Late winter/early spring is the time of year when those of us with the competitive urge start planning for the upcoming season of competitions. Top of mind is generally conditioning, schedule planning, and diet to ensure our horses are in peak performance shape come spring. But let’s not forget about the importance of addressing our horses from the inside out to make sure that there aren’t underlying issues that are going to rear their ugly head once competition season arrives. As many of you know, Dr. Penttila competes at a high level on her barrel horse so we’re going to share with you some tips and tricks from our veterinary team on how we keeps her horses in top form. In this post we will discuss our horses’ respiratory health!
Similar to all mammals, the respiratory system is the location of oxygen and carbon dioxide exchange from the air to the blood cell which then provides oxygen to the cells for cellular metabolism and performance during exercise. The difference is the horse’s respiratory system is adapted to make them super athletes with a HUGE capacity for oxygen exchange that is in excess of even animals of similar size. At rest, the horse’s ventilation rate is approximately 80L of air per minute but with exercise this can increase by a staggering 10-fold to 1,800L of air per minute! This provides them with an extraordinary capacity for oxygen exchange that provides the basis for their superior endurance and speed which makes them such fantastic athletes. However, you can imagine that with this system being so important, even a small amount of inflammation or disease can have a big effect on their performance.
Like all animals, horses can be affected by infectious respiratory disease that may cause anything from a slight cold or flu to more extensive pneumonia. While not 100% protective, early season vaccination for the most common respiratory diseases (equine herpes or rhino virus, influenza virus, and strangles) can help to reduce the incidence of infection and the severity if it occurs. Decreasing disease severity is a huge part of helping keep these horses performing because for every day of fever, they typically require at least a week of rest for return to prior exercise performance level.
Figure 1: Horses have very large airway capacity with an average of 55L of capacity at any given time, but respiratory disease such as Exercise Induced Pulmonary Hemorrhage (as seen on the right here) can significantly reduce their respiratory capacity, function, and general performance.
Alternatively, horses can also suffer from non-infectious respiratory disease. This can be divided into upper respiratory tract dysfunction (e.g. Roarer’s) or lower respiratory inflammatory disease (e.g. Equine Asthma or Bleeders). Typically horses with upper respiratory tract dysfunction will have poor performance that is associated with noise during exercise. These conditions usually come from some sort of nerve dysfunction in the upper airway where part of the airway collapses either at rest or during exercise limiting oxygen intake. They can be diagnosed by upper respiratory tract endoscopy, either at rest or during exercise with a dynamic scope. Depending on the type of condition identified, treatment may then consist of surgery or some other intervention to correct the noted abnormality.
Lower respiratory tract conditions can be harder to notice. In mild cases of equine asthma or exercise induced pulmonary hemorrhage (EIPH or Bleeders), there may be no significant clinical signs other than decreased performance. In cases of moderate disease, we may notice coughing during/after exercise, delayed recovery time or heavy breathing during/after exercise, occasional nasal discharge, or nose bleeds. Diagnosis of these conditions may also include an upper respiratory tract endoscopy but also will likely include a bronchoalveolar lavage or BAL procedure. This procedure is done under standing sedation and a tube is introduced into the airway to wash a small amount of cells from the lungs that are then submitted to a laboratory to diagnose the type of inflammation present and identify any evidence of past bleeding or hemorrhage. Once the report is received, we can then provide a unique and targeted treatment plan for that horse to help address the noted inflammation and facilitate any medication or management changes needed to help get that horse back to their top respiratory function and performance!
Figure 2: An upper respiratory tract endoscopy and bronchoalveolar lavage (BAL) being performed in a horse under standing sedation to identify potential respiratory disease.
Lower respiratory tract conditions can be harder to notice. In mild cases of equine asthma or exercise induced pulmonary hemorrhage (EIPH or Bleeders), there may be no significant clinical signs other than decreased performance. In cases of moderate disease, we may notice coughing during/after exercise, delayed recovery time or heavy breathing during/after exercise, occasional nasal discharge, or nose bleeds. Diagnosis of these conditions may also include an upper respiratory tract endoscopy but also will likely include a bronchoalveolar lavage or BAL procedure. This procedure is done under standing sedation and a tube is introduced into the airway to wash a small amount of cells from the lungs that are then submitted to a laboratory to diagnose the type of inflammation present and identify any evidence of past bleeding or hemorrhage. Once the report is received, we can then provide a unique and targeted treatment plan for that horse to help address the noted inflammation and facilitate any medication or management changes needed to help get that horse back to their top respiratory function and performance!
Figure 3: Horses with equine asthma may be treated with a specially designed equine inhaler to help reduce airway inflammation and encourage return to performance.
If you are interested in equine respiratory health or think your horse may be affected by one of these conditions stay tuned for an exciting event to come at Burwash that will provide a deeper dive into the horse’s respiratory health and function and a live demonstration of the above described procedures! In the meantime, don’t hesitate to contact us if you have specific concerns that we can help address for your horse going into performance season.