A WORLD-class panel of veterinary experts addressed the highly successful Irish Equine Conference, organised by Veterinary Ireland, and held recently at Lyrath estate, Co Kilkenny, where top data and presentations were enjoyed by the attending veterinary community.

With kind permission, we have extracted some of the main points of interest to our readers from the presentations on tendons, stifles, cardiac and back problems.

TENDONS

Professor Roger K.W. Smith of The Royal Veterinary College.

Diagnosis and Management of Tendon and Stifle Injuries

  • Tendon injuries are one of the most common orthopaedic injuries in the horse and affect all athletic disciplines. Injuries can occur as a consequence of trauma but most frequently arise from overstrain. Enlargement and inflammation. Diagnosis by palpation and ultrasound imaging and MRI.
  • After injury, most tendons heal by mounting a fibrotic response characterised by three phases of healing - acute (inflammatory), subacute (fibroplastic) and chronic (remodelling).
  • Acute (inflammatory) phase management: rest, application of cold and compression with bandaging, even a cast, is still simplest and most important aspect of early management.
  • Subactue (fibroblastic) phase: very soon after the injury, fibrous tissue is generated. Restores tissue strength but is less function than original tissue. The aim is to encourage fibroplasia and optimise the functionality of the scar tissue.
  • Controlled exercise programme with regular ultrasonographic monitoring is the mainstay of improving the quality of the scar tissue.
  • Platelet-rich plasma and mesenchymal stem cells can be used to improve the quality of the reparative tissue.
  • Chronic (remodelling) phase: Newly formed scar tissue is still relatively weak. If exercise levels are increased too rapidly, re-injury can occur at the same site.
  • Over time, this scar tissue becomes stronger but also stiffer, tendon always suspecible to re-injury.
  • The aim is to optimise the functionality of the scar tissue and prevent re-injury.
  • A controlled ascending exercise regime with regular ultrasounds to detect signs of re-injury early on provides the best management in these cases
  • Prevention of tendon overload will reduce the risk of re-injury, lower exercise levels. Use fetlock support where possible when exercising.

    • STIFLES

    Stifle is common site of development conditions such as osteochondrosis in the young animals, soft tissue injuries relatively common in adult sport horses.

    Many soft tissue stifle injuries are traumatic in nature, usually from a fall. Lameness is highly variable and is not specific to the stifle.

  • Stifle is responsible for a consideration amount of the protraction phase of the stride, cranial phase of stride often reduced and lameness evident or worse on soft ground compared to hard ground.
  • Diagnosis depends on palpation, diagnostic imaging and diagnostic analgesia (nerve blocking).
  • Cranial, medial and lateral aspect of the stifle should be carefully palpated.
  • Diagnostic analgesia of all three separate stifle joints should be performed in cases where the location of the lameness is unknown.
  • X-rays, gamma scintigraphy and MRI in cases.
  • Osteochondrosis treatment: most common site is the lateral trochlear ridge of distal femur. Diagnosis on X-ray and ultrasound in clinically silent limbs.
  • Treatment is arthroscopic debridement and removal of ossified cartilage flaps. Prognosis is 64-66% for a return to full work.
  • Two possible causes for development of subchondral bone cysts/osseous cyst-like lesions.
  • 1. Manifestation of osteochondrosis with thickened necrotic cartilage persisting as a localised defect within the subchondral bone.
  • 2. Localised trauma damaging primarily either the articular cartilage or the underlying subchondral bone.
  • Can be in young, middle aged and older horses.
  • Present as persistent mild to moderate lameness.
  • Diagnosis relies on intra-articular analgesia of medial femoral condyle (or of all three compartments).
  • Cysts appear as large circular or dome-shaped cysts in medial femoral condyle.
  • Treatment options - conservative management (i.e. six months rest).
  • For young animals, first line treatment is corticosteroid injection of cyst lining either done standing or under general anaethesia.
  • For older horses, where injection has failed, treat by surgical debridement of cyst.
  • When horses hit a fence, trauma to the cranial aspect of stifle is common. Bruising results in haematomata.
  • Meniscal tears best evaluated by X-rays, ultrasonography and arthroscopy.
  • Moderate to severe lameness.

    • CARDIAC PROBLEMS

    DYSRHYTHMIAS IN RACEHORSES

    Professor Celia M. Marr, Rossdales, Suffolk.

