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In veterinary medicine there is an increasing interest in the application of proteomic techniques to investigate protein patterns in healthy and diseased animals; however, data on urine proteome are still limited. The aims of this study were to identify a urine protein profile in healthy cats and to compare it with those obtained in patients affected by chronic kidney disease (CKD). Urine samples were collected by cystocentesis from 23 healthy and 18 CKD cats. Urinalysis was performed and urine protein to creatinine ratio (UPC) was calculated. Urine proteins were separated by SDS-PAGE on 4-12% gels, 20 different protein bands were cut, reduced, alkylated and digested by trypsin before ESIQ-TOF mass spectrometry analysis; protein identification was performed using MASCOT science search engine. CKD cats had significantly higher UPC (median 0.9, P < .01) and significantly lower urine specific gravity (USG, median 1.014, P < .01) than healthy cats (UPC 0.1; USG 1.070). SDS-PAGE allowed visualization of qualitative and quantitative differences in protein profiles. CKD cats had significantly less bands (P < .01), particular at molecular weight (MW) > 100 kDa (P < .01). Eleven different proteins were identified by mass spectrometry in cat urine. In CKD a2-macroglobulin (168 kDa) and uromodulin (90 kDa) disappeared, while albumin (64 kDa), retinol-binding protein (RBP, 22 kDa) and cystatin (16 kDa) were enhanced. Cauxin (carboxylesterase 5A, 61 kDa), transferrin (80 kDa), angiotensin-converting enzyme 2 (93 kDa), inter-a-trypsin inhibitor heavy chain H4 (103 kDa), albumin- (55 kDa) and cauxin- (40 kDa) fragments, haptoglobin (45 kDa) and immunoglobulin light chains (24 kDa) were also identified. In conclusion, proteomic techniques were successfully used to investigate urine proteins, revealing different patterns between healthy and CKD cats; some of these proteins could be considered as promising biomarkers of chronic renal damage in feline patients.

In veterinary medicine there is an increasing interest in the application of proteomic techniques to investigate protein patterns in healthy and diseased animals; however, data on urine proteome are still limited (1,2,3). The aims of our study were to identify a urine protein profile in healthy cats and to compare it with those obtained in patients affected by chronic kidney disease (CKD). Urine samples were collected by cystocentesis from 23 healthy and 18 CKD cats. For all samples urinalysis and urine protein to creatinine ratio (UPC) were performed. Urine proteins were further separated by SDS-PAGE and the bands were reduced, alkylated and then digested by trypsin before ESI-Q-TOF mass spectrometry analysis. Protein identification was performed using MASCOT science search engine. Healthy cats had significantly (p

In veterinary medicine there is an increasing interest in the application of proteomic techniques to investigate protein patterns in healthy and diseased animals; however, data on urine proteome are still limited. The aims of our study were to identify a urine protein profile in healthy cats and to compare it with those obtained in patients affected by chronic kidney disease (CKD). Urine samples were collected by cystocentesis from 23 healthy and 18 CKD cats. For all samples urinalysis and urine protein to creatinine ratio (UPC) were performed. Urine proteins were further separated by SDS-PAGE and the bands were reduced, alkylated and then digested by trypsin before ESI-Q-TOF mass spectrometry analysis. Protein identification was performed using MASCOT science search engine. Healthy cats had significantly (p

Background: Urinary proteome is a topic not deeply investigated in dogs. Leishmaniasis (L) and Cushing’s Syndrome (CS) are frequently associated with persistent proteinuria. Evaluation of urine proteome with sensitive methods is considered a non invasive procedure to monitor the therapy and select novel biomarkers. Objectives: Comparison of urinary electrophoretic profiles between healthy (H) and diseased dogs (L, CS) at the time of diagnosis and during the treatment monitoring. Methods: Urine samples were collected from 49 dogs (12 H, 26 L, 11 CS) and Urine Protein and Albumin to Creatinine ratios (UPC, UAC), HRE and SDS-PAGE were performed. Electrophoretic profiles were analyzed by ImageJ©; proteins were identified by ESI-Q-TOF. Results: UPC and UAC (mean±SD) were significantly higher (p

