Pre-analytical stability of selected biochemical analytes in serum of horses and oxen stored at -20°C.

BACKGROUND: Delays between blood collection and analysis are inevitable, and samples are always stored in the refrigerator. The current study aimed to evaluate the stability of serum total cholesterol (TC), triglycerides (TG), total protein (TP), albumin and urea (URA) in horses and oxen after storage at -20°C. METHODS: Sera from apparently healthy 20 male horses and 20 oxen were obtained and aliquots of serum were divided into 3 portions. The first tube was used for baseline (T0) measurement of analyte values, whereas the other two tubes, T1 and T2, were stored at -20°C for 1 and 2 months, respectively, and analyte measurement was done. RESULTS: Results showed that the stability of TP (g/dL), URA (mg/dL) and TC (mg/dL) in oxen was statistically significant (p < 0.05). In horses, the stability of URA (mg/dL), TP (g/dL) and TG (mg/dL) were also statistically significant (p < 0.05). Additionally, URA and TC in oxen exceed TEa following measurement at T2 and TG in horses following measurement at T1 and T2. CONCLUSION: Laboratories should consider the storage temperature and time for specific analytes among animals. Therefore, stability studies at various storage temperatures and times are recommended to fully validate the stability of the analytes.

Non-surgical external jugular vein catheterization using an ear vein access in piglets.

The objective of this study was to investigate the feasibility of external jugular vein catheterization through an ear vein in piglets. Forty-six sevoflurane-midazolam anaesthetized piglets were included. External jugular vein catheterization was conducted through the ear vein using the Seldinger technique. Part 1 (n = 27): optimal puncture site was based on the deltoid tuberosity as a landmark to reach the external jugular vein. The final position of the catheter was verified in 25 piglets using computer tomography. Catheterization time was recorded and patency of the catheter assessed by repeated blood sampling for up to 4 h. Part 2 (n = 19): ear vein catheterization was without taking into account any landmarks. Functionality for blood sampling was evaluated as described in part 1. Catheter advancement was possible in 25/27 and 18/19 piglets in parts 1 and 2, respectively. Median (range) time required for successful catheterization was 1.95 (1-10) min (n = 38). The deltoid tuberosity was a good landmark to reach the external jugular vein. But blood sampling was also possible through catheters ending slightly cranial to the external jugular vein. Despite successful catheter advancement, blood sampling was not possible from one catheter in each part of the study (total: two piglets). One of these catheters presented luminal damage, while the other one presented as normal after being removed from the animal. Summarizing, central vein catheterization through the ear vein was feasible in 93.5% and repeated blood sampling was possible in 89.1% of the piglets (n = 46).

A Comparison of Blood Collection Techniques in Mice and their Effects on Welfare.

Multiple methods are used to collect blood from mice; these methods have different effects on animal welfare. This study compared blood collection from facial, chin, and saphenous locations with regard to various parameters, including the time needed to collect blood, the number of attempts needed, success at completing the blood collection, volume of blood loss, weight changes in the mouse, presence of external lesions after blood collection and gross lesions at necropsy, physical signs during blood collection (vocalization, urination, and defecation), fecal corticosterone after blood collection, and blood chemistry values. While no one technique was clearly better for animal welfare, each technique had benefits and drawbacks.

Comparison of the effects of open-tube and evacuated tube-assisted sampling methods on thromboelastography variables for blood samples from healthy dogs.

OBJECTIVE: To compare the effects of open-tube blood sampling with previously investigated blood sampling methods via evacuated tube on thromboelastography variables for blood samples from dogs. ANIMALS: 10 healthy Beagles from the research colony owned by the Clinic of Small Animal Internal Medicine, University Veterinary of Medicine, Vienna, were used. PROCEDURES: In this prospective study, blood was sampled from each dog serially into citrate solution-containing tubes via 20-gauge needle. One evacuated tube was filled from a jugular vein via the evacuated tube port, and the second tube was opened and filled by catching blood flowing through the needle from a lateral saphenous vein. Venipuncture quality was scored with a previously described method. Thromboelastography was performed for each sample. RESULTS: Inferential statistics used with the Wilcoxon signed rank test showed significant differences in reaction time (R) of 3.43 ± 0.84 minutes versus 4.53 ± 0.62 minutes (mean ± SD) between evacuated tube assisted and open-tube sampling, respectively. No other significant differences were identified. CLINICAL RELEVANCE: The sampling methods compared have a small but significant effect on R in thromboelastographic analysis for blood samples from healthy dogs. Shear stress by vacuum sampling seems to accelerate coagulation in jugular blood samples harvested by evacuated tube, resulting in a shortened R. Results suggested that the open-tube method avoids shear stress induced activation of coagulation and is an appropriate sampling method for thromboelastography when used within a standardized protocol.

