Invalid measurement of plasma albumin using bromcresol green methodology in penguins (Spheniscus species)

Packed Cell Volume and Plasma Chemistry Reference Intervals for Eurasian Eagle Owls (Bubo bubo) in a Rehabilitation Setting in South Korea before Release

Rehabilitation and release of wild birds hinge upon a comprehensive understanding of both biologic and nonbiologic factors, including the medical and physical fitness of the animal. The objectives of this study were to determine reference intervals of packed cell volume and plasma chemistry values for healthy Eurasian Eagle Owls (Bubo bubo) and to compare blood values between age and sex classes. There were significant differences between males and females in total protein and globulin mean values, with males having higher values than females. Adult and juvenile Eagle Owls differed significantly in the mean values of calcium, alkaline phosphatase, and uric acid, with juveniles having higher values than adults. The calculated reference intervals for Eagle Owls can be used in Eurasian Eagle Owls admitted to rescue centers to assist veterinarians and wildlife managers to clinically evaluate and monitor the health of Eagle Owls and make decisions about when to release them after treatment.

Capillary Zone Electrophoresis in Humboldt Penguins (Spheniscus humboldti)

Electrophoresis is a useful diagnostic tool for detecting inflammation, including inflammation associated with infectious diseases (eg, aspergillosis in penguins). To our knowledge, reference intervals are not available for plasma proteins via electrophoresis in Humboldt penguins (Spheniscus humboldti). Therefore, preliminary reference intervals for blood plasma proteins measured by capillary zone electrophoresis were calculated for Humboldt penguins from a single zoological collection, and possible differences between the sexes and the ages of the birds were evaluated. Lithium heparinized plasma samples from 39 Humboldt penguins were analyzed. The following sex- and age-independent reference intervals were calculated: total protein 33.8-70.4 g/L, prealbumin 1.9-4.9 g/L, albumin 12.9-31.1 g/L, albumin: globulin ratio 0.7-1.7, α-globulins 4.5-11.6 g/L, β-globulins 5.6-20.6 g/L, and γ-globulins 2.6-8.4 g/L. Male penguins had a significantly (P = 0.047) higher albumin: globulin ratio and lower percentage of β-globulins (P = 0.015) in comparison with female penguins. Prealbumin (g/L) significantly (P = 0.021) decreased with increased age of the penguins. These results showed some differences between the sexes and ages of the penguins, which should be considered when interpreting the results. Further studies are needed to determine whether differences in other age groups or seasons exist, and also to evaluate which infectious diseases affect plasma proteins and how the reference values calculated here may deviate in ill penguins.

Avian Inflammatory Markers

Inflammation represents a fundamental response to diverse diseases ranging from trauma and infection to immune-mediated disease and neoplasia. As such, inflammation can be a nonspecific finding but is valuable as an indicator of pathology that can itself lead to disease if left unchecked. This article focuses on inflammatory biomarkers that are available and clinically useful in avian species. Inflammatory biomarkers are identified via evaluation of whole blood and plasma and can be divided into acute and chronic, with varying degrees of specificity and sensitivity. Evaluation of multiple biomarkers may be necessary to identify subclinical disease.

Challenges to establish the diagnosis of aspergillosis in non-laboratory animals: looking for alternatives in veterinary medicine and demonstration of feasibility through two concrete examples in penguins and dolphins

Aspergillosis remains difficult to diagnose in animals. Laboratory-based assays are far less developed than those for human medicine, and only few studies have been completed to validate their utility in routine veterinary diagnostics. To overcome the current limitations, veterinarians and researchers have to propose alternative methods including extrapolating from human diagnostic tools and using innovative technology. In the present overview, two specific examples were complementarily addressed in penguins and dolphins to illustrate how is challenging the diagnosis of aspergillosis in animals. Specific focus will be made on the novel application of simple testing in blood based on serological assays or protein electrophoresis and on the new information garnered from metabolomics/proteomics to discover potential new biomarkers. In conclusion, while the diagnostic approach of aspergillosis in veterinary medicine cannot be directly taken from options developed for human medicine, it can certainly serve as inspiration.

