,” causes a portion of a horse’s larynx to collapse during exercise — decreasing its airflow and its athletic performance. The disease affects about one in four thoroughbred yearlings and represents a significant financial loss to the horse racing industry.

Surgeons treat RLN by performing a prosthetic laryngoplasty, during which the collapsed portion of the horse’s larynx is pulled out of the airway with a suture. But this procedure has a high complication rate and is technically challenging to perform.

Recent developments in biomechanical engineering uses computer models to track changes in the airways of people and animals. When researchers previously developed a computer model of the airflow dynamics in a horse’s airway, they found increased turbulence near the laryngeal opening. Based on those findings, a group of WCVM researchers are working to create a computer model of RLN so they can learn more about equine airways, how turbulence develops in the area and how they can improve surgical treatment.

By gaining further knowledge of this technology, the equine scientists eventually hope to reach the point where they create individual surgery plans that will ensure the best outcome possible for patients afflicted with this disease.

How can a new technique provide real-time pictures of lung ventilation?

Tanya Duke, Maria de Rocio Fernandez Parra, Joe Bracamonte, and Masako Fujiyama, WCVM

During a laparoscopic procedure in a sedated horse, carbon dioxide is insufflated, or blown, into the animal’s abdomen. This process can end up compressing the horse’s diaphragm and reducing its lung function during the laparoscopic procedure. It could also be part of the reason for changes in the equine patient’s blood flow while under sedation.

Electrical impedance tomography (EIT) is a new, non-invasive, and easily applicable method that can be performed in unsedated horses as well as in horses under general anesthesia. By placing a belt consisting of 32 electrodes around a horse’s thorax, researchers can use EIT to gain a real-time, pixelated picture of the patient’s lung inflating and deflating during standing sedation. The electrodes measure the differences in air flow between sedated and unsedated horses, and they also show the specific areas where impedance of the lung may occur.

In this study, WCVM anesthesiologist Dr. Tanya Duke and research team will use EIT to assess lung ventilation in sedated horses during laparoscopic procedures. The technology will help the team develop strategies for preventing the risk of lung compression during anesthesia. As well,  the researchers will gain new skills from using EIT that can be applied to other investigations of lung ventilation and lung diseases.

Can a new protein eliminate breeding-induced inflammation?

Stephen Manning, Dinesh Dadarwal, Kate Robinson, Lea Riddell, WCVM

Endometritis is the inflammation of the uterine wall and commonly happens after a mare has been exposed to semen and bacteria during breeding. Typically, it only lasts about 48 hours before inflammation decreases. But in susceptible mares, ones that are more prone to persistent breeding induced endometritis (PBIE), inflammation can last up to 96 hours.

This condition creates an unsuitable environment for the embryo and hurts its chances of survival. When a mare can’t conceive, it also leads to more breeding attempts that can be costly for her owner. The current treatment of endometritis focuses on clearing inflammation of the uterus. It’s reasonably effective but can often fail to control the inflammation. It’s also an invasive treatment and can leave the mare in some discomfort.

In this study, a WCVM research team will test a glycoprotein called granulocyte colony stimulating factor (G-CSF) as a possible new treatment for PBIE. Previous research has shown that G-CSF increases production of white blood cells, which aids in earlier resolution of uterine inflammation. Administering G-CSF to susceptible mares represents a new, non-invasive treatment of endometritis that would improve mare’s health and welfare as well as save costs by cutting down on unsuccessful breeding attempts.

Is serum amyloid A a reliable biomarker for septic arthritis?

Joe Bracamonte, Elemir Simko, Seiji Yoshimura, and Roman Koziy, WCVM; and George Katselis, U of S College of Medicine

Septic arthritis is a life-threatening bacterial joint disease that can affect the athletic performance of horses of all ages. Early detection of the disease reduces the likelihood of cartilage damage and increases the chances of effective treatment.

However, it’s a difficult disease to diagnose: veterinarians must rely on their clinical examination and biomarkers in the joint’s synovial fluid, but these markers can change after treatment. Current therapies also tend to cause further inflammation, making it challenging for veterinarians to know when they should discontinue treatment.

Serum amyloid A (SAA) is an acute-phase protein that could prove to be a valuable diagnostic and monitoring tool for veterinarians. In previous studies, WCVM researchers found that SAA concentrations in synovial fluid will increase or decrease in parallel with inflammatory activity in a horse, making it a possible biomarker for early disease detection.

In this study, WCVM scientists will experimentally induce septic arthritis in six horses and then aggressively treat them for the condition immediately afterward ­— a research step that hasn’t been tested yet. By tracking changes in the protein’s concentration throughout the treatment process, the team members hope to learn if SAA levels can reliably indicate when the infection is gone.

What’s killing Sable Island horses?

Emily Jenkins and Bruce Wobeser, WCVM; Phil McLoughlin, Dept. of Biology, U of S; Todd Shury, Parks Canada; Trent Bollinger, WCVM/Canadian Wildlife Health Cooperative; and Jocelyn Poissant, University of Calgary Faculty of Veterinary Medicine

Off the east coast of Nova Scotia, Sable Island is home to one of North America’s only populations of wild horses. Since intensive studies began in 2007, researchers have individually identified almost all 500 horses on the island and are using DNA testing to determine their pedigrees.

Results of a 2017 pilot study showed that starvation, parasites, hoof and tooth abnormalities, mineral deficiencies and sand colic contributed to the death of about 10 per cent of the island’s horse population during a particularly harsh winter. Researchers also noted a high prevalence of Dictyocaulus arnfeldi, a lungworm normally found in donkeys, in the lungs of dead horses.

In this next study, researchers will continue examining additional island horses that died during the past winter. The project will include expanded sampling for lung parasites, bacteria and viruses. The researchers will also explore connections between stress and parasites in living horses sampled during the summer of 2018.

Results will shed more light on the causes of death and the role of parasites in natural horse herds. This information can also help the horse industry better understand how to reduce deworming in the face of increasing parasite resistance.

How can an electronic pill provide real-time data of a horse’s gastrointestinal tract?

Julia Montgomery and Joe Bracamonte, WCVM; Khan Wahid, U of S College of Engineering

Just like people, many horses commonly suffer from issues and disorders dealing with their stomach and intestines. But what’s challenging about the horse’s gastrointestinal (GI) tract is its large size, which makes it very difficult for veterinarians to conduct a comprehensive examination. Some sections of a horse’s GI tract, such as the small intestine, are impossible to examine in a standing horse that’s fully awake.

Researchers at the WCVM and the U of S College of Engineering are exploring the possibility of using an electronic capsule called a SmartPill to examine the entire GI tract of an awake, standing horse. The SmartPill, frequently used for examining gastrointestinal issues of humans, will be able to measure temperature, pH, and pressures inside a horse’s GI tract. The researchers are also investigating a similar pill that’s equipped with cameras. The “PillCam” can provide real-time imaging of the inside a horse’s GI tract.

Previous research has shown that when the human version of the SmartPill is used in horses, it has some limitations including gaps in data transmission and an inability to accurately locate the pill in the animal’s small intestine. In this study, the researchers will work to develop an equine version of the SmartPill that’s capable of providing information about the entire equine GI tract — including the small intestine — in an awake, standing horse.