Lameness and poor performance

A clinical examination of the horse to assess any areas of heat, pain or swelling by careful observation, palpation and manipulation can help to identify which area may be causing the problem. This is combined with assessing the horse in motion, often in hand in a straight line and on the lunge and sometimes under saddle. Again, this can give valuable information to help pinpoint where the lameness has originated from.

If, following examination and gait assessment, it is still not possible to pin-point the lameness, nerve blocks may be used to help decide on the location. Local anaesthetic is injected either directly into a joint (under sterile conditions) or around a nerve. This will numb the joint or the area sensitised by the nerve below the point of injection. Once the painful area is numbed, the horse should become sound and the area giving rise to the lameness can be located.

We have several methods of imaging available to us and your vet will decide on the one(s) most appropriate for your horse’s needs.

• Ultrasound scanners – We have an in-house ultrasound scanner and two portable scanners. These are invaluable for assessing soft tissues, particularly the integrity of tendons and ligaments and in some cases for assessing the surface of bones. We also have an extra probe for increased tissue depth.
• X-ray – This is for assessing the bones of the limbs, head and spine and is useful not only in diagnosing fractures, but also in evaluating arthritis and laminitis. We have an in-house x-ray machine and two state of the art, portable Eklin machines, which we can take out on the road.
• Bone scan (scintigraphy) – There are some instances where a full body scan is necessary to help find the cause of a lameness, for example where the lameness is too high up the limb to nerve block or when the tissues involved are too thick to x-ray. Bone scan involves injecting the horse with an isotope and taking images of the horse two hours later with a gamma camera. The isotope attaches to bone building blocks and emits a louder signal in areas of high bone turnover (such as in arthritis or fracture repair). These louder signals appear as ‘hot spots’ when imaged with the gamma camera. Horses having bone scans need to stay with us for 2 days and must be booked in advance, in order to order the isotope.
• MRI – In some cases, MRI is needed to precisely and quickly localise damage to a particular soft tissue or bony structure. This can enable more specific, targeted treatment therapies and rehabilitation regimes. A standing MRI will take on average two to three hours and is a non-invasive procedure. Generally, your horse will remain with us at the clinic for the day whilst the MRI is performed, images are interpreted and an appropriate treatment plan formulated and discussed.

It is important to remember that a lameness work up may need to include any combination of these tools in order to get to the bottom of it!

Our typical approach to evaluating a lame horse would be:

• The history of the onset and progression of a lameness is often the most important part of the examination.
• Initial walk and trot and clinical examination of the limbs including palpation and testing the feet with hoof testers.
• Examination on different surfaces and on the circle.
• Examination under saddle.
• Flexion tests and nerve blocks.
• X-ray, ultrasound examination,scintigraphy,MRI are all used to investigate lameness.
• Lameness vs gait abnormality and possibility of neurological causes.

The investigation can take time and the vet may need to repeat the examination or nerve blocks to pinpoint the area of pain.

Once the diagnosis is complete, then a range of therapies are available. They range from rest to controlled exercise, cold water spa, anti-inflammatory medication, intra-articular treatments, regenerative therapies and corrective shoeing.