Comparison of two analyzers to determine selected venous blood analytes of Quaker parrots (Myiopsitta monachus)

HEALTH ASSESSMENT OF BLUE-FOOTED BOOBIES (SULA NEBOUXII EXCISA) DETERMINED BY HEMATOLOGY, BIOCHEMISTRY, BLOOD GASES, AND PHYSICAL EXAMINATION IN THE GALÁPAGOS ISLANDS

The Galápagos blue-footed booby (Sula nebouxii excisa) is a sulid species endemic to the Galápagos archipelago. Here we present physical examination, breeding status, hematology, and blood chemistry results from 60 Galápagos blue-footed boobies that were captured by hand from their nesting site on North Seymour Island in June 2017 and July 2022. A portable blood analyzer (iSTAT) was used to obtain values in the field for hematocrit, hemoglobin, sodium, potassium, chloride, ionized calcium, total CO2, glucose, blood urea nitrogen, creatinine, and anion gap for each bird. Blood lactate, total solids, packed cell volume, and blood smears were also assessed. A white blood cell differential was performed in 2017. The breeding status of each bird and the number of chicks in the nests were also recorded. Total CO2, blood urea nitrogen, ionized calcium, potassium, anion gap, hematocrit, and hemoglobin were all higher in 2022 than in 2017. There were also more nests with chicks in 2022 than in 2017. Lactate, ionized calcium, hematocrit, and hemoglobin were all higher in females than in males, and blood urea nitrogen was higher in males than in females. These results provide a reference to the baseline health parameters in a free-living population of Galápagos blue-footed boobies that can be used to monitor the health status of this species.

Health status and morphometrics of Galápagos magnificent frigatebirds (Fregata magnificens magnificens) determined by hematology, biochemistry, blood gas, and physical examination

The magnificent frigatebird (Fregata magnificens; MFB) is a widely distributed seabird. It has breeding areas in the tropical Atlantic Ocean and the Pacific Ocean (extending along Central America up to Baja California) (Schreiber & Burger, 2001). The Fregata magnificens magnificens (MFB-Gal) subspecies is native to the Galápagos Islands. This is the first-time hematology and blood chemistry parameters have been published for the F. m. magnificens (MFB-Gal) from the Galápagos Islands. Analysis was run on blood samples drawn from n = 16 adult MFB-Gal captured by hand at their nests at North Seymour and Daphne Major Islands in the Galápagos Islands (n = 10 MFB-Gal in June 2017 and n = 6 MFB-Gal in July 2022). There were ten female birds and six male birds in total. A portable blood analyzer (iSTAT) was used to obtain near immediate field results for total carbon dioxide (TCO2), hematocrit (Hct), hemoglobin (Hb), sodium (Na), potassium (K), chloride (Cl), ionized calcium (iCa), total protein (TP), anion gap and glucose. Blood lactate was measured using a portable Lactate Plus™ analyzer. Average heart rate, respiratory rate, body weight, body temperature, biochemistry and hematology parameters were comparable to healthy individuals of other Fregatidae of the same species (magnificent frigatebird subspecies from Brazil, Fregata magnificens, likely F. m. rothschildi) or similar species (great frigatebird, Fregata minor, from the Galápagos Islands). There were some statistically significant differences between the males and females F. m. magnificens (MFB-Gal) in the Galápagos, including bill depth, bill width, wing length, weight, and chloride blood value. The reported results provide baseline data that can be used for comparisons among populations and in detecting changes in health status among Galápagos magnificent frigatebirds and other populations of magnificent frigatebirds.

