Metabolic and Endocrine Insights in Donkeys

Simple Summary Hyperlipemia, defined as abnormally high blood triglyceride concentrations, is the most common metabolic disease in donkeys. In contrast, metabolic syndrome, insulin dysregulation (ID) and pituitary pars intermedia dysfunction (PPID) are the most common endocrine disorders in this species. Although diagnostic approaches for these conditions are similar to horses, donkey-specific protocols must be used. Likewise, common drugs used to treat metabolic and endocrine disorders in horses are also used in donkeys, but there is minimal pharmacologic information (regimen dose, etc.) for most of them, except for pergolide.Abstract Donkey medicine is gaining attention due to their increased use as companion animals, in shows, asinotherapy, etc. The increasing demand and unique aspects call for specialized care, requiring new information (physiology, infectious disorders, pharmacology, etc.). Since obesity is common in this species, hyperlipemia, metabolic syndrome and insulin dysregulation (ID) are common disorders in donkeys, in some cases with high mortality, either directly (multiorgan dysfunction) or indirectly due to poor quality of life (chronic laminitis). Donkeys have long-life expectancy and are often afflicted with pituitary pars intermedia dysfunction (PPID), a neurodegenerative and endocrine disease. Hyperlipemia is diagnosed based on high plasma triglyceride concentration in association with clinical findings and laboratory abnormalities from affected tissues (liver, kidney and pancreas). The measurement of resting serum insulin and plasma ACTH concentrations is the first step in ID and PPID diagnosis. In donkeys with clinical signs of ID (obesity or recurrent laminitis) or PPID (hypertrichosis, regional adiposity, laminitis and weight loss), where these hormones are in the normal or non-diagnostic range (donkey-specific cut-off values and reference ranges need to be established), dynamic tests are recommended (oral sugar test or thyrotropin-releasing hormone, respectively). Equine treatment protocols apply to donkeys, although pharmacological studies for most drugs, except pergolide, are lacking.