Page 167 - The Veterinary Care of the Horse

LABORATORY TESTS

Blood tests may be taken to check the overall health of the horse or specifically to check
VetBooks.ir muscle enzymes to see if any muscle damage has occurred. Conditions such as exertional

rhabdomyolysis syndrome (azoturia) can make a horse appear stiff and slightly sore or
suddenly and acutely lame. Muscle enzyme levels can be helpful in confirming the diagnosis.

Other laboratory tests are sometimes performed including a muscle biopsy to check for

diseases such as polysaccharide storage myopathy (PSSM) or equine motor neuron disease.

NERVE BLOCKS

Nerve blocks are often used to confirm a diagnosis or to localize the problem when the

source of lameness is not obvious. Injection of a small amount of local anaesthetic around a
sensory nerve will cause the area it supplies to become numb. If the horse becomes sound

following the injection, then the source of the lameness is in the area that has been
desensitized. The usual procedure is to start at the foot and work upwards. Local anaesthetic
may be injected:

• around a specific nerve

• into a joint space or other synovial structure such as a tendon sheath
• locally, e.g. around a splint or the origin of the suspensory ligament.

DIAGNOSTIC IMAGING

The following diagnostic imaging techniques may be used to give further information about

the source of the lameness.
• Radiography (X-rays).

• Ultrasonography.

• Scintigraphy (bone scan).

• Magnetic resonance imaging (MRI).
• Computed tomography (CT)

• Thermography.

FURTHER INVESTIGATIONS

On occasions, arthroscopy is used as a diagnostic tool. This procedure allows direct
inspection of joint surfaces.

Making a diagnosis