Establishment of reference intervals for plasma protein electrophoresis and comparison of biochemical and protein electrophoresis evaluation of albumin in central bearded dragons (Pogona vitticeps)

The aim of this study is to develop a reference interval for plasma protein electrophoresis for wild free-roaming central bearded dragons (Pogona vitticeps). This will assist the veterinarian in diagnosing and monitoring diseases in wild and captive animals. The study group consisted of 29 wild central bearded dragons of which 22 were males and 7 were females. The plasma samples were obtained from animals in a previous study and were stored frozen at -20°C for 2-3 years before analysis. Plasma protein electrophoresis was performed on 100 uL of plasma. The data were evaluated for the difference between reproductively active females and pooled males with non-reproductively active females as well as the difference between biochemical and protein electrophoresis albumin. Biochemical albumin was found to be significantly higher than electrophoresis albumin in all animals, with a mild proportional bias present. Plasma protein electrophoresis identified albumin, α - 1 and 2, β - 1 and 2 and γ fractions. The reproductively active females in this study exhibited results that were distinct from pooled males and non-reproductively active females. This study provides a reference interval for plasma protein electrophoresis in central bearded dragons that can be used as a tool for health and disease monitoring and diagnosis. The importance of the use of method and sex/season appropriate reference intervals in reptile medicine is confirmed in this study.

Protein electrophoresis of non-traditional species: A review

EPH has been demonstrated to be a useful tool in companion animals while providing an opportunity to characterize globulinemias, including paraproteinemia. In EPH of non-traditional species, these same applications are important, but the primary use is to gauge the acute-phase and humoral immune responses. This includes the valid quantitation of albumin as well as the examination of fractions reflective of increases in acute-phase reactants and immunoglobulins. Agarose gel EPH and, more recently, capillary zone EPH have been applied to samples from these species. Performing these analyses provides special challenges in the placement of fraction delimits, generation of RIs, and interpretation of results. Recommended as part of routine bloodwork, EPH can also provide key results that are helpful in clinical and field-based health assessments as well as in prognostication.

Comparison of Capillary Zone Electrophoresis in Greater Flamingos (Phoenicopterus roseus) and American Flamingos (Phoenicopterus ruber)

Electrophoresis can be used to aid in the diagnosis of infectious diseases (eg, aspergillosis) in avian species. Reference intervals for blood plasma proteins of 2 different flamingo species (Phoenicopterus roseus and Phoenicopterus ruber) and their hybrids were calculated by capillary zone electrophoresis (CZE) and differences between these species, sexes, and age groups were evaluated. Lithium-heparinized plasma samples from 111 animals from a zoological collection were analyzed by CZE and statistically evaluated. Differences were only found between greater and American flamingos (P = .003) and between greater flamingos and hybrids (P = .001) in the γ-globulin fraction. Male greater flamingos showed significantly higher α-globulins (P = .022) and females higher total albumin by CZE (P = .037). In American flamingos, the percent total albumin (P = .017), total albumin (P = .025), prealbumin (P = .005), and albumin/ globulin (A/G) ratio (P = .008) were higher in females, and α- (P = .023) and β-globulins (P = .021) were higher in males of the same species. The following parameters differed significantly between the age groups: γ-globulins (P = .048) in greater and α- (P = .021) and β-globulins (P = .001) in American flamingos increased with increased age and percent total albumin (P = .002), total albumin (P = .024), and A/G ratio (P = .002) decreased with age in American flamingos. The results showed only small differences between the species, but greater differences between the sexes and ages, especially in American flamingos, which must be considered when interpreting laboratory results.

COMPARISON OF PROTEIN ELECTROPHORESIS AND BIOCHEMICAL ANALYSIS FOR THE QUANTIFICATION OF PLASMA ALBUMIN IN HEALTHY BEARDED DRAGONS (POGONA VITTICEPS)

While electrophoresis is considered the standard method for evaluation of protein concentrations as a result of its direct measurement, albumin is often quantified with biochemical assays. Many laboratory-based chemistry analyzers and clinic-based point-of-care analyzers use the dye bromocresol green (BCG) for the quantitation of albumin. Several studies have shown that albumin concentrations obtained by the standard (BCG) dye-binding method are significantly different from those obtained by protein electrophoresis in avian species and chelonia. The goal of this study was to compare plasma albumin concentrations obtained by the BCG method with those derived from electrophoresis in bearded dragons (Pogona vitticeps). Thirty-six heparinized plasma samples were obtained from 13 clinically healthy male bearded dragons. Albumin was quantified by protein electrophoresis and by the BCG dye-binding method. The two methods were significantly different (P < 0.0001, paired t-test; P < 0.0001, Wilcoxon signed-rank test), with the BCG measurement always equal to or higher than the electrophoretic result. The measurements from both methods were significantly correlated (r = 0.8634, P < 0.0001), but concordance between the two techniques was poor. The Bland-Altman plot appeared to show a greater difference between the two measurements with lower albumin values and lesser difference with higher values. These results indicate that bearded dragon plasma albumin concentration measurements obtained by the BCG dye-binding method are unreliable when compared to those obtained with electrophoresis, suggesting that albumin should be measured by protein electrophoresis for health assessment in bearded dragons.