Effects of handling and storage on potassium concentration in plasma and serum samples obtained from cats.

OBJECTIVE: To compare potassium concentrations in feline plasma and serum samples analyzed promptly after collection or after 20 to 28 hours of refrigerated storage. ANIMALS: 41 cats. PROCEDURES: A venous blood sample was obtained from each cat. Aliquots were placed in 2 tubes without anticoagulant (blood was allowed to clot to derive serum) and 2 tubes with heparin (to derive plasma). One serum and 1 plasma sample were kept at room temperature and analyzed within 60 minutes after collection (baseline); the other serum and plasma samples were analyzed after 20 to 28 hours of refrigerated storage. At both time points, serum and plasma potassium concentrations were measured. RESULTS: Median baseline serum potassium concentration (4.3 mmol/L) was significantly higher than median baseline plasma potassium concentration (4.1 mmol/L). The median difference between those values was 0.4 mmol/L (95% CI, 0.2 to 0.5 mmol/L). Compared with their respective baseline measurements, the median serum plasma concentration (4.8 mmol/L) and median plasma potassium concentration (4.6 mmol/L) were higher after 20 to 28 hours of refrigeration. CLINICAL RELEVANCE: Results indicated that with regard to potassium concentration in feline blood samples, clotting or refrigerated storage for 20 to 28 hours results in a significant artifactual increase. Detection of an unexpectedly high potassium concentration in a cat may represent pseudohyperkalemia, especially if the blood sample was placed in a no-additive tube, was stored for 20 to 28 hours prior to analysis, or both.

Pre-analytical factors affect the accurate measurement of testosterone concentrations in plasma and serum of goats.

Several pre-analytical factors may influence the accurate measurements of testosterone (T) and therefore, these factors must be a significant concern. This study aimed to examine the effects of 1) time of sample collection, 2) delay to centrifugation, 3) sample matrix types, and 4) device and duration of sample storage on the T concentrations. Blood samples were collected from 34 bucks of Kacang goats. For testing the effect of collection time, 12 pairs of morning and afternoon samples were collected. For testing the effect of delayed centrifugation, 24 samples were subjected to treatments: (i) centrifuged ⟨1 hour after collection (control group), (ii) centrifuged 6, 12, and 24 hours after collection (test groups). For testing the different sample matrix types, 10 samples were processed as serum and plasma. For testing the effect of sample storage device and duration, 60 samples were subjected to treatments: i) frozen at -20OC (control group), ii) stored in a cooler box, a styrofoam box, and a thermos-flask for two, four, and six days (test groups). T concentrations were measured using a validated testosterone ELISA kit. Concentrations of plasma testosterone (pT) from morning samples were significantly higher compared to afternoon samples (p⟨0.05). Delayed centrifugation for up to 24 h decreased significantly on pT concentrations (p⟨0.05). The concentrations of T from serum and plasma did not differ and showed a strong correlation (r=0.981). Storage device and duration affected the T concentrations compared to frozen samples (p⟨0.05) which T concentrations were stable for up to 4 days in a styrofoam box and a thermos-flask and up to 6 days in a cooler box. In conclusion, the measurement accuracy and stability of T concentrations in goats are affected by collection time, delay to centrifugation, and device and duration of storage.

A novel canine nuclear magnetic resonance spectroscopy-based metabolomics platform: Validation and sample handling.

BACKGROUND: Metabolomics has been proven to be an invaluable research tool by providing comprehensive insight into systemic metabolism. However, the lack of scalable and quantitative methods with known reference intervals (RIs) and documented reproducibility has prevented the use of metabolomics in the clinical setting. OBJECTIVE: The objective of this study was to validate the developed quantitative nuclear magnetic resonance (NMR) spectroscopy-based metabolomics platform for canine serum and plasma samples and determine optimal sample handling conditions for its use. METHODS: Altogether, 8247 canine samples were analyzed using a Bruker's 500 MHz NMR spectrometer. Using statistical approaches derived from international guidelines, we studied method precision, measurand stability in various long- and short-term storage conditions, as well as the effect of prolonged contact with red blood cells (RBCs), and differences among blood collection tubes. We also screened interferences with lipemia, hemolysis, and bilirubinemia. The results were compared against routine clinical chemistry methods, and RIs were defined for all measurands. RESULTS: We determined RIs for 123 measurands, most of which were previously unpublished. The reproducibility of the results of the NMR platform appeared generally outstanding, and the integrity of the results can be ensured by following standard blood drawing and processing guidelines. CONCLUSIONS: Owing to the advantages of quantitative results, high reproducibility, and scalability, this canine metabolomics platform holds great potential for numerous clinical and research applications to improve canine health and well-being.