Background: Data on the urinary proteome of domestic animals are limited, as a consequence the study of urinary proteome of healthy domestic animals is the first step to discover new biomarkers of nephropathy. Objective: The study of the urine proteome from healthy dogs, cats, horses and cows. Methods: Urine samples were collected from clinically healthy dogs (15), cats (10), horses (37) and cows (10). For all samples, UP/C was calculated and SDS-PAGE with silver staining was performed. Results: All samples had UP/C lower than 0.2. After SDS-PAGE, all samples showed many bands, which were undetectable by routine methods. In dogs were found 15-19 bands, in cats 17-20, in horses 13-15 and in cows 15-18. On the basis of the apparent molecular weight (MW) reported in kDa and comparing with human urine proteome, we tried an identification of the most represented proteins: P90 (Tamm-Horsfall), P76 (transferrin), P64 (albumin) P54 (immunoglobulin heavy chain) P27 (immunoglobulin light chain) and P14 (lysozyme). All samples presented putative albumin, transferrin, IG heavy and light chains; Tamm-Horsfall was clearly evident in dogs, horses and cats. Dogs and cows presented proteins mainly at MW lower than albumin, cats presented proteins mainly at MW higher than albumin, while horses presented proteins at both high and low MW. Conclusion: SDS-PAGE/silver staining is a very sensitive method to detect low abundance proteins in urine of healthy domestic animals, allowing the identification of different species-specific electrophoretic profiles. Work is in progress to confirm the identity of the different proteins.

Magnesium (Mg) is the fourth most-prevalent cation in the body and it is found predominantly in bone but also in muscle and neuronal tissue; plasma and red blood cells contain less than 1% of the total body Mg. Disorders of Mg regulation are rarely reported in critically ill foals. The aims of this study were: 1- to evaluate total plasma Mg concentration in healthy foals during the first 72 hours of life; 2- to evaluate total plasma Mg concentration during the first 72 hours of hospitalization in sick foals affected by perinatal asphyxia syndrome, prematurity/dismaturity, or sepsis; 3- to compare total plasma Mg concentration between healthy and sick foals; 4- to evaluate the association of Mg concentration at admission with survival and primary clinical diagnosis. Mg concentration measured in healthy foals (n=20) did not show any time-dependent changes. In sick foals (n=97), Mg concentration evaluated at T0 was statistically higher than Mg concentrations measured at subsequent times. Foals affected by PAS (n=20) had a Mg concentration significantly higher (p

In human sport medicine, clinicopathological abnormalities are frequently detected in response to different training periods or competitions. Similar findings are described in equine medicine especially for plasmatic muscular enzymes (PMEs), oxidative stress markers and erythrocyte alterations, however their significance related to the performance is still unclear. The aim of this study was to compare clinicopathological data obtained from horses entered at 2 different high speed – short term real competitions. The first group (G1) included 34 Standardbred racing horses performing a trotting race for a total distance of 1660 m in about 2 minutes. The second group (G2) comprised 10 Thoroughbred horses involved in a galloping race, consisting in repetitive tracks of 154 m each in about 12 seconds. Blood samples were obtained before and after the races. CBC, biochemical and haemostatic parameters including PMEs (Creatine Kinase – CK; Lactate Dehydrogenase – LDH; Aspartate Transaminase – AST) Uric Acid (UA), Haptoglobin (Hp), Fibrinogen (Fib) and D-Dimer (DD), were evaluated. DD and Hp were assayed with immuno-turbidimetric methods. The post exercise data were corrected using an estimation of the plasma volume contraction according to the individual Albumin (Alb) concentration increment. The variation of each parameter was compared within- and between-races. The statistical analyses were carried out using non parametric tests for data within- and between-groups. A difference was considered significant at p

