Roaring, or laryngeal paralysis is a common upper respiratory disorder in horses. It is characterized by paralysis of the left arytenoid cartilage and vocal fold. When this one-sided paralysis occurs, the affected flapper is sucked into the airway when the horse inhales, thus obstructing the air flow. A roaring or whistling sound occurs as the horse breathes in and is most evident as the horse begins to exercise.
Diagnosing roaring in horses
Research using ultra sound technology when making diagnosis of roaring may lead to developing an accurate simple way to track the results of treatment without using an invasive biopsy.
With a recent donation from the Equine Foundation of Canada, University of Guelph researcher, Dr. Heather Chalmers, is able to add a new dimension to her research focusing on early screening of roaring and may lead to earlier treatment.
Using ultra sound technology that gives a more detailed picture when making diagnosis of roaring and developing an accurate simple way to track the results of treatment modalities without using a more invasive biopsy, this technoligy is more accurate than a CAT scan.
The goal of Chalmers’ research is to provide horse owners with a reliable, easy, readily available and inexpensive way to screen horses for roaring prior to clinical signs of the disease. This allows horse owners or a potential horse purchaser to career plan for their horses, determining potential or limiting factors. Chalmers’ is very excited about the donation of new equipment this past summer, “When it comes to ultrasound - 3D allows us to look at the tissues in greater detail, to get a more accurate assessment of the size and exact location of abnormalities and to monitor them accurately over time.”
Assessing the size of the upper airway muscles helps researchers understand more about their function and disease status. Chalmers explains, “We know from our own experience, working out in the gym, a muscle that gets bigger is stronger and more functional. After interventions the ultra sound will be able to keep track of changes to see if the smaller diseased muscle has responded with an increase in size.”
The next step in Chalmers’ research is to solidify the long suspected link between what is seen on the ultrasound screen and what can be found under the microscope if a biopsy were performed.
It is important to fully establish:
- How early disease can be detected in horses?
- How accurately it can be done?
- The rate at which the disease progresses once detected?
- Ultrasound is helping researchers understand all three of these questions.
Research funding has been provided by Equine Guelph, American College of Veterinary Radiology, Medel Austria, Robarts Imaging Institute at the University of Western Ontario and The Equine Foundation of Canada.
Funding for the Report on Research and Help for Horse Owners videos has been provided by the Knowledge Translation and Transfer Program under the OMAFRA-U of G Partnership.
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