Evaluation of Serum Lipids, Biochemical Parameters, Selected Antioxidant Elements and Oxidative Stress Profiles in Late Pregnant Jennies with Hyperlipemia

Donkeys are particularly at risk of hyperlipemia. Hyperlipemia is a metabolic disease caused by the mobilization of fatty acids from adipose tissue, which often impacts pregnant and lactating jennies (female donkeys) during periods of negative energy balance. This study aimed to evaluate the levels of lipids, biochemical parameters, selected antioxidant elements and oxidative stress parameters in late pregnant jennies affected by hyperlipemia. Compared with the healthy jennies, the hyperlipemic animals exhibited significantly elevated levels of triglycerides (TGs), total cholesterol (T-CHO) and low-density lipoprotein cholesterol (p < 0.05), coupled with reduced levels of high-density lipoprotein cholesterol and albumin (ALB) (p < 0.05). The serum levels of biochemical parameters related to liver function, such as aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase (AKP) and cholinesterase (CHE), showed a significant increase in the hyperlipemia group compared to the healthy group (p < 0.05). The serum level of selenium was significantly lower (p < 0.05) and positively correlated with TGs (r = 0.85) and ALB (r = 0.73) in the hyperlipemia group. The hyperlipemic jennies showed diminished serum levels of antioxidant capacity and increased levels of malondialdehyde (MDA). The area under the curve values for T-CHO, ALB, AKP, CHE, total superoxide dismutase, glutathione and MDA were relatively high. Thus, our findings reflect metabolic disorders, liver dysfunction and oxidative stress in late pregnant hyperlipemic jennies, providing a basis for the improvement of clinical diagnostic methods and early prevention and control of hyperlipemia in jennies.

Nutritional management of hyperlipaemia in a jenny: a brief report

An adult jenny (5-years-old, non-pregnant) was presented to the Veterinary Teaching Hospital (VTH) of the University of Sassari, with a recent history of appetite loss, extreme underweight condition and reluctance to move. On physical inspection, emaciation [body condition score, BCS: 3/9], muscular waste [muscular condition score, MCS: 1/5], loose/running faeces [faecal score, FS: 2/8], and a general state of mild dehydration were found. Blood analyses outlined a general undernourishment condition [circulating albumins, ALB: 17.6 g/L (21.6-31.6 g/L)] with underlying systemic inflammatory profile and moderate increase in circulating enzymes to explore liver function [aspartate amino-transferase, AST: 657 u/L (279-430 u/L); alanine amino-transferase ALT: 60 u/L (5-14 u/L); gamma-glutamyl-transferase, γ-GT: 87 IU/L (14-69 IU/L); total bilirubin close to the upper limit, TB: 0.20 mg/dL(0.07-0.21 mg/dL)]and hyperlipaemia [TG: 8.70 mmol/L (0.60-2.87 mmol/L)], following fat depots mobilisation, with total cholesterol closed to the lower limit of the physiological range. Hyper-phosphataemia was linked to haemolytic anaemia [P:1.81 mmol/L (0.77-1.39 mmol/L) and red blood cells, RBC: 4.14 1012/L (4.40-7.10 1012)] aligned with the TB to the upper limit. On ultrasound abdominal imaging, enlarged and hyper-echogenic liver was observed. Based on the clinical evaluation, a condition of hepatic lipidosis was diagnosed, requiring dedicated nutritional treatment to solve the extreme emaciation along with the metabolic disorder in support of medical therapy. A two-step feeding protocol was planned to support treatments aiming at immediate re-hydration (Ringer lactate solution 2 ml/kg/8 h). The nutritional objectives were meant at first to restart the voluntary feed intake. Gradual increasing energy provision through a palatable hay-based diet was planned to cover one fourth of daily metabolizable energy requirement calculated on the expected metabolic weight, adjusted according to the daily intake of feed and clinical condition. At the conclusion of this first 7-day phase, circulating blood parameters were closer to the reference values and the BCS moved from 3 to 4 out of 9. Bowel motility was restored, and faecal score improved (4/8). In the second phase, allowance to pasture and a combination diet with compound mixed feed were designed. Within four weeks of starting the nutritional plan, blood parameters were re-established to reference values. The gradual feed provision calculated in this two-phase approach proved successful in support of the overall clinical improvement observed after four weeks of treatment, in a severely undernourished jenny with compromised liver functions.

Metabolic and Endocrine Insights in Donkeys

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.

Energy hormone response to fasting-induced dyslipidemia in obese and non-obese donkeys

Metabolic and endocrine disorders, such as dyslipidemia, are common in donkeys. Negative energy balance due to fasting, stressful conditions, or disease is a major trigger for fat mobilization often leading to dyslipidemia. The hormonal response to fasting has not been well characterized in donkeys. Therefore, this work aimed to study variations in insulin, glucagon, leptin, total adiponectin, ghrelin, and insulin-like growth factor-1 concentrations, insulin-to-glucagon (IGR) and glucagon-to-insulin (GIR) molar ratios, and lipid and carbohydrate parameters during a 66 h fasting period in 8 adult donkeys, and to determine differences depending on body condition. Obese donkeys developed earlier lipid mobilization (increased plasma total triglyceride and total cholesterol concentrations) compared to non-obese donkeys. Plasma glucose and leptin concentrations decreased in obese animals. After 60 h fasting, obese donkeys showed a significant increase in glucagon and decrease in leptin. GIR significantly increased, while insulin and IGR decreased in both groups. These findings support faster lipid mobilization in response to negative energy status in obese donkeys during fasting, which could be linked to greater glucagonemia and could explain the predisposition of these animals to dyslipidemia.

Metabolic and Endocrine Disorders in Donkeys

The donkey evolved under harsh and arid environmental conditions, developing unique energy-efficiency traits, with an efficiency to rapidly mobilize fat in situations of increased energy demands or when food is scarce. This evolution has led to an inherent predisposition of donkeys to obesity, dyslipidemias, insulin dysregulation/metabolic syndrome, pituitary pars intermedia dysfunction, and endocrinopathic laminitis. Marked differences have been described in hormone dynamics and testing protocols for the diagnosis of these endocrine and metabolic diseases in donkeys compared with horses, underlining the necessity of a species-specific approach in order to avoid misdiagnosis, unnecessary or inadequate treatments, and additional costs.