PLASMA BIOCHEMISTRY AND PROTEIN ELECTROPHORESIS REFERENCE INTERVALS OF THE COMMON LOON (GAVIA IMMER)

There are no published plasma biochemistry reference intervals for any species within the order Gaviiformes, which includes the common loon (Gavia immer). Because of their unique classification and lack of close taxonomic relatives, species-specific values for clinical data in loons are needed. This study determined reference intervals for plasma biochemical values in adult common loons, and reference intervals for protein electrophoresis values in both adult and juvenile common loons. Healthy, wild adult (n = 148, age >3 yr) and juvenile (n = 31, age 4-12 wk) common loons were sampled on freshwater summer breeding territories at study sites across North America. Plasma biochemical analytes included glucose (Glu), total calcium, phosphorus, sodium, potassium, chloride, blood urea nitrogen (BUN), uric acid, cholesterol, triglycerides, creatine kinase, γ-glutamyl transferase, alkaline phosphatase (ALP), lactate dehydrogenase, aspartate aminotransferase, amylase, and bile acids. Protein electrophoresis data included albumin to globulin ratio (A: G), prealbumin, albumin, α1-globulin, α2-globulin, β-globulin, and γ-globulin. Adult females had significantly higher Glu, ALP, and BUN than adult males. Juvenile loons had higher β-globulins than adults, whereas adults had higher α1-globulins. Establishment of complete reference intervals will improve clinical assessment of captive loons, and allow researchers to better understand the health of wild loons in response to the multiple environmental stressors faced by these species.

Systemic Helicobacter infection and associated mortalities in endangered Grand Cayman blue iguanas (Cyclura lewisi) and introduced green iguanas (Iguana iguana)

The Blue Iguana Recovery Programme maintains a captive breeding and head-starting program for endangered Grand Cayman blue iguanas (Cyclura lewisi) on Grand Cayman, Cayman Islands. In May 2015, program staff encountered two lethargic wild Grand Cayman blue iguanas within the Queen Elizabeth II Botanic Park (QEIIBP). Spiral-shaped bacteria were identified on peripheral blood smears from both animals, which molecular diagnostics identified as a novel Helicobacter species (provisionary name Helicobacter sp. GCBI1). Between March 2015 and February 2017, 11 Grand Cayman blue iguanas were identified with the infection. Two of these were found dead and nine were treated; five of the nine treated animals survived the initial infection. Phylogenetic analysis of the 16S rRNA gene suggests Helicobacter sp. GCBI1 is most closely related to Helicobacter spp. in chelonians. We developed a Taqman qPCR assay specific for Helicobacter sp. GCBI1 to screen tissue and/or blood samples from clinical cases, fecal and cloacal samples from clinically healthy Grand Cayman blue iguanas, including previously infected and recovered iguanas, and iguanas housed adjacent to clinical cases. Fecal and/or cloacal swab samples were all negative, suggesting that Grand Cayman blue iguanas do not asymptomatically carry this organism nor shed this pathogen per cloaca post infection. Retrospective analysis of a 2014 mortality event affecting green iguanas (Iguana iguana) from a separate Grand Cayman location identified Helicobacter sp. GCBI1 in two of three cases. The source of infection and mode of transmission are yet to be confirmed. Analysis of rainfall data reveal that all infections occurred during a multi-year dry period, and most occurred shortly after the first rains at the end of seasonal drought. Additionally, further screening has identified Helicobacter sp. GCBI1 from choanal swabs of clinically normal green iguanas in the QEIIBP, suggesting they could be asymptomatic carriers and a potential source of the pathogen.

