Clinical Relevance of Assessing Serum Amyloid and Main Biochemical Parameters in Newborn Ragusano Donkey Foals During the First Month of Life

The assessment of serum amyloid A (SAA) has been added to routine blood work in equine practice to support clinicians in the early recognition of acute infection and inflammation [1]. This acute phase protein rapidly increases from 10 up to 1000 times following the onset of the acute phase response [2]. Despite the increasing interest in donkeys rearing for milk production or for pet therapy purposes, no information is available about SAA reference ranges in donkey species. Considering the relevant economic loss deriving from losing a donkey foal, the use of SAA for the early diagnosis of inflammatory/infectious disease could be of great importance at this age. Materiali e metodi A total of 30 foals were enrolled in the study, n.10 (6 males, 4 females) newborn donkey foals within 48h from birth (Group A) and n.20 (11 males, 9 females) donkey foals at 30 days of age. Blood samples were collected from the jugular vein into 10 mL tubes containing clot activators. Sera obtained after centrifugation for 10 minutes at 1,000 g were tested for Potassium (K), Sodium (Na), Chloride (Cl), Calcium (Ca), Phosphorus (P), Calcium/Phosphorus ratio (Ca:P) blood urea nitrogen (BUN), ?-glutamiltrasferasi (GGT), glucose (Glu), creatinine (Cre), glutamic oxaloacetic trans-aminase (GOT), serum glutamic pyruvic transaminase (GPT), lactate dehydrogenase (LDH), Alkaline phosphatase (ALP), cholesterol (Chol), triglyceride (Trig), creatine kinase (CK), total bilirubin (tBil), direct bilirubin (dBil), indirect bilirubin (iBil), total protein (TP), albumin (Alb), globulins (G) Albumin/Globulin ratio (Alb:G) by automatic clinical chemistry analyzer. Serum Amyloid A (SAA) has been detected in serum samples by a solid phase sandwich enzyme-linked immunosorbent assay (ELISA) using the multispecies Tridelta PhaseTM range SAA kit. Student’s T-tests were performed to highlight significant differences in studied blood parameters between Group A and B, values of p< 0.05 were considered statistically significant. Risultati According to our results, BUN, Cre and ALP decreased during the first month of life in Ragusano donkey foals passing from 26.62±8.31mg/dl to 18.042±5.32 for BUN (p=0.006), from 1.707±0.36 mg/dl to 1.262±0.16 mg/dl for Cre (p=0.002), and from 2,330.6±1,062.84 UI/l to 867.474±258.75 UI/l for ALP (p=0.001). Similar trend for these parameters has been observed in Amiata and Martina Franca donkey foals [3,4]; on the contrary, LDH significantly decreased (p=0.001) in Ragusano donkey foals whereas no significant modification was observed in Martina Franca breed [4]. In the same manner, serum TG increased (p=0.011) from 66.9±11.82 mg/dl in newborns to 85.189±28.57 mg/dl in older Ragusano foals, but no significant difference was found in TG concentrations in Amita or Martina Franca foals [3,4]. Among serum electrolytes, we observed a slight decrease in Na at 30d of life compared to neonatal period, and a significant increase of P as already found in Martina Franca donkey foals [4]. Differently from other authors who found no significant change in albumin serum concentrations, we observed a slight decrease in Ragusano donkey foals at 30d [3,4]. The assessment of SAA in this study revealed mean values of 37.44±19.76 ug/ml in healthy newborns donkeys and significant lower (p=0.006) SAA values 16.04±18.14 ug/ml in donkey foals at 30 days of age. Currently, the commonly accepted reference range for equids (0–20 ug/ml) has been assessed in healthy horses, with no sex-related differences, but an age-related effect has been reported with healthy neonatal foals showing mean SAA of 27.1 ug/ml within the 470 26° CONGRESSO MULTISALA SIVE Back on track BOLOGNA, 28-29 GENNAIO 2022 3th day of life [5]. A sepsis score has been developed for equine foals where SAA <30 ug/ml represented zero score, i.e. no sepsis, while SAA >150 ug/ml could be given a high score for septic foals, values between 30 and 150 ug/ml intermediate and those <30ug/ml zero score [6]. Conclusioni Despite no proper sepsis score exists at present for donkeys, this study improves the knowledge about SAA in donkeys providing useful information to clinicians that need to refer to specific reference ranges according to animal age when assessing a sick donkey foal. Bibliografia 1. Kay et al. Determining factors and interspecific modeling for serum amyloid a concentrations in working horses, donkeys, and mules. Res. Vet. Sci. 2019, 125, 256–265. 2. Nolen-Walston R. How to Interpret Serum Amyloid A Concentrations. AAEP 2015, 61, 130–137. 3. Sgorbini et al. Hematology and Clinical Chemistry in Amiata Donkey Foals from Birth to 2 Months of Age. J. Equine Vet. Sci. 2013, 33, 35– 39. 4. Veronesi et al. Blood analysis in newborn donkeys: Hematology, biochemistry, and blood gases analysis. Theriogenology 2014, 82, 294– 303. 5. Witkowska-Pilaszewicz et al. Serum amyloid A in equine health and disease. Equine Vet. J. 2019, 51, 293–298. 6. Stoneham et al. Measurement of serum amyloid A in the neonatal foal using a latex agglutination immunoturbidimetric assay: Determination of the normal range, variation with age and response to disease. Equine Vet. J. 2001, 33, 599–603.