Quantification of serum fibroblast growth factor-19 concentration in healthy dogs before and after feeding.

OBJECTIVE: To measure serum fibroblast growth factor-19 (FGF-19) concentration and gallbladder volume in healthy dogs before and after feeding to determine whether serum FGF-19 concentration increases following gallbladder contraction and to assess FGF-19 stability in blood samples kept under different storage conditions after collection in tubes containing no anticoagulant or in serum separator tubes. ANIMALS: 10 healthy dogs of various ages and breeds (30 blood samples and 30 gallbladder volume measurements). PROCEDURES: Serum FGF-19 concentration was measured with a commercially available ELISA. Gallbladder volume was determined ultrasonographically. Blood samples and gallbladder measurements were obtained from the dogs after food had been withheld for 12 hours (baseline) and at 1 and 3 hours after feeding. The stability of serum FGF-19 was assessed in samples collected in tubes containing no anticoagulant or in serum separator tubes and stored at -80°C for variable intervals or 4°C for 1 or 5 days. RESULTS: Serum FGF-19 concentration was significantly increased from baseline at 1 and 3 hours after feeding. There was a significant decrease in gallbladder volume 1 hour after feeding, compared with baseline findings. Regardless of collection tube used, concentrations of FGF-19 in serum obtained from blood samples that were collected and immediately stored at -80°C differed significantly from concentrations in serum obtained from blood samples that had been collected and stored at 4°C for 5 days. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that postprandial gallbladder contraction results in increases of serum FGF-19 concentration in healthy dogs. Assessment of circulating FGF-19 concentration could be used to detect disruptions in the enterohepatic-biliary axis in dogs.

COMPARING THE EFFECTS OF LITHIUM HEPARIN AND DIPOTASSIUM ETHYLENEDIAMINETETRAACETIC ACID ON HEMATOLOGIC VALUES IN EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA).

Anticoagulants are employed to prevent clotting and preserve cellular morphology for clinical pathology tests. Lithium heparin (LH) is the most frequently used anticoagulant in chelonians; however, dipotassium ethylenediaminetetraacetic acid (EDTA) may be superior in some species. Although eastern box turtles' (Terrapene carolina carolina) hematologic parameters are well studied, the effects of different anticoagulants on hematology in this species are unknown. This study evaluated the effects of LH and EDTA on hematologic values in free-living eastern box turtles (N = 59). Blood samples were collected from eastern box turtles in Illinois and immediately divided between LH and EDTA microtainers, and complete blood counts were performed on each sample. Grossly, plasma from EDTA blood samples was frequently and significantly hemolyzed. Blood mixed with LH had higher packed cell volume (PCV) (P = 0.04), white blood cell count (WBC) determined by Leukopet (P < 0.0001), WBC determined by blood film estimate (P < 0.0001), absolute heterophils (P = 0.007), absolute lymphocytes (P < 0.0001), and lower total solids (P < 0.0001) and absolute monocytes (P = 0.0001) than blood mixed with EDTA. All relative leukocyte counts were significantly different between the anticoagulants (P < 0.0001). EDTA apparently lysed turtle erythrocytes in this study, making it difficult to accurately count white blood cells and artificially lowering PCV. These findings demonstrate that EDTA should not be used in eastern box turtles.

Blood parameters of crioulo breed horse / Parâmetros sanguíneos de potros da raça Crioula

Plasma levels of hematocrit, total plasma protein, fibrinogen, creatine phosphokinase, aspartate transferase, and lactate were analyzed in blood samples of 85 Crioula breed foals, from birth to two years of age. The animals were divided into age groups: G1 (up to 15 days of age; n=70), G2 (from 16 days to one month of age; n=67), G3 (between one and three months of age; n=75), G4 (between three and six months of age; n=64), G5 (between six and nine months of age; n=59), G6 (between nine and 18 months of age; n=39), and G7 (between 18 months and two years of age; n=17). These groups were statistically analyzed by one-way variance analysis (ANOVA) and Tukey's test. Male and female means were compared by Student's t-test. Hematocrit levels were significantly higher up to 90 days of age and in G7 females. Total plasma proteins increased significantly in groups 3, 4, 6, and 7. The highest fibrinogen levels were found in G1. Yet for creatine phosphokinase, the highest concentrations were detected in G5, whereas those of aspartate aminotransferase in G7. The levels of this enzyme remained similar from 30 days to two years of age. Lactate concentrations were higher in G3. We concluded that the sex of the animal had no significant effect on laboratory test interpretations. By contrast, the age of the animal should be considered since relevant variations were observed with time. Nevertheless, specific tables for each analysis should be consulted for interpretation of results.