COMPARISON OF AGAROSE GEL AND CAPILLARY ZONE ELECTROPHORESIS METHODS USING PLASMA FROM GREEN TURTLES (CHELONIA MYDAS)

Agarose gel electrophoresis (AGE) has been widely implemented throughout veterinary medicine and for analysis of plasma proteins of avian and reptile species. Capillary zone electrophoresis (CZE) is becoming a standard method in human clinical pathology laboratories but has not widely been used for the analysis of animal samples. The objective of the present study was to compare protein fractions derived from AGE and CZE methods using plasma from the green turtle (Chelonia mydas). Plasma samples were analyzed by AGE and CZE per manufacturer guidelines. The methods were assessed by CV analysis, Spearman's correlation, Passing-Bablok regression, and Bland Altman plots. CZE consistently resolved more fractions than AGE with three fractions observed in the prealbumin migrating region versus one for AGE and two fractions in the γ globulin region versus one for AGE. Compared with AGE, CZE showed a lower CV in intra-assay tests (1.0-4.9% vs 2.0-28.3%) and a lower or overlapping CV in interassay tests (1.0-10.6 vs 2.3-22.0). The prealbumin, α2 globulin, and β globulin fractions correlated the least between the methods (for all three fractions: r_s ≤ 0.28, P > 0.21). Moderate, significant correlations between AGE and CZE methods were observed for albumin (r_s = 0.78, P < 0.0001) and γ globulins (r_s = 0.78, P < 0.0001). CZE has a higher precision and ease of use over AGE and offers the opportunity to resolve additional protein fractions. This will necessitate the development of new conventions in placement of fraction delimits, definition of species-specific reference intervals, and evaluation of clinical utility in abnormal turtles.

Bias between two methods of albumin measurement in the white rhinoceros, Ceratotherium simum

BACKGROUND

The bromocresol green (BCG) method has been reported to overestimate serum albumin concentration in several species due to non-specific binding to globulins. As the white rhinoceros has high concentrations of serum globulins, significant differences in albumin measured by the BCG method, and the field method of agarose gel serum protein electrophoresis (SPE) are expected.

OBJECTIVES

We aimed to compare the BCG and SPE methods for albumin determination in the serum of white rhinoceroses.

METHODS

SPE and BCG albumin were measured in 82 white rhinoceros serum samples. Results were compared using Bland-Altman difference plots and Passing-Bablok regression analysis.

RESULTS

BCG albumin showed a significant mean constant positive bias of 7 g/L, or 36%, which was more than the total allowable error of 15% and was clinically significant. Methods were not comparable within the inherent imprecision of each method.

CONCLUSIONS

The BCG method overestimated albumin concentrations in this species compared with agarose gel SPE, and method-specific reference intervals should be used.

APPLICATION OF 3-HYDROXYBUTYRATE MEASUREMENT AND PLASMA PROTEIN ELECTROPHORESIS IN THE DIAGNOSIS OF ASPERGILLOSIS IN AFRICAN PENGUINS ( SPHENISCUS DEMERSUS)

New alternative laboratory means are needed to improve the options for antemortem diagnosis of avian aspergillosis. In this study, 3-hydroxybutyrate was measured in plasma samples collected from a cohort of African penguins ( Spheniscus demersus) maintained under human care. Results were interpreted in combination with those of protein electrophoresis and compared with anti- Aspergillus antibody and galactomannan antigen detection. Overall, 3-hydroxybutyrate levels were found significantly increased in Aspergillus-diseased cases versus the control penguin group ( P = 0.002). Mean absolute concentration of β-globulins was increased >20% in samples from infected birds, and α2-globublins were also found to be significantly increased versus clinically normal controls ( P < 0.001 and P = 0.001 respectively). Of note, the α2-globulins were also significantly increased versus penguins with inflammatory (non-aspergillosis) diseases ( P = 0.001). The specificity of 3-hydroxybutyrate, β-globulins, and α2-globulins for aspergillosis was 78.6%, 79.6%, and 92.2%, respectively. Using these measures in tandem resulted in high specificity (>90%) and negative predictive value (≥80%). In contrast, anti- Aspergillus antibody and galactomannan antigen did not distinguish between infected cases and controls ( P > 0.05). This study demonstrates that basic testing in tandem with the new biomarker 3-hydroxybutyrate may provide reliable evidence for the diagnosis of aspergillosis in penguins.

Clinical biochemistry of rescued Magellanic Penguins (Spheniscus magellanicus): serum or heparinized plasma?