Select Venous Analytes and Fibrinogen Determination Using Two Methods in Brown Pelicans

The brown pelican (Pelecanus occidentalis) is a species often affected by natural and man-made disasters such as hurricanes and oil spills, as well as general human activities; that subsequently receives medical care and rehabilitation. During rehabilitation, blood may be collected for various tests to help with diagnosis, treatment, and monitoring. Reference intervals for this species are limited, dated, and typically from small sample sizes. Seventy-one presumed healthy brown pelicans were sampled as part of their pre-release examination from rehabilitation at the Wildlife Center of Texas after a large volume stranding from December 2014 to January 2015, and various venous analytes were measured to establish updated reference intervals for brown pelicans. Fibrinogen was measured via heat precipitation and the Abaxis VSPro equine fibrinogen cartridge to determine reference intervals and in an attempt to validate the VSPro for use in avian species. Abaxis VS2 Avian/Reptile Chemistry panel, iSTAT CG4+, and iSTAT Chem8+ results, in addition to body condition score, spun PCV, cloacal temperature, and fibrinogen were measured. Proposed reference intervals for brown pelicans are presented. Fibrinogen results were not comparable between the gold standard method and the VSPro, indicating that the VSPro is not appropriate for use in brown pelicans.

Performance of a manually operated salad spinner centrifuge for serum separation in the healthy domestic horse (Equus caballus) and southern white rhinoceros (Ceratotherium simum)

BACKGROUND

Field veterinarians and researchers studying wild species, such as the southern white rhinoceros, often work in remote areas with limited access to standard laboratory equipment, hindering the ability to measure serum analytes.

OBJECTIVES

The first objective was to produce an inexpensive, manually operated centrifuge that could accept standard laboratory tubes by modifying a consumer-grade salad spinner with low-cost materials. The second objective was to compare biochemistry analysis results obtained from equine and southern white rhinoceros serum separated by traditional laboratory and manual salad spinner centrifugation.

METHODS

We optimized the design and serum separation protocol using non-anticoagulated equine blood. Equine and rhinoceros serum samples were separated by manual salad spinner or traditional laboratory centrifugation. Measured analytes included sodium, potassium, chloride, urea nitrogen, creatinine, phosphorous, total calcium, magnesium, glucose, total protein, albumin, globulin, creatinine kinase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, total bilirubin, bicarbonate, sorbitol dehydrogenase, and triglycerides. Results obtained from serum separated by each centrifugation technique were compared by Deming regression and Bland-Altman analyses.

RESULTS

A tube adaptor insert modeled after a swing angle rotor and a two-step salad spinner centrifugation yielded serum comparable to traditional laboratory centrifugation. For the majority of analytes, no proportional or constant biases were detected between centrifugation methods. A positive proportional bias in the measurement of ALP in serum separated by manual centrifugation was detected in both equine and rhinoceros samples.

CONCLUSIONS

Manual centrifugation with a modified salad spinner yields diagnostic quality serum suitable for the measurement of most standard biochemistry analytes.

Comparison of Hematocrit and Biochemical Analytes among Two Point-of-Care Analyzers (EPOC and i-STAT Alinity v) and a Veterinary Diagnostic Laboratory in the African Savanna Elephant (Loxodonta africana) and the Southern White Rhinoceros (Ceratotherium simum simum)

This study compared hematocrit measured with the EPOC and i-STAT Alinity v point-of-care analyzers and manual measurement of packed cell volume in managed African savanna elephants (Loxodonta africana) and southern white rhinoceros (Ceratotherium simum simum). Biochemical analytes were also measured with the EPOC, i-STAT Alinity v, and a veterinary diagnostic laboratory in the same animals. Analytes assessed included blood urea nitrogen, chloride, creatinine, glucose, ionized calcium, potassium, and sodium. There were no differences for hematocrit values for African savanna elephants or southern white rhinoceros (p ≤ 0.05). In African savanna elephants, there were no differences between the EPOC and i-STAT Alinity v analyzers for any measured analytes except ionized calcium. When compared to a veterinary diagnostic laboratory, there were differences for a majority of the biochemical analytes measured on the EPOC and i-STAT Alinity v analyzers in African savanna elephants. In southern white rhinoceros, there were differences for a majority of analytes among all three analyzers. While differences existed among the portable analyzers and a veterinary diagnostic laboratory for biochemical analytes in both species, these numerically small differences are unlikely to be clinically significant. For routine health care of African savanna elephants and southern white rhinoceros, these point-of-care analyzers may be a useful alternative to commercial analyzers for the parameters evaluated.

