Respiratory Health in Horses
Professor Jo-Anne Murray
PhD, MSc, PgDip, BSc (Hons), BHSII, RNutr, PFHEA University of Glasgow Veterinary School
Respiratory Health & Performance
With horses being performance animals, whether it be for athletic or draught work, maintaining respiratory health is crucial. Over the years many scientific studies have tried to determine the links between respiratory disease and performance. These studies have often been in Thoroughbred racehorses given the levels of athletic performance that they achieve and the financial impacts of performance. In fact, some studies have gone on to report that in young Thoroughbred racehorses respiratory disease can be the most common medical condition that affects them, and overall it appears that respiratory disease in performance horses such as Thoroughbreds, Standardbreds and Quarterhorses is more common than originally thought. It is often difficult to observe clear links between specific diseases and performance, but it does appear as if diseases such as Exercise-Induced Pulmonary Haemorrhage (EIPH) does increase the likelihood of inferior performance possibly leading to a shortened career, with negative impacts on placings and indeed earnings where these are applicable. Although much of our knowledge comes from research studies, and our experiences of working with Thoroughbred racehorses, it is important to recognise that respiratory disease can have negative effects for any breed/type of horse in work.
Respiratory diseases in horses are very common and can have a variety of causes, often grouped as infectious (e.g. bacterial and viral infections; such as Strangles) and non-infectious (e.g. hypersensitivity to allergens/inflammatory airway disease; such as Equine Asthma). There are some others that don’t quite fit within the groupings such as EIPH. In recent years our knowledge of how some of these non-infectious respiratory diseases affect the horse during exercise has really improved through the use of dynamic endoscopy. Dynamic endoscopy essentially uses a ‘scope’ that remains present within the horse during ridden exercise, resulting on vets being able to view ‘dynamic’ real-time videos of the horse’s respiratory tract when it is exercising intensely. This has been incredibly valuable and lets us understand more about what is going on in the lungs. There are various signs to look out for that may indicate your horse has some sort of respiratory disease. These can include, but are not limited to, signs such as coughing, a persistent runny nose, a higher breathing rate (than you would expect), an increased temperature, a slower recovery time following exercise, frequent swallowing during exercise, and blood at the nostrils (sometimes called epistaxis) during or after exercise. Obviously, some horses may only have one or two symptoms, while others may have several symptoms, which can vary due to the underlying cause.