The evaluation of iron metabolism in course of chronic kidney disease (CKD) is justified by the still growing number of studies in humans. Similar reports in veterinary patients are rare or completely missing. The aim of this study was the evaluation of the Iron Status in canine patients affected by CKD, and the assessment of a potential correlation between iron homeostasis, progression of the CKD, and presence of an acute phase response (APR). The medical records of dogs, referred for a nephrological evaluation from January 2007 to December 2009, were analyzed. Fortysix dogs with CKD were selected and compared with healthy dogs (n 5 28). Considering a cut-off hematocrit value (HCT) of 35%, CKD dogs were afterwards divided in 2 groups defined as ‘‘anemic’’ and ‘‘non-anemic’’. Based on the International Renal Interest Society (IRIS) guidelines, CKD dogs were further divided in stage II, III and IV. Iron Status was assessed by the evaluation of Total Iron, Ferritin, Total Iron Binding Capacity (TIBC), TIBC-saturation %, and haematological parameters together with an acute phase proteins profile comprehensive of C-reactive Protein (CRP), Haptoglobin (Hp), and Albumin (Alb). CRP, Hp and Ferritin were measured using immunoturbidimetric methods. The Urinary Protein to Creatinine ratio (UPC) was also evaluated. Iron deficiency in the CKD dogs was defined by the presence of at least one of the following: hypoferremia, hypoferritinemia, increased TIBC, and decreased TIBC-saturation. Thus a prevalence of iron deficiency of 43% (20/46) was achieved. The concomitant presence of the 4 cited abnormalities was detected in the 2% of dogs (1/46). Considering hypoferritinemia as a more specific estimation of iron deficiency, the prevalence gets to 11% (5/46). These findings suggest that iron abnormalities are common in CKD patients. A concurrent APR was detected in 36/46 dogs, potentially affecting the Iron Status. Indeed, Ferritin concentrations were higher in the CKD dogs than in healthy ones, while Total Iron and TIBC-saturation% were lower. In our population, ‘‘anemic’’dogs presented lower Total Iron and negative APP concentrations compared to the ‘‘nonanemic’’ ones, withUPC not different between groups. No significant differences in the iron profile were detected between IRIS stages. Further studies in a wider population of dogs with CKD, evaluating the prognostic role of iron profile and its potential impact on treatment strategies, are warranted.

Gli enzimi superossido dismutasi (SOD) e catalasi (CAT) sono importanti in quanto svolgono, insieme ad altre molecole ad attività catalitica, attività antiossidante nelle cellule e nei tessuti di numerosi organismi. Il grande interesse intorno a queste molecole catalitiche va cercato principalmente in due fattori: 1)sono utilizzati come biomarkers per quantificare il grado di stress ossidativo cellulare; 2) sono coinvolti in malattie degenerative del sistema nervoso centrale. Il presente lavoro è volto ad individuare metodiche per l’evidenziazione, in tessuti di orata (Sparus aurata), degli enzimi Cu/Zn SOD e CAT. SOD: è stata osservata positività diffusa nel citoplasma ed in alcuni casi nel nucleo di cellule di fegato, rene, enterociti, pirenofori dei plessi enterici, miocardiociti del tessuto ventricolare e macrofagi sub-endocardici nel bulbo cardiaco, epitelio branchiale e pirenofori del sistema nervoso centrale. CAT: il segnale era citoplasmatico sottoforma di granulosità di dimensioni e quantità differenti in funzione dei diversi tessuti: granuli citoplasmatici ben apprezzabili e diffusi nel fegato e nei tubuli renali; positività granulare più fine negli enterociti, nell’epitelio branchiale, neuroni e cellule gliali. Le differenti caratteristiche nell’espressione del segnale fra i due enzimi indagati nel presente lavoro confermerebbero la specificità dei risultati. La Cu/Zn SOD è prevalentemente citoplasmatica mentre la CAT è confinata nei perossisomi e/o microperossisomi in funzione delle cellule e tessuti interessati.

Trace elements normally occur in living tissues in low concentrations, even though elements like zinc and copper are essential for growth, health and fertility. Metallothioneins (MTs) play an important role in controlling tissue concentrations of Zn, Cu and Cd and tissue functions. In this paper are reported studies on trace elements and MTs in different animal species. The liver was riche in essential and non-essential metals, due to the physiological role played in the processes of detoxification and storage. Among the investigated metals, Cd reached high concentrations in the kidney of wild birds mainly bound to MT. Preliminary studies that we performed in the mammary gland tumors of dog indicated higher expression of the MT2A isoform. Much remains to be learnt about the role of MTs in organisms and the integrated approach proposed by systems biology could help in this stimulating challenge

