Continuous digital hypothermia initiated after the onset of lameness prevents lamellar failure in the oligofructose laminitis model.

This research explores the effects of digital hypothermia (cooling) on laminitis in horses, finding that it reduces severity of the condition and prevents further injury when applied after lameness is detected.

Research Objective and Methodology

• The study aimed to examine the potential therapeutic benefits of digital hypothermia, specifically when it is applied after the onset of lameness caused by an experimental acute laminitis model.
• The research team carried out a randomised, controlled (within subject), blinded, and experimental trial involving eight Standardbred horses.
• Laminitis was induced in the horses using the oligofructose model, a well-known method for triggering the disease.
• After lameness was detected in the horses, one forelimb of each animal was subjected to continuous cooling (referred to as CRYO), while the other forelimb was kept at ambient temperature (labelled as NON-RX).
• The researchers harvested dorsal lamellar sections (proximal, middle, and distal) from the horses 36 hours after the onset of lameness.
• Both laminitis pathology and morphometric analyses were performed by two blinded observers. The observers graded the laminitis pathology from 0 (normal) to 4 (severe).

Results of the Study

• The histological scores were greater in NON-RX limbs, indicating more severe disease, compared with the cooled (CRYO) limbs.
• A complete physical separation of the lamellar dermis from the epidermis (the highest score of 4) was observed in NON-RX limbs, but was not seen in any of the cooled limbs.
• The researchers could only carry out histomorphometry, which measures the microscopic structure of tissues, on the sections that remained intact.
• In the intact sections, there was a noticeable increase in total and secondary epidermal lamellar length and a decrease in secondary lamellar width in the NON-RX limbs compared with the cooled limbs. This indicates more severe changes in the lamellar structure due to the disease.

Conclusions and Implications

• The study concluded that digital hypothermia, applied after the onset of lameness, successfully reduced the severity of lamellar injury and prevented complete separation of lamellar dermis and epidermis.
• The data suggest that therapeutic digital hypothermia may be an effective treatment for acute laminitis, providing the first evidence of its kind.
• The findings could offer a promising new approach to manage laminitis in horses, often a painful and potentially life-threatening disease, through a relatively simple and non-invasive method.