Com o propósito de estabelecer valores de hematócrito, proteínas plasmáticas totais, fibrinogênio, creatina quinase , aspartato transferase e lactato em potros da raça Crioula, do nascimento até os dois anos, utilizaram-se amostras sanguíneas de 85 animais, divididos pela estratificação etária: Grupo 1 (G1) Até 15 dias de vida (n=70); grupo 2 (G2), entre 16 dias até um mês (n=67); grupo 3 (G3), entre 1 e 3 meses (n=75); grupo 4 (G4), entre 3 e 6 meses (n=64); grupo 5 (G5), entre 6 e 9 meses (n=59); grupo 6 (G6), entre 9 e 18 meses (n=39); e grupo 7 (G7), entre 18 meses até 2 anos (n=17). Foi realizado estudo estatístico entre os grupos pela análise de variância unidirecional (one-wayANOVA), complementada pelo teste de Tukey. Para comparação das médias entre os sexos utilizou-se o teste t de Student. O hematócrito foi significativamente mais elevado até os 90 dias e nas fêmeas do G7. Para proteínas plasmáticas totais, notou-se aumento significativo nos grupos 3, 4, 6 e 7. Os valores de fibrinogênio foram maiores no G1. A CK apresentou maior concentração no G5 e a AST no G7. A AST assumiu valores semelhantes dos 30 dias até os 2 anos. A concentração de lactato foi mais elevada no G3. Conclui-se que na interpretação dos exames laboratoriais de potros da raça crioula, o gênero não interfere significativamente nos resultados, porém a idade deve ser considerada devido à ocorrência de variações relevantes. Recomenda-se que para interpretação sejam consultadas tabelas específicas para cada análise.

PLASMA SEPARATOR TUBES DO NOT HAVE ANY OVERT EFFECTS ON ROUTINE PLASMA CHEMISTRY DATA OF GREEN SEA TURTLES (CHELONIA MYDAS).

Plasma separator tubes (PSTs) are a variant of lithium heparin blood tube containing a polymer gel, which, when centrifuged, creates a physical barrier between plasma and blood cells. Their use is common in laboratory procedures of reptilian species. This study aimed to determine whether the use of plasma separator tubes impacts plasma biochemistry data in green sea turtles (Chelonia mydas) at time of collection and after 24 hr of contact time with the separator gel after centrifugation at refrigerator temperature. A single blood sample was collected from 42 rehabilitating green sea turtles at the Sea Turtle Healing Center, Brevard Zoo, Melbourne, Florida, USA and divided into one lithium heparin tube [LHT (0 hr)] and two PSTs. After immediate centrifugation of all three tubes, plasma was transferred from the LHT (0 hr) and one PST (0 hr) into tubes without additive. The plasma was left in contact with the separator gel in the second PST (24 hr). After 24 hr of refrigeration, all three plasma aliquots were analyzed for the following 23 analytes: sodium, potassium, chloride, carbon dioxide, calcium, phosphorus, magnesium, iron, total protein, albumin, globulin (calculated), aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase, gamma-glutamyltransferase, creatine kinase, glucose, urea nitrogen, creatinine, uric acid, triglyceride, and cholesterol. No statistically significant differences were found for any biochemical analytes between LHT (0 hr), PST (0 hr), and PST (24 hr). The use of PST does not appear to impact routine plasma biochemical analytes in green sea turtles and analytes appear stable in refrigerated plasma for up to 24 hr after centrifugation when using PSTs.

Transoperative glycemia in pets: validating old ones, and presenting lip mucosa as new sampling site.

