07/18/2026
By the time a horse rotates... we've already missed part of the disease.
For decades, laminitis has often been recognized radiographically only after rotation or sinking of P3 became apparent. The problem is that lamellar structural failure (LSF) begins long before those changes become obvious. The inflammatory process starts within the lamellae, resulting in edema, vascular compromise, and progressive weakening of the suspensory apparatus of the distal phalanx. By the time displacement is visible on radiographs, the disease has often been active for days or even weeks.
One of the most exciting developments in recent years is the work by Skelton et al. (2025) demonstrating that the lamellar lucent zone (LLZ) can be measured on modern digital radiographs and is significantly increased during acute and subacute laminitis, often before traditional radiographic signs of rotation or sinking develop. Their work validates what many of us have observed clinically for years—that subtle radiographic changes within the lamellar zone can provide an early warning that lamellar structural failure is underway.
Throughout my career, performing hundreds of serial venograms has completely changed the way I evaluate laminitis. Venography has taught me that the lamellar lucent zone and the lamellar circumflex junction can often be interpreted remarkably well on high-quality digital radiographs. While venography remains the gold standard for evaluating vascular integrity, careful assessment of these radiographic landmarks can identify horses that are actively undergoing lamellar injury before catastrophic displacement occurs.
The image above illustrates one of those cases.
The turquoise lines represent the lamellar (dermal) zone, while the yellow line represents the horn (epidermal) zone of the hoof wall. The red dotted line marks the dermoepidermal junction, the interface between the hoof wall and the lamellar tissues.
In a healthy foot, the horn-to-lamellar ratio should be at least 50:50, with most normal horses actually having a thicker horn zone than lamellar zone. As edema and inflammation develop within the lamellae, the lamellar zone widens, the normal ratio is lost, and the dermoepidermal junction begins to shift. These are often some of the earliest radiographic indicators that lamellar structural failure has begun—even though the distal phalanx has not yet rotated.
This is exactly why I believe we need to stop waiting for rotation before diagnosing laminitis.
Instead, we should be asking:
Is the lamellar zone becoming thicker?
Has the horn-to-lamellar ratio changed?
Is the lamellar circumflex junction becoming abnormal?
Are these changes progressing on serial radiographs?
What do serial venograms tell us about the vascular health of the foot?
These questions allow us to identify the disease while the lamellae are still salvageable.
When these early changes are recognized, treatment should immediately focus on reducing mechanical stress on the compromised lamellae while simultaneously addressing the underlying medical cause. Appropriate trimming, leverage reduction, therapeutic shoeing, metabolic evaluation, anti-inflammatory therapy when indicated, and continued imaging all become critical components of treatment.
Mechanical therapy should not simply react to rotation—it should be used to prevent progression of lamellar structural failure.
I firmly believe that the future of laminitis management lies in early recognition rather than late intervention. Modern digital radiography, combined with serial venography and thoughtful mechanical therapy, gives us an opportunity to identify lamellar failure earlier than ever before and intervene before irreversible damage occurs.
See it early. Treat it early. Save the lamellae.
Reference
Skelton G, Acutt E, Stefanovski D, van Eps A. Evaluation of digital radiographic measurements for the diagnosis of acute laminitis. Equine Veterinary Journal. 2025;57(4):931-942. DOI:10.1111/evj.14436.