With the introduction of molecular biology techniques in medicine, new biochemical tools are available for determining a diagnosis. Transcriptional profiling and proteomics represent a major subject in translational clinical research. Metallothionein is a small molecular weight protein, having a strong affinity for heavy metals. However, despite to the increasing experimental data, the true function of this elusive protein remains to be identified. Due to the induction by a variety of stimuli, metallothioneins are considered valid biomarkers in environmental and medical fields. In this respect we present data related to the isolation and quantification of metallothionein in tissues of reptiles and mammals naturally exposed to heavy metals. In green turtles from the Caribbean Sea, copper-metallothionein in the liver was 10 times higher than the concentration found in the liver of loggerhead turtles from the Mediterranean Sea. As regards to mammals, the badger kidney metallothionein was rich in zinc, copper and cadmium, while in fox from the same area, only traces of the protein were found. These results are indicative of a different environmental metal exposure or a different mechanism in the control of metallothionein transcription. Moreover, in our laboratory, preliminary studies were conducted to evaluate the expression of metallothionein in mammary tumors of bitches. Western blotting patterns failed to identify the monomeric form of the protein; immunoreactive bands were present in correspondence of higher molecular weight molecules, which could be related to polymeric forms of metallothionein caused by disulphide bridges.

Metallothioneins (MTs), firstly isolated in the equine kidney, are ubiquitous low molecular weight proteins and polypeptides of extremely high metal and cysteine content which give rise to metal-thiolate clusters. Any protein or polypeptide resembling mammalian MTs can be classified as MT. MTs constitute a protein superfamily of 15 families which comprise a large number of sequences inferred from both aminoacid and polynucleotide sequences obtained from all animal phyla examined so far and also from certain fungi, plants and cyanobacteria. In mammals, the MT gene family consists of four subfamilies designated MT-1 through MT-4. The study of MTs needs the competences in different fields, which range from analytical chemistry and structural spectroscopy to molecular biology and medicine. Till now does not exist a simple quantification method whereas the sophisticated 2D NMR spectroscopy shows that notwithstanding MTs have different aminoacid sequences they have similar spatial structure with metal-thiolate clusters containing 3 or 4 bivalent metal ions. Increasing body of evidence shows that mammalian MT-1 / MT-2 isoforms are involved in zinc homeostasis, protection against heavy metal toxicity and oxidative stress. MT-3 is expressed mainly in neurons but also in glia while MT-4 is mostly present in differentiating stratified squamous epithelial cells. Due to the induction by a variety of different stimuli the MT determination is considered a valid biomarker in environmental and medical field. However the true biological role of these proteins is still enigmatic.

Copper is an essential micronutrient, but in excess it is highly toxic due to reaction with intracellular thiol groups and the initiation of oxidative damage. Recent studies in mammals have shown that cellular uptake and efflux are mediated by high affinity carriers, whilst cellular toxicity is minimised both by a series of specific chaperone proteins which carry and deliver the metal to apometalloenzymes and by sequestration of excesses by metallothionein. In aquatic organisms anthropogenic copper discharges (eg. from viniculture) are a serious problem in some areas and in this preliminary study we have investigated copper homeostasis in a copper-exposed fish, the Sea Bream, Sparus aurata. Further studies on two fish species which show an apparent defect in hepatic copper efflux have also been initiated. cDNAs for a high affinity copper uptake transporter (saCTR1), a copper chaperone (saATOX1), an efflux pump (saATP7) and the heavy metal detoxification protein metallothionein (MT) were cloned, the first three for the first time from a lower vertebrate. Quantitative assays for transcript expression were developed and used to study effects of exposure to both waterborne copper and different dietary copper levels. The deduced amino acid sequences of the four investigated protein showed very high structural conservation between fish and man. Responses to waterborne copper exposure were most marked. Expression of saCTR1mRNA was reduced by copper exposure in gill and liver, there was an initial induction of hepatic saATP7mRNA expression, and hepatic MTmRNA levels were induced, indicating regulation of intracellular copper. Moreover induction of glutathione reductase indicated that it elicited an oxidative stress response. Dietary exposure reduced CTR1 mRNA expression in intestine but at low dose levels there was an initial elevation in both CTR1 and ATP7 mRNA levels in liver. These results indicate tissue differences in response and one explanation which is being investigated is that this may be attributable to differences in copper speciation and availability. AKNOWLEDGEMENTS: Work supported by EU LSF and grant from the Ministero Politiche Agricole, VI piano