The aim of our study was to investigate the viability and validity of blood sampling from the upper lip mucosa in healthy dogs and cats for monitoring transoperative glycemia and compare the results with those obtained from samples taken from previously described blood sampling sites for determination of glycemia using a glucose meter. Blood glucose (BG) levels were determined in samples taken from the upper lip mucosa of 24 dogs and 31 cats undergoing neutering or spaying surgeries. These values were compared to those of samples obtained from other sites previously described for capillary blood glucose monitoring (marginal ear vein, carpal pad in dogs, metacarpal pad in cats) using a glucose meter. Additionally, BG from peripheral venous blood was determined using a glucose meter, and the gold standard enzymatic colorimetric assay. The clinical reliability of BG values taken from lip mucosa and from all the other BG values measured by the glucose meter was evaluated using the error grid analysis modified by Parkes et al (2000). The upper lip mucosa was an easily accessible site for the obtainment of appropriate blood samples, and glucose levels read in these samples correlated positively with glycemic values read in blood samples from all other sites in dogs and cats. All BG made using glucose meters taken from all sites were within the clinically acceptable range when compared with enzymatic colorimetric assay (gold standard), and were analytically accurate according to the error grid (zones A and B). All blood sampling sites described in this work can be used to assess transoperative glycemia. The upper lip mucosa is a viable blood sampling site for precise monitoring of transoperative glycemia in healthy dogs and cats and shows promise for alternative blood glucose monitoring.

Venous blood gas parameters, electrolytes, glucose and lactate concentration in sick neonatal foals: Direct venipuncture versus push-pull technique.

BACKGROUND: Blood collection by indwelling intravenous catheter (IVC) avoids repeated venipuncture, which could cause thrombophlebitis risk, anxiety and pain in patients. OBJECTIVES: To compare blood gas parameters, electrolytes, glucose, lactate and haematocrit concentration obtained from venous blood samples collected via a jugular IVC by push-pull (PP) technique to those obtained by venipuncture in hospitalised foals, at the time of catheter placement (T0) and 24 hours after the beginning of intravenous therapy (T24). STUDY DESIGN: Prospective observational study. METHODS: Paired blood samples were drawn from hospitalised foals at T0 and T24. In each foal, one venous blood sample was collected via IVC by the following PP technique: 2.4 mL of blood was aspirated and immediately reinfused through the catheter three times consecutively, then 1 mL of blood was collected using a 1 mL heparinised syringe. Thereafter, another sample was collected by direct venipuncture of the contralateral jugular vein, with an identical 1 mL heparinised syringe, with a 1-inch, 20-G needle. All samples were analysed with an automated blood gas analyser within 10 minutes of collection. The agreement between the two techniques was assessed by Bland-Altman analysis and intraclass correlation coefficient (ICC). RESULTS: The level of agreement of blood gas values obtained by the two different techniques was high with very small bias and clinically acceptable ICC (>0.907 at T0; >0.794 at T24) for all variables, except for haematocrit (bias -3.52 at T0; -2.44 at T24) and PvO2 at T0 and T24 (ICC 0.669 and 0.733, respectively). MAIN LIMITATIONS: Potential sub-clinical catheter-related complications were not investigated by ultrasound or bacterial culture of the catheter; short duration of the study. CONCLUSIONS: PP technique appears to be acceptable for collection of blood samples for venous blood gas parameters, as well as electrolytes, glucose and lactate in sick neonatal foals.

Clinical assessment of acid-base balance in Netherland Dwarf rabbit / Avaliação clínica do equilíbrio ácido-básico em coelhos Anã Holandês

Pet rabbits have increased their popularity in a lot of countries. However, most of the laboratory profiles in rabbit medicine come from the observations made in rabbit as biomodels or meat production. So that further researches are necessary to obtain reference values for hematology and biochemical profiles in pet rabbits and the different breeds, especially, in relation to acid-base balance. The aim of this report was to offer the mean values of the main parameters connected with acid-base profile in Netherland Dwarf breed. Thirty-five healthy rabbits (15 males and 20 females) were studied. Venous blood sample from lateral saphenous vein was analyzed to measure: haematocrit, haemoglobin, blood urea nitrogen, glucose, blood pH, partial pressure of CO2 (pCO2), total CO2, ions bicarbonate, chloride, sodium, potassium, base excess and anion Gap. Results showed a shorter range that those reported by different researchers. Moreover, differences between genders were showed in pCO2, its values were higher in males. It may be associated with a greater cellular metabolism. Values obtained in this research should be taken into account by veterinary clinicians for this breed in their clinical assessments. Besides, these values provide new results in parameters with few reference values.