ABSTRACT In the last few years, an increasing number of debilitated Magellanic penguins (Spheniscus magellanicus) has been rescued and taken to rehabilitation centers on Brazil’s southern coast to be clinically treated and evaluated for re-introduction. This work aims to compare the viability of heparinized plasma with the viability of serum for biochemistry analyses under rehabilitation conditions. Blood sampled from 31 physically healthy rescued penguins was processed into serum/plasma-paired samples and analyzed for 12 biochemical parameters: alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), cholesterol (CHOL), creatine kinase (CK), gamma-glutamyl transpeptidase (GGT), glucose, (GLU) lactate dehydrogenase (LDH), total proteins (TP), triglycerides (TG), urea (UR), and uric acid (UA).The results showed that six paired samples presented visual signs of hemolysis (visual hemolytic score≥1), four of which occurred exclusively in the serum counterpart. Significant differences (P≤ 0.5) between sample types were found for CHOL (3%), GLU (6%) and TG (52%). Only TG was considered clinically relevant (>10%). All mean/median results fell within the available reference intervals by the Association of Zoos and Aquariums (Penguin, 2014). In conclusion, we verified that heparinized plasma is a viable sample for the clinical biochemistry of rescued Magellanic penguins as it yields compatible results with serum, while providing practical benefits. The adoption of this practice favors a faster bird recovery, by minimizing blood sampling volume, and optimizes material resources, allowing use of the same collector tube as for hematology.

Plasma protein electrophoresis as a prognostic indicator in Aspergillus species-infected Gentoo penguins (Pygoscelis papua papua)

BACKGROUND

Avian aspergillosis presents a significant threat to captive penguin populations. Currently, a lack of objective prognostic factors limits disease staging, objective reassessment throughout treatment, comparative evaluation of treatment regimes, and appropriate timing of euthanasia.

OBJECTIVE

The study objective was to investigate absolute and relative plasma protein fractions by agarose gel electrophoresis (EPH) as predictors of survival in Gentoo penguins (Pygoscelis papua papua) under treatment for aspergillosis.

METHODS

One hundred and eighty-three EPH profiles from individual clinical cases were examined retrospectively. Animal survival to 90 days post sampling was established from clinical records; birds either survived (n = 146) or died within 90 days (n = 37), and time to death was recorded.

RESULTS

Fourteen variables showed statistically significant differences (P < .05) between surviving and dying birds. Receiver operating characteristic curve analysis identified total albumin concentration (albumin + prealbumin) and albumin-to-globulin (A:G) ratio as having strongest discriminatory values (95% CI) at 0.788 (0.710-0.866) and 0.784 (0.696-0.871), respectively. Albumin (concentration and percentage of total protein) displayed moderate discriminatory value but additionally a weak positive correlation with time to death (95% CI); r = .353 (0.033-0.608) and .424 (0.116-0.658), respectively.

CONCLUSIONS

Optimized test cutoffs for total albumins, albumin (concentration and percentage of total protein), and A:G ratio achieved moderate sensitivity and specificity, strong negative predictive values, but weak positive predictive values due to a low prevalence of death. Selection of appropriate test cutoff values may provide valuable adjunctive prognostic tools for clinical decision-making when the prognosis is difficult to assess clinically.

PLASMA PROTEIN ELECTROPHORESIS AND SELECT ACUTE PHASE PROTEINS IN HEALTHY BONNETHEAD SHARKS (SPHYRNA TIBURO) UNDER MANAGED CARE

Preventative health care of elasmobranchs is an important but understudied field of aquatic veterinary medicine. Evaluation of inflammation through the acute phase response is a valuable tool in health assessments. To better assess the health of bonnethead sharks ( Sphyrna tiburo ) under managed care, normal reference intervals of protein electrophoresis (EPH) and the acute phase proteins, C-reactive protein (CRP) and haptoglobin (HP), were established. Blood was collected from wild caught, captive raised bonnethead sharks housed at public aquaria. Lithium heparinized plasma was either submitted fresh or stored at -80°C prior to submission. Electrophoresis identified protein fractions with migration characteristics similar to other animals with albumin, α-1 globulin, α-2 globulin, β globulin, and γ globulin. These fractions were classified as fractions 1-5 as fractional contents are unknown in this species. Commercial reagents for CRP and HP were validated for use in bonnethead sharks. Reference intervals were established using the robust method recommended by the American Society for Veterinary Clinical Pathology for the calculation of 90% reference intervals. Once established, the diagnostic and clinical applicability of these reference intervals was used to assess blood from individuals with known infectious diseases that resulted in systemic inflammation and eventual death. Unhealthy bonnethead sharks had significantly decreased fraction 2, fraction 3, and fraction 3:4 ratio and significantly increased fraction 5, CRP, and HP. These findings advance our understanding of elasmobranch acute phase inflammatory response and health and aid clinicians in the diagnosis of inflammatory disease in bonnethead sharks.

