Nerve Blocks Explained: How We Diagnose Lameness

Lameness can be one of the most frustrating issues for horse owners. Sometimes the signs are obvious, but in many cases lameness can be subtle or difficult to localise.

Nerve blocks are a valuable diagnostic tool that help your vet accurately identify the source of pain so that appropriate treatment can begin.

What Are Nerve Blocks?

A nerve block involves injecting a small amount of local anaesthetic around a specific nerve or joint to temporarily numb sensation in that area.

If the horse’s lameness improves after the area is numbed, this indicates that the source of pain is within that region.

Nerve blocks are used for diagnosis, not as a long-term treatment.

Why Are Nerve Blocks Needed?

Lameness can originate from many structures within the limb, including:

• Hooves

• Tendons and ligaments

• Joints

• Bones

• Soft tissues

Because pain can be referred or compensated for, imaging alone may not always pinpoint the cause. Nerve blocks help narrow down the exact location of pain.

How Are Nerve Blocks Performed?

The procedure is usually carried out during a lameness examination and involves:

1. Assessing the horse in hand and/or under saddle

2. Cleaning the skin thoroughly

3. Injecting a small amount of local anaesthetic

4. Waiting a short period for the anaesthetic to take effect

5. Re-assessing the horse’s movement

This process may be repeated, starting low in the limb and moving higher, until the source of pain is identified.

Is the Procedure Safe?

Yes. Nerve blocks are a routine and safe diagnostic procedure when performed by a qualified vet.

Your horse may:

• Feel minimal discomfort during the injection

• Experience temporary numbness in the area

• Be slightly unsteady immediately afterwards

The effects of the anaesthetic wear off within a few hours.

What Happens After a Nerve Block?

Once the painful area has been identified, your vet may recommend:

• X-rays or ultrasound of the affected area

• A treatment plan tailored to the diagnosis

• Rest, rehabilitation, or physiotherapy

• Medication or further investigations if needed

Accurate diagnosis helps avoid unnecessary treatments and reduces recovery time.

Will My Horse Need Sedation?

Some horses tolerate nerve blocks very well, while others may benefit from light sedation to ensure the procedure is carried out safely and calmly. Your vet will discuss this with you beforehand.

Why Accurate Diagnosis Matters

Treating lameness without identifying the cause can lead to:

• Prolonged discomfort

• Recurrent lameness

• Wasted time and cost

Nerve blocks allow targeted treatment, improving outcomes and long-term soundness.

In Summary

Nerve blocks are an essential diagnostic tool used to accurately identify the source of lameness. They are safe, effective, and help guide appropriate treatment and management decisions.

If your horse is showing signs of lameness or reduced performance, your vet can advise whether a lameness examination and nerve blocks are appropriate.