    (Dysrhythmias defined as abnormality in rhythm of brain or heart)

  • Atrial fibrillation (cardiac arrhythmia) occurs in all types of horses.
  • As it affects exercise tolerance, it is particularly important in racehorses.
  • Horses may have faded or been pulled-up in a race or worked badly.
  • Chaotic irregularly irregular cardiac rhythm.
  • After exercise, the overall heart rate is rapid and takes a prolonged time to recover.
  • General signs of distress, sometimes visible haemorrhage at the nose.
  • At rest, the rhythm is also irregular but overall rate usually within normal limits, most striking feature is extremely long pauses.
  • Key question is there evidence of underlying structural cardiac disease?
  • Clinical signs suggestive of cardiac murmur include resting tachycardia (rapid heart beat), cardiac murmurs, venous distension, peripheral oedema.
  • Many racehorses with atrial fibrillation will self-correct within 48 hours of onset of arrhythmia.
  • Most horses simply need to be allowed to recover.
  • ECG allows the rhythm to be assessed.
  • In horses with sustained atrial fibrillation, and no underlying cardiac disease, two modes of therapy for rhythm correct are well established.
  • 1. Pharmacological conversion.
  • 2. Electrocardioversion - both have potential harmful effects.
  • Quinidine sulphate used for last 50 years to restore sinus rhythm.
  • Prognosis for horses with minimal heart disease is fairly good provided duration of AF is fairly short (around one month).
  • Transvenous electrical cardioversion (TVEC) often preferred for horse with AF of prolonged duration - involves placing of electrodes under standing sedation.
  • Studies on AF show a recurrence rate of 39% at one year in horses treated for the first time.
  • Horses with dysrhythmias at rest and exercise with a history of collapse, distress or epistaxis are more likely to have clinically significant cardiac disease.
  • It is now possible to record a resting equine ECQ using a clipless device attached to a smart phone.
  • Given that many equine dysrthythmias occur on the racecourse, it is very helpful if the rhythm can be characterised immediately.
  • Exercise ECG is a central component of the diagnostic work-up in any racehorse suspected of having heart disease.
  • Treadmill exercise is perfectly appropriate but nowadays more usual to record the ECG overground.
  • Telemetric devices allow ECG to be viewed in real-time or ECG can be left with trainer so that multiple work sessions can be recorded.
  • This can increase the likelihood of their detection as equine rhythm disturbances are transient.

    • BACK PAIN

    Diagnosis and management of back pain, Dr Sinead Devine, DVM MVB CVMA, UCD Vet Hospital.

    Back pain a common problem in horses which can be frustrating to both diagnose and treat. Neck or back problems and lameness are often interrelated.

  • Vertebral column runs from atlanto-occipital joint to last coccygeal vertebra.
  • Reaches its lowest point at the cervicothoracic junction - a suspension bridge between thoracic and pelvic limbs, which supports weight of rider.
  • Muscular support is provided dorsally by the epaxial muscles.
  • History in back pain cases may vary including:

    • • cold backed/girthy, poor performance, reduced flexibility

    • vague lameness or lame only when ridden

    • stiff or slow to warm up, refuses jumps, resists collection

    • difficulty turning one direction

    • switching leads behind at canter

    • many other signs often attributed to bad behaviour

  • An extensive physical exam should include a lameness work-up and neurologic exam if indicated.
  • Inspection of conformation and postural analysis, then gait analysis and evaluation of tack and rider.
  • A Diagnostic Acupuncture Palpation Exam proven to be useful in identifying pain in topline and specific point sensitivies can suggest pain from certain distal limb areas.
  • Motion palpation of the spine can help localise a lesion and/or determine severity.
  • Hypomobility, characterised by restricted joint motion, can be caused by local muscle spasms, connective tissue fibrosis, osteoarthritis, dorsal spinous process impingement and ankylosis.
  • This can in turn lead to a “pain–restricted Range of Motion” cycle.
  • Imaging follows a complete physical exam.
  • X-rays used to diagnose kissing spines.
  • Nuclear scintigraphy very useful imaging tool.
  • Ultrasound most commonly used for ultrasound-guided injections.
  • Treatment of back pain can include acupuncture, massage, chiropractic and laser therapy.
  • The “bone out of place” concept is not supported by current research.
  • Clinically it seems cases of primarily back stiffness respond to chiropractic, stretching and massage.
  • Cases of more acute back pain – acupuncture and laser therapy are beneficial.
  • Mesotherapy works on the “Gate control theory of pain” - can aid in stopping the pain spasm cycle.
  • Bisphosphonates commonly used for both thoracolumbar and sacroiliac pain.
  • Shockwave therapy also used.
  • Long-term management of back pain dependant on accurate diagnosis and treatment.
  • Rider influence, saddle fit and training regimes, specifically core strengthening, are critical to rehab.