A popularidade de coelhos como animais de estimação aumentou em muitos países. No entanto, a maioria dos perfis de laboratório em medicina de coelhos advém das observações de biomodelos animais ou da produção de carne. Assim, são necessárias pesquisas adicionais para obter valores de referência para hematologia e perfis bioquímicos em coelhos de estimação, e das diferentes raças, especialmente, em relação ao equilíbrio ácido-base. O objetivo deste relatório foi oferecer os valores médios dos principais parâmetros ligados ao perfil ácido-base na raça Anã Holandês. Trinta e cinco coelhos saudáveis ​​(15 machos e 20 fêmeas) foram estudados. A amostra de sangue venoso da veia safena lateral foi analisada para mensuração: hematócrito, hemoglobina, nitrogênio ureico sanguíneo, glicose, pH sanguíneo, pressão parcial de CO2 (pCO2), CO2 total, íons bicarbonato, cloreto, sódio, potássio, excesso de base e ânion Gap. Os resultados apresentaram um intervalo menor do que aqueles relatados por diferentes pesquisadores. Além disso, as diferenças entre os gêneros foram mostradas na pCO2, seus valores foram maiores no sexo masculino. Pode estar associado a um maior metabolismo celular. Os valores obtidos nesta pesquisa devem ser levados em consideração pelos clínicos veterinários para esta raça em suas avaliações clínicas. Além disso, esses valores fornecem novos resultados em parâmetros com poucos valores de referencia.

Blood serum stability limit and maximum storage time of bovine samples

Measuring metabolic parameters in the blood has been an indispensable tool for assessing the productive and health status of dairy cows for more than 100 years. The values of laboratory parameters depend on various preanalytical, analytical and postanalytical factors. The most important preanalytical factors are sample transport time and temperature, hemolysis, anticoagulant type, and sample volume. Preanalytical factors can lead to reduced stability of the analyte in the sample, which changes their concentration. Loss of stability changes the time of storage and manipulation of the sample, which determines the criteria for its acceptance or rejection. The two stability indicators are stability limit and maximum permissible instability. A stability limit (SL) is defined as the period of time in which a property variation does not exceed a maximum permissible instability (MPI). The aim of this study was to determine the SL and MPI for each analyte in the blood serum of cows and to determine whether SL differs in the function of the presence of preanalytical errors in the blood sample. Three hundred samples of dairy cow origin in different periods of lactation participated in this research. They were classified into 6 groups of 50 samples: according to the time from sampling to processing in the laboratory (0-4 h, 4-8 h and over 8 h; all transported on dry ice, protected from environmental factors, without preanalytical errors) and according to the presence of preanalytical errors (group with hemolysis, a group transported at ambient temperature and a group with a small sample volume). Each sample was aliquoted in two portions. One portion was left at +4°C and tested once a day for 6 days of sample storage, and the second portion, placed at -20°C, was tested once a month for 6 months. The MPI had a value ranging from 1.51 to 8.4. Metabolic profile analytes with lower MPI values (1.51-3.22) were albumin (ALB), total protein (TPROT), UREA, glucose (GLU), calcium (Ca), and phosphorus (P). Higher MPI values (5.1-8.4) were found for nonesterified fatty acids (NEFA), beta-hydroxybutirate (BHB), cholesterol (CHOL), triglycerides (TGC), total bilirubin (TBIL) and aspartat aminotransferase (AST). For most parameters, we can conclude that their PD% changed faster in storage conditions at +4°C compared to the regime of -20°C. The largest number of biochemical analytes in bovine blood serum shows preserved stability in the first 6 days at +4°C or 6 months at -20°C if transported to the laboratory within 8 h after sampling in ideal conditions and without the action of preanalytical errors. Prolonged transport under ideal conditions or the existence of preanalytical errors such as transport at room temperature, hemolysis or small sample volume shorten the stability of the ALB, NEFA, GLU, UREA and P. Concentration of all analytes decreases during the stability test except for UREA, NEFA, BHB and for CHOL and TGC in some groups. Variations in parameters such as BHB, NEFA, TBIL, AST, and Ca have shown potential clinical significance. At storage conditions at +4°C, clinically significant variations at at least one measurement point were found for AST (7.5% of samples), BHB (6.1% of samples), NEFA (9.9% of samples) and for TBIL (in 7% of samples). This study can help define acceptable delay times and storage conditions for bovine blood samples, which is of great importance because in working with farm animals it is often not possible to take samples in a short time and deliver them to the laboratory, and samples are often burdened with certain preanalytical errors with limited possibilities of re-sampling.(AU)

Using arterial blood as a substitute for venous blood in routine biochemistry parameter examinations in rabbits.