Blood Biochemical Values of Wild Scarlet Macaw ( Ara macao macao) Nestlings and Adults

Blood biochemical values are useful as indicators of disease in veterinary practice and for health assessments of free-ranging animal populations. We analyzed blood biochemical values for free-living nestling and adult scarlet macaws ( Ara macao macao) in southeastern Peru with an Abaxis VetScan VS2 portable analyzer with Avian/Reptilian Profile Plus rotors. The resulting data were used to create provisional age-independent reference intervals for this instrument for wild scarlet macaw nestlings, calculate blood biochemical ranges for this instrument for wild adults, and examine age-related trends in nestlings. Levels of 11 parameters were studied: albumin, aspartate aminotransferase, calcium, creatine kinase, globulin, glucose, phosphorus, potassium, total protein, sodium, and uric acid. Bile acid levels were generally below the instrument detection level and were not evaluated. Most values and their trends with bird age were comparable to those observed in captive large macaw nestlings. Albumin, aspartate aminotransferase, globulin, glucose, total protein, sodium, and uric acid levels increased with nestling age to adulthood. Creatine kinase, phosphorus, and potassium concentrations decreased with age to adulthood. Calcium concentrations did not change between nestlings and adults. These changes in values with age are broadly in agreement with values in other avian species and likely reflect physiologic and developmental changes as nestlings mature.

HEMATOLOGY AND BIOCHEMISTRY IN CAPTIVE WHITE-NAPED CRANES (GRUS VIPIO)

In this retrospective study, 36 hematologic and biochemistry samples from white-naped crane (Grus vipio) were analyzed. All birds were housed at a single institution, and samples were obtained between 1990 and 2013. All cranes were healthy at the time of sample collection, and ages ranged from 1 mo to 33 yr old. Cranes below 18 mo old were considered juveniles. Comparisons were made between means for juveniles and adults and for males and females. Significant increases in adults (P < 0.05) were found in the following variables (differences shown in parentheses): packed cell volume (8.3%), mean cell volume (28 fl), monocyte percentage (3.2%), absolute monocyte count (200 × 10³/ml), total solids (1.0 g/dl), albumin (0.5 g/dl), and sodium (3 mM/L). Significant decreases in adults (P < 0.05) were found in phosphorus (1.7 mg/dl), creatine phosphokinase (1,146 U/L), alkaline phosphatase (451 U/L), lactate dehydrogenase (149 U/L), and glucose (25 mg/dl). Results from adult male and female cranes were also compared; calcium levels were higher in females (4.68 mg/dl, P < 0.05). Plasma electrophoresis and radioimmunoassay for bile acids were performed on 25 banked serum or plasma samples; results from juvenile and adult samples were also compared. Significant increases in adult birds were found in total protein (1.2 g/dl, P < 0.05) and in all absolute values for all protein types; however, no difference was found when protein fractions were compared. Bile acids were found to decrease in adults (19.9 μM/L, P < 0.05).

Impact of Delayed Analysis in Avian Blood Biochemical Values Measured With the Abaxis VetScan VS2

For biochemical analysis with a point-of-care biochemical analyzer, standard procedure is to analyze the sample as rapidly as possible (<1 hour) after venipuncture to minimize any changes in analyte concentrations that might occur over time. However, under some circumstances, such as when collecting blood at remote field sites, a longer delay may be unavoidable. This study evaluates the effect of delayed analysis time under unrefrigerated conditions on avian (psittacine) biochemical analyte concentrations obtained with the VetScan VS2 using Avian/Reptilian Profile Plus rotors. Venipuncture was performed on a group of 36 psittacine birds as part of routine health checks in a research aviary (Texas A&M University, College of Veterinary Medicine, College Station, TX, USA). Whole blood was kept at room temperature and analyzed at 4 time intervals: <1, 3, 6, and 24 hours after venipuncture. At 3 hours or less after collection, most biochemical parameters changed by <2%, with the exception of phosphorus (decrease of about -9%). Major increases by 24 hours after collection were observed in phosphorus (+67%) and potassium (+103%) concentrations, whereas aspartate aminotransferase (AST), uric acid, glucose, and sodium concentrations also showed statistically significant changes. Our results suggest that accurate information from analyses using the VetScan VS2 may be obtained for up to 3 hours after venipuncture without refrigeration, but researchers and clinicians do need to exercise care when interpreting blood chemistry analyte concentrations obtained after multihour delays between venipuncture and sample analysis.

