IN recent weeks there has been a lot of focus on Tepin, the top American racehorse, best known for winning the Breeders’ Cup Mile in 2015, and the issues she will have to overcome when taking part in next week’s Royal Ascot Queen Anne Stakes, where she is a general-priced 4/1 favourite.

Tepin is known to have a breathing problem which is managed by her trainer through the use of nasal strips during exercise and furosemide, more commonly known as Lasix.

Both Lasix and nasal strips are banned from racing in Ireland and the UK. Nasal strips are permitted in FEI Showjumping and eventing competitions but are strictly prohibited in dressage. Furosemide is classified as a controlled medication on the FEI Prohibited Substances list.

Tepin’s connections were quite concerned about running the mare at Ascot, without Lasix or nasal strips, after working the mare recently without them and reporting that the mare made “maybe a little bit more” breathing noise than normal.

A number of other high-profile, equine athletes including Nyquist, winner of this year’s Kentucky Derby, Michael Jung’s Fischerrocana FST, winner of this year’s Rolex Kentuckey Horse Trials and Denis Lynch’ Ho Go van de Padenborre, to name but a few all wear nasal strips. The use of these nasal strips is becoming ever more prevalent in equestrian sport, but what is the reasoning behind it? This week I spoke to the experts to try and find out why.

EIPH

The occurrence of EIPH is multi-factorial. Neil Mechie, veterinary surgeon at Mark Johnston racing listed a number of these factors in a recent Hands On article:

  • One is that it is caused by a failure in the integrity of the walls of pulmonary capillaries (small blood vessels in the lungs) due to the excessive stress of high blood pressures within the blood vessels and low pressures in the chest during exercise. The lungs act to facilitate oxygen exchange between environmental air and the blood. For this reason, the walls of the blood vessels and lung lining are very thin, predisposing them to bleeding during strenuous exertion. Although generally accepted as the most likely cause of EIPH, this theory does not explain the location or progression of the disease.
  • Another theory is that locomotory forces generated by the forelimb and the weight of the abdominal contents cause damage to the fragile blood vessels of the lungs, causing blood to accumulate within the airways.
  • EIPH is commonly accompanied by airway inflammation, as seen when the lungs are examined via endoscopy and lung fluid samples are analysed. But the role of inflammation in EIPH is unclear, and it is not understood whether inflammation acts as a predisposing factor or appears secondarily as a result of EIPH.
  • Other causes of blood in the airways include fungal infection of the guttural pouches, ethmoid haematomas within the nose, pneumonia and atrial fibrillation of the heart. These causes of blood in the airways should be ruled out when the veterinary surgeon carries out their investigation as to the source of blood in the airways.
  • Upper respiratory tract dysfunction, whether it is nasal, pharyngeal or laryngeal, creates increased resistance to airflow and can exacerbate EIPH. It is possible that EIPH is a multifactorial syndrome and several factors must be taken into consideration when managing horses that bleed.

    • Marie Harty, veterinary surgeon at Anglesey Lodge Equine Hospital added that: “Trauma caused by concussion or the impact of the jockey on the horse’s back could also lead to pulmonary haemorrhage.” Marie also noted that: “more National Hunt horses seem to suffer from this condition than flat horses.”

    A number of clinical studies have been carried out where horses were exercised on a high-speed treadmill, without the presence of a rider, and bleeding still occurred. A rider may exacerbate the condition, but bleeding can still occur without the presence of a rider.

    MANAGING EIPH

    The equestrian world became widely aware of EIPH in the 1960’s, when Northern Dancer was treated with Lasix and won the Kentucky Derby, but how far have we come in our understanding of the condition and our ability to provide horse owners with safe and effective management options that are allowed across all areas of equestrian sport?

    At present, careful management of the horse’s environment and the horse’s fitness training are the only options available to all horse owners.

    Fungal poisoning can lead to EIPH, feed or bedding can be contaminated with toxins produced by various types of fungi.

    The Irish Equine Centre provides an environmental testing service. They have personnel out on the road, calling to mainly racing and some show jumping yards, checking all the environmental conditions.

    They will look at the ventilation, taking samples of everything from the food, hay, haylage, the bedding the horses are on. They look for aspergillus and mycotoxins, metabolites produced by fungi, which can be dangerous to horses’ health above a certain level.

    Environmental management plays an important part in increasing lung health and good ventilation is vital to prevent dust and remove humid conditions.

    Careful fitness training is also important, the horse should be built-up slowly and not be put under excessive stress or strain.

    When designing a fitness programme for your horse you need to consider the horse’s age, present level of fitness, soundness and whether the horse has any previous respiratory issues.

    Some horse owners may consider using a nebuliser on their horses. This can enable the delivery of nebulised natural therapies directly to the airways of the horse.

    When asked about using nebulisers as a preventative measure for EIPH, Marie Harty replied: “I would advise horse owners to be very careful about using nebulised herbal therapies and products of which the ingredients are unknown.

    The use of any substance to affect the performance of a horse can have very serious ramifications.”

    DIAGNOSING EIPH

    It was mentioned earlier that blood is sometimes evident discharging from a horse’s nostrils due to EIPH, however this usually only occurs in a small percentage of bleeders.

    For those that do not exhibit blood discharging from the nostril other clinical signs include:

  • Taking longer to return to resting respiratory rates (8-12 inhalations a minute)
  • Coughing after exercise
  • A small amount of pulmonary haemorrhage may or may not significantly reduce performance but a larger amount of bleeding will be likely to impact on it

    • If EIPH is suspected you should contact your veterinary surgeon straight away. Marie Harty explained that “If blood is not visible at the nostrils the vet will usually perform an endoscopic examination (scope) and possibly a tracheal wash or bronchoalveolar lavage.”

    The scope allows the vet to check for inflammation and where necessary to administer an appropriate treatment. A bronchoalveolar lavage takes a sample from the lung, where the problem is originating, alerting the vet to any infection.

    The vet can then prescribe an appropriate method of treatment. A horse that has suffered from EIPH will require a period of rest and sometimes antibiotics or inhaled corticosteroids. Exercise is then gradually increased and lung health monitored by repeated endoscopic examination.