Days and nights becoming chilly and horses being stabled more frequently can become a flashpoint for lower respiratory tract disease. Vet Lucinda Ticehurst explains the subtle signs to look out for in this year-round problem that can be exacerbated by the dust associated with indoor living
VET NOTES l LOWER RESPIRATORY TRACT
HORSE OWNERS, RIDERS, trainers and vets should all have an understanding of the horse’s respiratory system. A well-functioning respiratory system is essential for an equine’s overall health, performance and wellbeing. Horses are adapted to hide respiratory issues as not doing so would make them vulnerable to predators in the wild. This, however, means that it is vital to remain diligent in detecting a weakness before it progresses to something more serious with long-term effects. Horses have no option but to breathe through their nose — they are obligate nasal breathers — and they should never breathe through their mouths, meaning that sometimes signs of respiratory stress can be subtle.
The primary function of the horse’s respiratory system is the exchange of oxygen for carbon dioxide that takes place between the millions of tiny air sacs called alveoli and the pulmonary capillaries that envelop them. This allows the horse to obtain oxygen for energy production and removes carbon dioxide, a waste product. In addition to gas exchange, the respiratory system helps to regulate the horse’s body temperature by adjusting the rate and depth of breathing.