Protein and cholesterol electrophoresis of plasma samples from captive cownose ray (Rhinoptera bonasus)

Our study was undertaken to assess the application of semiautomated methods available at the reference laboratory level for the evaluation of plasma protein and cholesterol via electrophoresis in samples from cownose rays ( Rhinoptera bonasus). Three groups of animals were assessed: clinically normal, clinically abnormal, and parasitized with leeches. As reported previously, the albumin band was negligible; the protein electrophoretograms were dominated by a large beta-globulin fraction. While the group of samples from the leech-parasitized rays did not show any large differences, the abnormal group exhibited significantly elevated total solids and cholesterol levels. The latter was related to a significant increase in very low density lipoprotein levels. The results demonstrate the potential application of these laboratory methods in quantitation of plasma proteins and cholesterol fractions in subclass Elasmobranchii.

Evaluating the stress response as a bioindicator of sub-lethal effects of crude oil exposure in wild house sparrows (Passer domesticus)

Petroleum can disrupt endocrine function in humans and wildlife, and interacts in particularly complex ways with the hypothalamus-pituitary-adrenal (HPA) axis, responsible for the release of the stress hormones corticosterone and cortisol (hereafter CORT). Ingested petroleum can act in an additive fashion with other stressors to cause increased mortality, but it is not clear exactly why--does petroleum disrupt feedback mechanisms, stress hormone production, or both? This laboratory study aimed to quantify the effects of ingested Gulf of Mexico crude oil on the physiological stress response of house sparrows (Passer domesticus). We examined baseline and stress-induced CORT, negative feedback, and adrenal sensitivity in house sparrows given a 1% oil or control diet (n = 12 in each group). We found that four weeks on a 1% oil diet did not alter baseline CORT titers or efficacy of negative feedback, but significantly reduced sparrows' ability to secrete CORT in response to a standardized stressor and adrenocorticotropin hormone injection, suggesting that oil damages the steroid-synthesizing cells of the adrenal. In another group of animals on the same 1% oil (n = 9) or control diets (n = 8), we examined concentrations of eight different blood chemistry parameters, and CORT in feathers grown before and during the feeding experiments as other potential biomarkers of oil exposure. None of the blood chemistry parameters differed between birds on the oil and control diets after two or four weeks of feeding, nor did feather CORT differ between the two groups. Overall, this study suggests that the response of CORT to stressors, but not baseline HPA function, may be a particularly sensitive bioindicator of sub-lethal chronic effects of crude oil exposure.

Hematologic and plasma biochemical reference values of the horned guan, Oreophasis derbianus

The horned guan (Oreophasis derbianus) is an endangered species with small and seriously fragmented wild populations. Breeding efforts during the last decade have maintained a slowly increasing captive population with the potential to play an important role in the recovery of the species. Clinical hematology and biochemistries are powerful tools to diagnose and monitor diseases in captive birds. Therefore, establishing hematologic and plasma biochemistry reference values will improve the medical management of this species. This study determines the reference values for 9 hematologic and 15 plasma biochemical variables for 27 male and 12 female, apparently healthy, captive horned guans from three institutions. Differences related to age, sex, and husbandry were identified but were usually small and clinically insignificant. These results should improve veterinary care of captive individuals of this species and provide comparative data for other species of cracids.

Acute phase proteins in animals

Acute phase proteins (APP) were first identified in the early 1900s as early reactants to infectious disease. They are now understood to be an integral part of the acute phase response (APR) which is the cornerstone of innate immunity. APP have been shown to be valuable biomarkers as increases can occur with inflammation, infection, neoplasia, stress, and trauma. All animals--from fish to mammals--have demonstrable APP, but the type of major APP differs by species. While the primary application of these proteins in a clinical setting is prognostication, studies in animals have demonstrated relevance to diagnosis and detection and monitoring for subclinical disease. APP have been well documented in laboratory, companion, and large animals. With the advent of standardized and automated assays, these biomarkers are available for use in all fields of veterinary medicine as well as basic and clinical research.