The Link Between Poor Performance and Medical Issues

Why “just not himself” might mean it’s time to investigate

We often hear from owners or riders who say their horse is “just not going as well". Maybe they’re lacking impulsion, feeling stiff, becoming grumpy under saddle, or refusing to work the way they used to. While it’s easy to assume this is down to training, fitness, or behaviour, poor performance is often the first sign of an underlying medical issue.

Why Performance Matters in Diagnosis

Horses are athletes, and even small issues can affect how they move, behave, and perform. A dip in performance is not always due to a lack of training or rider error. In many cases, it’s the horse’s way of saying something isn’t right.

By looking beyond behaviour and asking why performance has changed, we can often identify problems before they become more serious.

Common Medical Causes of Poor Performance

1. Lameness or Subtle Pain

Low-grade lameness or asymmetry can feel like a loss of balance, impulsion, or straightness.
Saddle discomfort or sore feet (e.g. thin soles, bruising, navicular changes) may show up only under certain conditions.
Back pain or sore sacroiliac joints are commonly missed early on.

2. Gastric Ulcers

Horses with ulcers often show vague signs: girthiness, resistance to work, irritability, or inconsistent performance.
Gastroscopy is the only way to confirm a diagnosis — and treatment is usually very effective.

3. Respiratory Conditions

Poor stamina, coughing, or heaviness in the contact could be signs of airway inflammation or mild asthma.
Endoscopy or airway washes can help pinpoint the issue.

4. Cardiac or Metabolic Conditions

Irregular heart rhythms or underlying metabolic disorders (like EMS or PSSM) can affect energy levels and recovery.
Blood testing and exercise tests are useful in these cases.

5. Dental Pain

Sharp points, loose teeth, or bit-related discomfort can interfere with contact, head carriage, and relaxation during work.

6. Hormonal Imbalances

Cushing’s (PPID) or other hormonal shifts in older horses can cause muscle wastage, lethargy, or behavioural changes.

What Does a Poor Performance Work-Up Involve?

When you book a poor performance investigation, your vet will tailor it to your horse’s history, workload, and symptoms. It may include:

A detailed physical and lameness exam (including ridden assessment)
Flexion tests, nerve blocks, or trot-ups
Assessment of back/neck pain
Gastroscopy (for ulcers)
Endoscopy or respiratory testing
Blood tests (to check muscle enzymes, liver/kidney function, infection, or hormonal levels)
X-rays or ultrasound if needed

This holistic approach helps uncover hidden issues and rule out potential causes — and it’s often the key to getting your horse back on track.

It’s Not Just Behaviour

Before you blame your horse for being “naughty,” “lazy,” or “difficult,” ask yourself:

Has their performance changed?
Are they reluctant to work in ways they previously enjoyed?
Do they feel different under saddle — even if not obviously lame?

If the answer is yes, a vet check is always worthwhile.