BACKGROUND: It has been widely accepted that there is a significant difference in peripheral blood oxygen between arteries and veins. Therefore, arterial blood has been collected for blood gas analysis, and venous blood, because it is convenient to collect, has been used for most laboratory examinations. However, venous blood is always difficult to collect in rabbits; in contrast, arterial blood is easier to obtain, and research on whether arterial blood can be used instead of venous blood for routine biochemical parameter examination is rare. Therefore, the present study was designed to explore whether arterial blood can be used as a substitute for venous blood for routine biochemistry parameter examination in rabbits. RESULTS: Three venous blood samples with gross hemolysis were excluded. Venous and arterial blood samples were obtained from forty-two rabbits. Arterial blood samples correlate well with venous blood in alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine transaminase (ALT), gamma-glutamyl transpeptidase (GGT), total protein (TP), globulin (GLB), serum total cholesterol (TC), serum triglyceride (TG), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), urea (Ur) and creatinine (Cr) levels by Deming regression analysis with slopes ranging from 0.893 to 1.176 and intercepts ranging from - 4.886 to 5.835. Bland-Altman analysis showed that the two sample parameters had 93%-98% of the points within the 95% consistency limits. There were significant differences between venous blood and arterial blood in ALP, TP, TC, TG, HDL, LDL and Cr, while AST, ALT, GGT, GLB and Ur showed no significant differences. CONCLUSIONS: Arterial blood can be a substitute for venous blood in routine biochemistry parameter examinations in rabbits, especially in situations where venous blood is difficult to collect.

Recovery of hematocrit and fat deposits varies by cage size in food-restricted captive red crossbills (Loxia curvirostra).

Hematocrit-or the percent volume of red blood cells in whole blood-is thought to fluctuate adaptively in response to changing oxygen demands that occur during different life activities and in different environments. Because red blood cells are made from materials that can be limiting, however, it is thought that hematocrit may also reflect general body condition and access to resources. We tested the effect of hydration state, resource restriction (i.e., time available to forage), and activity (i.e., different cage sizes) on hematocrit in captive red crossbills (Loxia curvirostra). We found no evidence that a mild dehydration protocol impacts hematocrit and only weak support that mild food restriction impacts hematocrit. Food restriction did, however, reduce fat deposits and fat loss was more significant in birds that were also sampled for hematocrit. Furthermore, food-restricted birds housed in flight aviaries recovered hematocrit but not fat stores following repeated blood sampling, whereas birds housed in small cages lost additional hematocrit but mitigated fat loss following successive bleeds. Together these results suggest that different flight demands may determine response to blood loss during food restriction, potentially revealing a trade-off between fat storage and red blood cell development. Our results also demonstrate the need for scientists to carefully record hematocrit data and the time course across which multiple tubes of blood are collected to avoid confounding real patterns with variation generated by sampling protocol.

Haematology of Mugil curema from the north coast estuary of Santa Catarina state, Brazil / Hematologia de Mugil curema em estuário no litoral norte do estado de Santa Catarina, Brasil

Mugil curema is a teleost fish often found in coastal, estuarine and lagoon regions throughout the Brazilian coast. Blood parameters may be used as health and welfare indicators of the fish, as well as the environment they live in. The aim of this study was to verify the hematologic profile of the M.curema along 18 months in estuary waters from the north coast of the state of Santa Catarina in the south of Brazil. A total of 133 M. curema fish were captured from March 2016 to August 2017. Erythrogram, leukogram, thrombocytogram, hematocrit percentage, hemoglobin dosage, total plasma protein dosage, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and medium corpuscular hemoglobin concentration (MCHC) were analyzed. There was no significant difference (P>0.05) on the total number of erythrocytes between the fish gender. However, there was difference on the hematocrit between males and indefinite gender fish. The influences of temporal and geographical space, among the values of hematological parameters, in the different studies of the Brazilian coast are discussed.. The present research is an important contribution to establish a hematological pattern for M. curema. The local population of the studied fish has a proper behavior in hematological descriptors, which is different from other Brazilian coast studies with the same fish species.

