Lameness Investigation

Full facilities for assessment

Lameness investigation forms a major part of the work of Rainbow Equine Hospital for both first opinion, second opinion, and referral clients. Although initial assessments and simple lameness can often be diagnosed and treated at the stable or yard, more complicated lameness cases are best brought to Rainbow Equine Hospital. We have excellent facilities for trotting horses up and both hard and soft surfaces for working horses on a circle. We are able to observe horses under saddle in the all weather arena which allows us to perform a complete clinical assessment prior to further diagnostic tests.

Following a full history and clinical examination, these tests may include nerve blocks, radiography and/or ultrasonography. Some complex lameness cases may require the use of scintigraphy or bone scanning, and many horses are referred specifically for this service. While radiography and ultrasonography can provide good anatomical detail scintigraphy works by measuring the metabolic activity within the bone and it is therefore a much more sensitive technique which can help us to pinpoint problems long before they become visible on x-ray. This is particularly useful in competition horses that may have suffered a stress fracture.  Scintigraphy is also useful in investigation of multi-limb lameness and particularly back and pelvic problems.

MRI

The latest addition to our ability to image the lower limbs of horses is the installation of a new Hallmarq standing MRI scanner. MRI is an excellent tool for evaluating the structure within the foot, however it can be used to image structures up to and including the knee and hock. The Hallmarq MRI Scanner is located in a purpose designed building on the main equine hospital site. Our specialist team of vets has been trained to use the scanner and interpret the resulting images to the highest standard.

How can MRI help

When a vet examines a horse’s lameness, one of the first steps is often to trot the horse up using nerve blocks to narrow down where the pain is coming from. This might then be followed by X-ray or ultrasound examinations of the suspected area. However, since these imaging tools only show bone (x-ray) or some soft tissues (ultrasound) it is common to not be able to see anything significant.

In such cases a standing MRI can save time, money and worry through an early, safe and accurate diagnosis.

Early – because as soon as the nerve blocks confirm the location of the problem, you can ask your vet for an MRI to help reach an accurate diagnosis. There’s no need to spend money trying different treatments and then MRI in 3 – 6 months’ time as a last resort.

Safe - because the Hallmarq system offers the choice of standing MRI, so your horse does not have to undergo the risks of general anaesthesia for the examination

Accurate - because if nothing is found by X-ray or ultrasound you would have to rely on a judgement not a positive diagnosis. A standing MRI examination offers a 90% likelihood of conclusive diagnosis.

A standing MRI will help you differentiate which cases merit treatment and which don’t. There is no need to treat an unknown problem by trial and error- MRI can give you the facts you need to make definite decisions about your horse’s care.

MRI needs to be used as part of a clinical examination protocol and at the appropriate stage. Consider MRI in the following cases:

  • Chronic lameness has been localised to the foot or in the distal limb by nerve block
  • Radiographs are negative or equivocal
  • Nuclear scintigraphy is being considered – or is negative
  • Access by ultrasound is difficult or impossible
  • After acute onset of lameness during exercise
  • There is a penetrating injury needing urgent attention
  • If treatment and healing need to be monitored before returning to work

What’s involved in an MRI scan?

The Hallmarq Standing Equine MRI uses a strong magnetic field to produce pictures of the soft tissues and bone of the foot and leg. This is non-invasive and completely harmless to the horse.

Light sedation is used to make sure the horse does not move throughout the procedure. The scan itself takes around 1-2 hours and you will be able to pick your horse up later the same day.

The shoes will need to be removed from either both front or both back feet, depending on which foot is being scanned.  We can arrange this at the clinic or you can ask your farrier to do it before your horse arrives.

Each scan produces up to 500 separate images, so interpretation takes time. We will send the images to your vet/our image reader and you should receive the diagnosis in a few days.

Once a diagnosis has been reached, a horse can receive the appropriate treatment. In the case of stress fractures, this is simply may be box rest for 6 – 8 weeks before re-assessment. Other lameness problems may require medication, either orally or into the joint, or the use of shockwave therapy to encourage healing. Results of the lameness investigation may indicate that surgery, such as arthroscopy is required for the removal of damaged tissues from joints.

For further details about our facilities and services please contact us.