Particle Size Distribution of Plasma Lipoproteins in Donkeys from Death Valley Compared to a Sampling of Horses.
Authors: Goodrich Erin L, Behling-Kelly Erica
Journal: Animals : an open access journal from MDPI
Summary
# Editorial Summary Whilst routine blood work for equids typically measures only total cholesterol and triglycerides, these crude markers obscure the complex interplay between different lipoprotein classes and their metabolic roles—particularly relevant given donkeys' high susceptibility to hepatic lipidosis compared to horses. Goodrich and Behling-Kelly employed high-resolution polyacrylamide gel electrophoresis (Lipoprint®) to characterise and fractionate lipoproteins by particle size in a substantial donkey population, using horses as a comparative reference. Donkeys emerged as an HDL-predominant species, with HDL comprising 78.45% of circulating lipoproteins (range 55–92.2%), whilst VLDL accounted for 21.6% and LDL was minimal; horses, conversely, showed significantly higher VLDL proportions at 31.7% (p = 0.00008). These findings challenge the assumed causal link between elevated VLDL and hepatic lipidosis in donkeys, since the disease is substantially more prevalent in donkeys despite their lower VLDL levels, suggesting that current serum triglyceride concentrations may be an inadequate proxy for hepatic lipid exportation in this species. For practitioners managing metabolic disease in donkeys and horses, this work underscores the need for species-specific lipoprotein profiling rather than reliance on total triglyceride values alone; distinguishing VLDL from LDL through methods like Lipoprint® could improve early detection of hepatic pathology in at-risk donkeys.
Read the full abstract on PubMed
Practical Takeaways
- •Current diagnostic protocols using serum triglycerides as a hepatic lipidosis marker in donkeys may be inadequate; lipoprotein particle size profiling could improve disease detection
- •Donkeys and horses have fundamentally different lipoprotein profiles, indicating that equine-specific metabolic assessment tools are needed rather than adapted human or single-species assays
- •The high susceptibility of donkeys to hepatic lipidosis despite lower VLDL suggests other metabolic pathways or lipoprotein compositional factors—beyond simple triglyceride levels—drive disease pathogenesis
Key Findings
- •Donkeys are HDL-rich species with average HDL accounting for 78.45% of total lipoproteins compared to horses
- •Donkeys have lower VLDL proportions (21.6%) compared to horses (31.7%, p=0.00008), despite higher incidence of hepatic lipidosis
- •Lipoprint® gel electrophoresis successfully separated lipoprotein classes and sub-fractionated LDL and HDL by particle size in both species
- •The relationship between VLDL concentration, triglycerides, and hepatic lipidosis development in donkeys remains unclear and warrants further investigation