NAVIGATING THE PRE-PURCHASE EXAM

Buying a horse is a significant investment, both emotionally and financially. A pre-purchase exam (PPE) is an essential step in the buying process to ensure you are making a well-informed decision. This veterinary examination comprehensively assesses the horse’s health and soundness, helping you identify potential issues before finalising the purchase.

The importance of a pre-purchase exam

A pre-purchase exam is not a pass-fail test but rather a detailed evaluation of the horse’s current health status. It offers valuable insights into the horse’s physical condition, identifying any existing or potential health problems that could affect his suitability for the intended use. The findings can influence your decision, negotiation terms, and future management plans for the horse.

Components of a pre-purchase exam

1. History and use assessment: The exam begins with a discussion about the horse’s history, including his medical background, training, and intended use.
2. Physical examination: The vet conducts a thorough physical exam, checking the horse’s vital signs, body condition, and overall appearance. All body systems should be checked in a thorough pre-purchase examination, although certain elements, such as breeding soundness, are less relevant in some cases. Systems to check include:

• cardiothoracic (heart and lungs) system: murmurs, arrhythmias, nasal discharge
• dermatologic (skin): areas of depigmentation, masses, dermatitis, surgical scars
• oral (mouth): dental abnormalities
• ophthalmic (eyes): cataracts, uveitis, corpora nigra cysts
• musculoskeletal system: conformation, gait
• nervous system: normal reflexes, muscle atrophy, coordination
• reproductive system: breeding soundness, masses, discolourations

3. Lameness evaluation: This critical component, whilst part of the general musculoskeletal assessment, usually forms a large, if not the largest, part of the examination. In this portion, the vet assesses the horse’s gait, performs joint flexion tests, and checks for a response to hoof testers to detect any signs of lameness or discomfort.
4. Diagnostic testing: Depending on the findings, the vet may recommend further diagnostics, such as X-Rays, ultrasound, or endoscopy, to investigate specific areas of concern. Routine bloodwork can check for general health indicators and screen for infectious diseases. Further tests like a drug screen or reproductive evaluation may be advised based on the horse’s intended use and initial exam results.

A note on flexion tests

Flexion tests are diagnostic tools vets use to assess a horse’s limbs for signs of pain, stiffness, or lameness. The tests involve flexing a joint or a group of joints in the horse’s leg for a short period and immediately observing his movement as he trots away. The aim is to identify any abnormalities in gait that may indicate underlying issues.

How flexion tests are performed

1. Preparation:The horse is usually trotted in hand to establish a baseline of his usual gait.
2. Flexion:The examiner holds a specific joint or group of joints in a flexed position for a set period, typically 30 to 60 seconds. Common areas for flexion tests include the fetlock, pastern, knee (carpus), hock, and stifle.
3. Observation:The horse is trotted off immediately after releasing the flexed joint. The examiner observes the horse’s gait, looking for any signs of lameness, such as limping, short-striding, or uneven weight-bearing.
4. Assessment:Each leg is tested separately, and the results are assessed based on the severity and duration of any lameness observed.

Interpretation of results

Negative test: If the horse trots off without showing any signs of discomfort or lameness, the test is considered negative, indicating no significant issues in the tested joint.

Positive test: The test is considered positive if the horse shows signs of lameness immediately after the joint is released. The degree of lameness can vary, and the results are often graded on a scale.

Considerations

• Subjectivity: The interpretation of flexion tests can be subjective, and results may vary depending on the examiner’s experience and the horse’s condition.
• False positives: Some horses may show a positive response to a flexion test even in the absence of significant pathology. Factors such as the horse’s age, fitness level, and previous injuries can influence the results.
• Diagnostic tool: Flexion tests are just one part of a comprehensive lameness examination. Positive results may warrant further investigation with diagnostic imaging (such as X-Rays or ultrasound) to determine the underlying cause, i.e. a positive flexion test is not a diagnosis in itself.

Conclusion

Flexion tests are a valuable tool in the assessment of equine lameness. They provide helpful information about the health and function of a horse’s joints and can help identify areas that may require further investigation. However, the results should be interpreted in the context of a complete lameness examination and considered alongside other clinical findings.