While some trace elements as Cu and Zn are essential for many biological functions, Cd is considered only for its toxicity and rises the greatest biological and environmental concern, due to the increasing contamination of soil caused by human activities. The reported research is part of a project carried out in our laboratory on ecotoxicological risks and detoxification mechanisms in terrestrial and aquatic animals environmentally exposed to heavy metals (1,2). In the present study, we analysed the concentrations of Cd, Cu and Zn in terrestrial wild animals from the Quaderna Valley, a partially unpolluted area, 15 km SW of Bologna. In addition, in two selected species, fox and badger, we isolated metallothonein (MT) in kidney and liver. Cd, Zn, and Cu concentrations were determined by atomic absorption spectrometry (AAS) in selected tissues of fox, badger, hare, pheasant, quail and snail. MT was isolated by gelfiltration chromatography from liver and kidney of fox and badger. MT was detected by AAS by measuring Zn, Cu and Cd concentrations in the eluted fractions. Due to their essentiality in biological systems, Cu and Zn were present at detectable concentrations in all samples, showing similar levels in the examined species, with the exception of high levels of Cu in snail, due to the presence of hemocyanin. Cd was found in detectable amounts only in the kidney and liver; the kidney metal concentrations varied between a minimum of 0.26 mg/kg wet wt in fox to a maximum of 3.93 mg/kg wet wt in badger. The highest kidney Cd levels found in quail and badger are due to the earthworm-based diet, as previously reported for woodcock (1). This is confirmed by the presence of Cd-MT in the gelfiltration pattern. Overall, the reported data are indicative of a low metal environmental contamination. AKNOWLEDGEMENTS: Work supported by RFO 2004

The aquatic environment is the largest sink for the highly toxic organotin compounds, particularly as one of the main sources is the direct release of organotins from marine antifouling paints. The aim of this study was to investigate the genotoxic effect of some organotins in Scapharca inaequivalvis erythrocytes.

Binding of transition metal ions to the reaction center (RC) protein of the photosynthetic bacterium Rhodobacter sphaeroides slows the light-induced electron and proton transfer to the secondary quinone, QB (Utschig et al., 1998, Biochemistry 37, 8278; Paddock et al., 1999, Proc. Natl. Acad. USA 96, 6183). On the basis of X-ray diffraction (XRD) at 2.5 A ° resolution a site has been identified at the protein surface which binds Cd(II) or Zn(II). Both metal ions binds to the same cluster formed by AspH124, HisH126 and HisH128. A water molecule was also proposed to interact with the Zn (Axelrod et al., 2000, Proc. Natl. Acad. Sci. USA 97, 1542). Recent data suggest that inhibition of proton transfer by Cd(II) is predominantly a consequence of competing with protons for binding to HisH126 and HisH128, thus hampering the function of these residues as proton donor/acceptors along the proton pathway to the QB site (Paddock et al., Biochemistry 42,9626, 2003). Determination of the local structure of the bound metal ions is expected to contribute significantly to elucidate the details of the inhibition mechanism. For this reason we performed Zn K-edge X-ray absorption measurements on Zn-doped RCs embedded into polyvinyl alcohol films at both room and liquid nitrogen temperature. Data analysis has been performed using ab-initio simulations and multiparameter fitting; structural contributions up to the fourth coordination shell and multiple scattering paths (involving three atoms) of significant amplitude have been included. Results for complexes characterized by a Zn to RC stoichiometry close to 1 indicate that Zn binds two O and two N atoms in the first coordination shell. The two N atoms come from His, and only one of the two O atoms comes from an amino acid (Asp or Glu); the second O atom belongs to a water molecule. Complexes characterized by approximately two Zn ions per RC show a second structurally distinct binding site, involving three N and one O atom, all coming from nonaromatic residues. The results obtained for the higher affinity site nicely fit the coordination proposed on the basis of XRD data. The second binding site, revealed by our investigation on noncrystalline samples, is most probably located in a more disordered domain of the RC protein and might have a hitherto not appreciated role in charge transfer inhibition.

The cytochrome P450 catalyses the oxidation of a wide variety of compounds by inserting a single atom of molecular oxygen into the substrate. Concerning to molluscs, the MFO system (or its component) has been identified in different tissues of several bivalve, and the highest activity was found in the digestive gland. The aim of this study is to prove, by immunochemical analysis, the presence and the induction in the bivalve mollusc Scapharca inaequivalvis of two different isoforms of cytochrome P450 (CYP): 1) CYP 1A, that responds specifically to various PAHs and PCBs and 2) CYP 2E which is induced by alcohols, benzene and alkylnitrosamines. Since cytochrome P450 is a key enzyme in the detoxification systems, the induction of specific forms of P450 can be used as a particular biomarker of environmental pollution

Bivalve molluscs, as Scapharca inaequivalvis, are filter-feeding organisms capable of bioconcentrating environmental chemical pollutants; consequently they are commonly used as bioindicators in the assessment of environmental quality. Of particular interest in this regard are the levels and the activities of enzymes involved in the xenobiotics detoxification such as MFO system, a multicomponent enzyme containing several forms of cytochrome P450, and the oxidative stress enzymes indirectly involved, such as the superoxide dismutase (SOD). Several studies carried out in fish and in marine invertebrate have demonstrated an inhibitory effect of TBT on different P450 isoforms. The aim of this work was to evaluate the effect of TBT on the content of P450 and on the activity and expression of MnSOD and CuZnSOD in a bivalve mollusc used as sentinel organism in the environmental pollution monitoring.