Mugil curema é um peixe teleósteo, abundante em regiões costeiras, estuarinas e lagunares, em todo o litoral brasileiro. Os parâmetros sanguíneos podem ser usados como indicadores da saúde e do bem-estar dos peixes, bem como do ambiente onde estes vivem. O objetivo deste estudo foi verificar o perfil hematológico de M. curema ao longo de 18 meses, em águas estuarinas, no Litoral norte do estado de Santa Catarina, sul do Brasil. Um total de 133 peixes foram capturados, entre março de 2016 e agosto de 2017, para realização de eritrograma, leucograma, trombocitograma, porcentagem de hematócrito, dosagem de hemoglobina, dosagem de proteína plasmática total, volume corpuscular médio (VCM), hemoglobina corpuscular média (HCM) e concentração de hemoglobina corpuscular média (CHCM). Não houve diferença significativa (P>0,05) entre o número total de eritrócitos entre machos e fêmeas. No entanto, houve diferença no hematócrito, entre machos e peixes de sexo indeterminado. As influências do espaço temporal e geográfico, entre os valores dos parâmetros hematológicos, nos diferentes estudos do litoral brasileiro são discutidas. A presente investigação é importante contribuição para o estabelecimento de um padrão hematológico para M. curema. A população local de peixes estudada tem comportamento próprio em descritores hematológicos, diferenciado de outros estudos no litoral brasileiro para a mesma espécie.

Effect of pH and storage conditions on measured ionised calcium concentration in dogs and cats.

BACKGROUND: Aerobic blood sample collection and processing results in increased serum pH and decreased ionised calcium (iCa) concentration. This prospective study aimed to determine the effect of pH and storage conditions on measured iCa concentration in serum samples obtained from dogs and cats and establish correction formulas for use in samples obtained aerobically. METHODS: Blood samples were collected from 44 dogs and 25 cats; iCa and pH were measured immediately under anaerobic conditions and in samples stored under several aerobic conditions. RESULTS: Measured iCa concentrations were significantly lower in samples stored at all aerobic conditions than in samples handled anaerobically in both dogs and cats (P<0.01 for all). The largest and most clinically significant differences were noted in samples stored at -20°C for 30 days in both dogs (0.48 mmol/l; 95 per cent CI 0.40 to 0.55) and cats (0.40 mmol/l; 95 per cent CI 0.33 to 0.47). Correction formulas (corrected iCa=measured iCa+coefficient × (measured pH-7.41); coefficient=0.597 for dogs, 0.627 for cats) yielded good agreement between the corrected and the actual iCa concentrations. CONCLUSIONS: Samples for iCa measurement can be stored at either 4°C or -20°C for 24 hours. Storage at -80°C is recommended for longer storage time periods.

Electrolyte measurement in goats: Comparison of 2 blood gas analyzers and evaluation of the preanalytical blood sample preparation on measurement results.

OBJECTIVE: 1) To evaluate agreement for electrolyte measurements in goats between a handheld point-of-care analyzer (Abaxis VetScan i-STAT 1) (POC) and a benchtop blood gas analyzer (Opti CCA-TS2) (VBG) and 2) to evaluate effect of sample type on electrolytes values reported by both analyzers. MATERIAL AND METHODS: In 21 hospitalized caprine patients and 9 healthy research goats, blood samples were collected into heparin-containing tubes (Sodium Heparin 33 IU/2 ml) (TUBE) and a heparinized syringe (Sodium Heparin 430 IU/ml) (SYRINGE). Samples were analyzed using a POC analyzer as well as VBG. Analyzer results were compared using Bland-Altman analysis and Pearson correlation. Comparison between samples was performed using repeated measures ANOVA. RESULTS: Between analyzers, TUBE yielded a bias (95 % limits of agreement) of 0.07 mmol/l (-4.37 to 4.52) for sodium, while SYRINGE yielded a bias of -6.13 mmol/l (-11.04 to -1.22). Comparison of potassium yielded a bias of 0.09 mmol/l (-0.5 to 0.67) and 0.08 mmol/l (-0.4 to 0.56) for TUBE and SYRINGE, respectively. Comparison of ionized calcium showed a bias of 0.05 mmol/l (0.01-0.1) and -0.02 mmol/l (-0.18 to 0.14) for TUBE and SYRINGE, respectively. Between sample types, the POC yielded a bias of 5.13 mmol/l (0.18-10.09) for sodium, 0.04 mmol/l (-0.12 to 0.2) for potassium, and 0.40 mmol/l (0.12-0.68) for ionized calcium. CONCLUSION AND CLINICAL RELEVANCE: The POC exhibited clinically negligible bias for electrolyte analysis as compared to VBG. Ionized calcium concentrations were lower in self-prepared heparinized syringes than in heparin-containing tubes, suggesting an effect of heparin concentration on ionized calcium.