Quantitative and qualitative evaluation of dermal elastin of draught horses with chronic progressive lymphoedema.

This research investigates the link between altered elastin metabolism and chronic progressive lymphoedema (CPL), a disease that affects certain draught horse breeds, focusing on the skin of the lower limbs. The study concludes that CPL is a generalized disease, and impaired efficiency of the elastic network supporting the lymphatics in the skin can result in the disease’s development.

Study Background and Rationale

• The study was designed to explore the relationship between Chronic Progressive Lymphoedema (CPL), a disease prevalent in specific draught horse breeds, and altered elastin metabolism.
• Previous investigations suggested that the skin lesions characteristic of CPL, often seen in the distal limbs (lower limbs), were associated with modified elastin concentration and quality.

Methods

• The research incorporated horses of both susceptible and non-susceptible breeds, including a subset of susceptible horses that did not display symptoms of CPL.
• Skin samples were collected from two distinct areas – the distal limb, where CPL lesions are typically seen, and the neck, a region considered non-affected by CPL.
• These samples were then analyzed to evaluate the characteristics of the lesions and the morphological and quantitative properties of the dermal elastic fibers.

Findings

• Across all horses, researchers found that the highest concentrations of elastin were found in the superficial dermis(top layer of skin), with declining concentrations in the mid-dermis and deep dermis layers.
• Contrasting CPL-affected horses with non-susceptible breeds, it was found that the former had increased elastin levels in both the distal limb and neck.
• Interestingly, non-affected horses from the susceptible breed had lower levels of dermal elastin.

Conclusions and Significance

• These findings correlate with a previous hypothesis that CPL is a generalized disease in horses, rather than one restricted to certain body parts.
• Further, the research suggests that a lower efficiency of the elastic network in supporting dermal lymphatics could potentially explain the development of CPL.