Two groups of young gilthead sea bream were fed two different diets: a control diet containing Zn at 120 mg/kg feed and a supplemented diet containing Zn at 240 mg/kg feed. White portions of lateral muscle were analyzed for Zn and Cu concentrations, myofibrillar composition and pyruvate kinase (PK) activity in order to determine the influence of Zn on these biochemical parameters during the growing period and a subsequent starvation phase. Levels of Zn in liver and muscle were ten times higher than those of Cu. No significant variations in metal concentrations were observed between the two diets. Myofibrillar proteins extracted from the white portion of lateral muscle were mostly constituted by myosin heavy (HC) and light (LC) chains that, as for other fish, had the following order of electrophoretic mobility: LC1F

Gold is a nonessential element with a variety of applications in medicine. A few gold(I) compounds are used in the clinics for treatment of rheumatoid arthritis and of discoid lupus. Some novel gold(III) compounds are under evaluation as anticancer agents. It is known that gold compounds generally produce toxic effects on the kidneys and characteristic lesions in the brain. However, information concerning the neurotoxicity of gold derivatives in humans as well as in experimental toxicology is rather scarce. For this reason we tried to shed some further light on this aspect of gold neurotoxicity by chronic treatment of mice with sodium tetrachloroaurate(III) in order to observe possible biophysical and morphological alterations that may occur in the brain. Chronic gold treatment resulted in a markedly decreased expression of metallothioneins and of glial fibrillary acidic protein in astrocytes of different brain areas. To examine its effects on cell membranes, interactions of sodium tetrachloroaurate(III) with molecular models were also evaluated. The models consisted in bilayers built-up of classes of phospholipids located in the outer and inner monolayers of biological membranes. Structural perturbation of cell membrane models was observed only at concentrations 10(5) times higher than those detected in the brains of animals after three months' treatment. These results show that toxic effects on animal brain upon treatment with sodium tetrachloroaurate develop with difficulty and may be observed only at high doses.

Abnormalities in total Mg (tMg) concentration in plasma and/or serum are common in critically ill humans, and the association with increased mortality has been documented in several clinical studies in adults and newborns with hypoxic-ischemic encephalopathy. Abnormalities in tMg were studied in hospitalized dogs, cats, and adult horses. Newborn foals were scarcely studied with regard to Mg concentration. The aims of the present study were: (1) to compare two analytical methods for the determination of tMg in plasma: the automated colorimetric method and the atomic absorption spectrometry; (2) to measure plasma tMg in healthy foals during the first 72 hours after birth and in sick foals during the first 72 hours of hospitalization; (3) to compare total plasma Mg concentration among healthy foals, foals affected by perinatal asphyxia syndrome (PAS), prematurity and/or dismaturity, and sepsis; (4) to evaluate tMg plasma concentration in surviving and non-surviving foals. One hundred seventeen foals were included in the study: 20 healthy and 97 sick foals. The automated method used in clinical practice probably overestimates plasma tMg. Due to its higher sensitivity and specificity, the atomic absorption spectrometry should be considered the method of choice from an analytical point of view, but requires an instrumentation not easily available in any laboratory and specific technical skills and competencies. Plasma tMg in healthy foals were included in the range 0.52 to 1.01 mmol/L and did not show any time-dependent change during the first 72 hours of life. In sick foals, tMg evaluated at T0 was statistically higher than tMg measured at subsequent times. Foals affected by PAS had a tMg at T0 significantly higher (P < 0.01) than healthy, septic, and premature and/or dysmature foals. The. t test found significantly higher (P < 0.01) plasma tMg measured at T0 in non-surviving than in surviving foals. Plasma tMg could be a useful parameter for the diagnosis of PAS and the formulation of the prognosis in critically ill foals.