A note on X-Rays

The number of X-rays a veterinarian orders depends on the level of information the client wants. A complete set for most sporthorses consists of 40 to 42 views: four views of both front feet, four views of all four fetlocks, four views of both hocks, two views of each stifle, multiple lateral views of the neck and back, and sometimes a lateral view of each carpus (knee). To save money, clients may choose a limited set of images to screen certain ‘hotspots’.

However, the story the X-Rays tell is not always straightforward, and care must be taken when interpreting radiographs, as it is common to find changes that do not relate to a clinical problem. Lots of horses, for instance, have X-Ray changes that will never cause a problem, whilst others have no changes and rapidly develop issues. Ultimately, even with X-Rays, it is hard for vets to give potential owners the kind of certainty they are hoping for.

Some specific issues vets check for on X-Ray include:

• Navicular: There is a lot of variety in this foot bone, and not every change indicates an issue. On the other hand, navicular bones may look normal, but an MRI may reveal serious deep flexor tendon injury. Cysts and lucencies (less dense areas) viewed on X-Rays are clear red flags.
• Negative palmar angle: It’s a good idea to check the angle of the horse’s coffin bone relative to the pastern in the foot. A negative hoof-pastern axis makes the horse more prone to heel bruising and increased soreness in the navicular bone.
• Sidebone: Calcification of the collateral cartilage, or sidebone, can be a sign of abnormal mechanics in the foot. While horses can be sound, some experience fractures and subsequent lameness.
• Laminitis: Damage to the tissue between the hoof and coffin bone is often not disclosed, so vets should look for subtle signs such as remodelling, the thickness of the hoof wall, and evidence of rotation of the pedal bone.
• Osteoarthritis:Arthritis in high-motion joints, such as the coffin or fetlock joints, is frequently problematic from a management perspective. If a seller can provide previous X-Rays that show static change over time, this can be somewhat reassuring, but they are still no guarantee of future stability.
• Osteochondritis dissecans (OCD): Bone fragments in joints can contribute to inflammation, changes in cartilage, and osteoarthritis development. During an exam, vets will consider whether the fragments may later cause problems and whether surgery is an option. Small, smooth, and round chips are less problematic, while multi-fragmented chips often need to be removed. Bigger stifle chips in such a high-motion joint can also be a problem.
• Cysts: Bone cysts are areas of lytic bone or bony voids. Cysts that are near joints are usually major red flags.
• Dorsal spinous processes: Kissing spines vary in appearance on X-Ray. Some horses with very narrow spacing in their backs have good muscling and no soreness, while for others, it is problematic.
• Mineralisations: Small, random mineralisations may be due to previous injections or more serious causes such as coffin joint disease.
• Withers fractures: These fractures can occur when a horse flips over. Once they heal, the horses usually do fine. However, it may be a little harder to fit a saddle to them.
• Suspensories: Warmbloods can have larger suspensories (ligaments supporting the fetlock), depending on their size, but clear abnormalities may suggest disease. A thickened suspensory should be considered in context.

Choosing the right vet

It’s crucial to select a vet who is experienced in performing pre-purchase exams. To ensure an unbiased assessment, it’s advisable to choose an independent vet who does not have a prior relationship with the seller. Communication is key; you should discuss your expectations and any specific concerns with the vet before the exam.

Interpreting the results

After the exam, the vet will provide a detailed report of the findings. It’s important to discuss these results with the vet to fully understand their implications. Some issues may be manageable or irrelevant to the horse’s intended use, while others could be deal-breakers.

The role of the pre-purchase exam in the buying process

The pre-purchase exam is invaluable for making an informed decision when buying a horse. It helps identify potential health issues that could affect the horse’s performance or require costly treatment. The results can also be used to negotiate the purchase price or terms of the sale.

There are many reasons, however, such as past personal experiences or a horse’s proven performance record, why you may decide to make a purchase even with risky conditions or pass on a horse despite a clean bill of health.

Final thoughts

A pre-purchase exam is a crucial step in the horse-buying process. It provides peace of mind and helps ensure that the horse you choose is a good fit for your needs and expectations. By investing in a thorough veterinary evaluation, you can avoid unpleasant surprises and set the stage for a rewarding partnership with your new equine companion.