RESPIRATORY DISEASES IN HORSES
EPIDEMIOLOGY OF RESPIRATORY PROBLEMS
Respiratory diseases can be considered as the second most common cause of loss of performance in sport horses and racehorses after musculoskeletal problems. The overall prevalence of respiratory diseases is most probably underestimated due to the fact that some chronic forms of diseases may develop sub clinically, although they still impede performance.
LOWER AIRWAY ISSUES
Intensive training, repeated transports and mingling during competitions may also promote the development and transmission of infectious diseases. Whatever the type of sport, most lower airway diseases cause a significant decrease in athletic parameters and delayed cardio-respiratory recovery. The main lower respiratory diseases involved in poor performance reported are inflammatory airway disease (IAD), recurrent airway obstruction (RAO), exercise induced pulmonary haemorrhage (EIPH) and viral or bacterial infections. Several factors inevitably promote the occurrence of inflammatory diseases, such as age (higher prevalence in older individuals), pollution and other environmental conditions. Horses are often housed indoors in buildings were ventilation within the boxes is limited, indoor storage of hay and straw can be encountered and doors and windows are often closed during the cold months. This type of management promotes chronic respiratory inflammation.
Intensive training, repeated transports and mingling during competitions may also promote the development and transmission of infectious diseases.
Moreover, competition itself is also a key factor in the prevalence of lower airway diseases in horses. Competition may trigger metabolic and hormonal alterations, which disturb immunity. Depression of the immune system and the occurrence of repeated inflammatory and oxidative processes during training and competitions seem to create favorable conditions to the outbreak of infectious respiratory diseases. These respiratory problems are often subclinical but have an impact on performance and may impede the pursuit of their physical preparation as well as post-race short and long-term recovery.
EXERCISE-INDUCED PULMONARY HAEMORRHAGE (EIPH)
Exercise-induced pulmonary hemorrhage (EIPH) is a unique respiratory condition that results in the shedding of blood in the lungs and airways after a sufficient strenuous exercise. Pulmonary hemorrhages have been shown to be associated with pulmonary inflammation and fibrosis, gas exchange disturbances during exercise and subsequent poor performance. EIPH can also affect negatively the duration of the career of sport horses and race horses.
In practice, the diagnosis is generally made by observation of:
> POST-EFFORT EPISTAXIS (bleeding from the nose)
> BLOOD WITHIN TRACHEA AND LOWER AIRWAYS
However, in most cases, the blood remains within the lungs and diagnosis can only be made through sampling of the lower airways.
RACE HORSES: Prevalence as high as 95% has been reported.
EVENTING, POLO, AND EVEN HIGH-LEVEL SHOW-JUMPERS: In all disciplines including intense or fast bouts of exercise, horses have been diagnosed with EIPH. Recent study revealed that the incidence of EIPH in show-jumpers – participating at 4 and 5 star competitions – can go up to 50%.
ENDURANCE, DRESSAGE AND LEISURE: Lower prevalence.
- Age and gender
- Type and distance of the race
- Intense or fast bouts of exercise
- Hardness of the ground and presence of jumps
- Air temperature
- Pulmonary inflammation
There is a need for an effective, non-doping prophylactic treatment to prevent the occurrence of EIPH in competitive horses.
CONSENSUS STATEMENT ON EIPH BY THE AMERICAN COLLEGE OF EQUINE INTERNAL MEDICINE
Based on the current scientific evidence, EIPH should be considered a disease, as it is progressive and can significantly reduce lung capacity.
> Furosemide is currently the only effective treatment for the management of horses with EIPH. However, because of its ergogenic effects, furosemide is banned from use in competitions by racing jurisdictions in Europe, Asia and Australia as well as by the FEI.
CLINICAL TRIAL: Bronchix Pulmo
Investigators: Dr. Emmanuelle van Erck-Westergren / Dr. Fe ter Woort
Equine Sports Medicine Practice, Waterloo, Belgium
> PRODUCT STUDIED
A food supplement, specifically formulated to strengthen blood vessels, improve tissue elasticity and maintain airway patency.
> AIM OF THE STUDY
Determine the effect of a daily oral supplementation of Cavalor Bronchix Pulmo over the period of one month on the incidence and severity of EIPH in active racehorses.
Sixteen Thoroughbred racehorses in active training and racing were involved in the trial.
- Aged 2-9 years old (11 geldings, 5 mares)
- All from the same stable: managed similarly
- Feed, work and environmental management remained identical during the trial
- None of the horses received any treatment during the course of the study
SUPPLEMENTATION PROTOCOL CAVALOR BRONCHIX PULMO
All horses were supplemented every day for 25 days.
- 23 DAYS: 20cc / horse / day for 23 days
- DAY 24: 30cc / horse / the evening prior to the second exam on day 24
- DAY 25: 60cc / horse / on the day of the second exams on day 25
INITIAL EXAMINATION AFTER RETURNING FROM A TRAINING SESSION AT THE GALLOPS, PRIOR TO SUPPLEMENTATION
Horses were scoped and scored for:
- Pharyngeal lymphoid folliculitis
- EIPH/Tracheal mucus
- Carina thickness
- Tracheal wash and broncho-alveolar lavage
Tracheal wash (TW) and broncho-alveolar lavage (BAL) were also sampled for white (WBC) and red blood cell counts (RBC) and cytology.
ALL EXAMS WERE RE-ITERATED IN THE SAME CONDITIONS AFTER 25 DAYS OF DAILY ORAL CAVALOR BRONCHIX PULMO SUPPLEMENTATION
Were considered as having EIPH:
- Endoscopy scores 1-4/4
- Presence of red blood cells in the TW and BAL
TW and BAL, also sampled for WBC, RBC and cytology at T2.
> 15/16 THOROUGHBRED RACEHORSES WERE DIAGNOSED WITH EIPH
T1 / T2: Data were analyzed using Wilcoxon signed-rank test. Significance was set for p<0.05
EFFECT OF SUPPLEMENTATION ON RESPIRATORY HEALTH
This study demonstrated that the use of daily Cavalor Bronchix Pulmo oral supplementation during a 25 day period significantly reduces the incidence and severity of EIPH in Thoroughbred racehorses during a period of intensive training. Non of the horses studied bled at T2. The results also show that Cavalor Bronchix Pulmo has a mild anti-inflammatory effect and reduces signs of inflammation in the lower airways.
Cavalor Bronchix Pulmo is an oral supplement that can be given to horses as a preventative measure to avoid the occurrence of EIPH.