Revisiting glucose regulation in birds - A negative model of diabetes complications

Birds naturally have blood glucose concentrations that are nearly double levels measured for mammals of similar body size and studies have shown that birds are resistant to insulin-mediated glucose uptake into tissues. While a combination of high blood glucose and insulin resistance is associated with diabetes-related pathologies in mammals, birds do not develop such complications. Moreover, studies have shown that birds are resistant to oxidative stress and protein glycation and in fact, live longer than similar-sized mammals. This review seeks to explore how birds regulate blood glucose as well as various theories that might explain their apparent resistance to insulin-mediated glucose uptake and adaptations that enable them to thrive in a state of relative hyperglycemia.

Venous Blood Analytes and Osmolality of Rehabilitated Juvenile Black-bellied Whistling Ducks (Dendrocygna autumnalis)

Venous blood samples were collected from 129 apparently healthy, rehabilitated juvenile black-bellied whistling ducks (Dendrocygna autumnalis) immediately before release from rehabilitation. Blood gas, electrolyte, and select biochemical and hematologic values were analyzed by using a point-of-care analyzer, and complete blood cell counts and osmolality were determined. Most biochemical analyte values were distributed parametrically, while most hematologic values were nonparametrically distributed. Calculated osmolality values were in poor agreement with measured osmolality values, and values of packed cell volume had poor agreement with hematocrit values determined with the i-STAT 1. The physiologic values reported provide vital information to assess individual duck health and guide fluid therapy in captivity and may prove useful to assess free-living population health of this duck species.

Venous blood gas and chemistry components are moderately heritable in commercial white egg-laying hens under acute or chronic heat exposure

Heat stress has a large negative impact on poultry around the world in both intensive and small-scale production systems. Better understanding of genetic factors contributing to response to high ambient temperatures would provide a basis to develop strategies for alleviating negative impacts of heat on poultry production. The objective of this work was to characterize the genetic control (heritability estimate and quantitative trait loci (QTL)) of blood chemistry components before and after exposure to acute and chronic high ambient temperature in a commercial egg laying line Hy-Line W-36 female parent line mature hens were exposed to 4 wk of daily cyclic heat exposure. Blood was collected pre-heat, on the first day of heat, and 2 and 4 wk post heat initiation and analyzed immediately using an i-STAT® hand-held blood analyzer. Thirteen blood components were quantified at the 4 time points: pH, pCO2, pO2, HCO3, TCO2, sO2, iCa, Na, K, base excess, glucose, "hematocrit" (estimated from blood electrical conductivity, BEC), and "hemoglobin" (calculated from BEC). Heritabilities were estimated using genomic relationship information obtained from 600k SNP chip data. All 13 parameters exhibited a significant change after 5 h of heat exposure and most did not return to pre-heat levels throughout the duration of the study. Eight parameters (base excess, glucose, hemoglobin, HCO3, hematocrit, K, pCO2, TCO2) had heritability estimates differing from zero at one or more time points (0.21 to 0.45). The traits with significant heritability would be good candidates for use as biomarkers in a selection program if they are correlated with traits of economic importance that are more difficult to measure. QTL were identified for nine of the traits at one or more time point. These nine traits, however, did not have significant heritability estimates suggesting that while some QTL have been identified their effects are generally small.

HEALTH STATUS OF RED-FOOTED BOOBIES ( SULA SULA) DETERMINED BY HEMATOLOGY, BIOCHEMISTRY, BLOOD GASES, AND PHYSICAL EXAMINATION

The red-footed booby ( Sula sula) is a widely distributed sulid native to the Galápagos archipelago. Hematology and blood chemistry parameters have been published for this species, but not from the San Cristóbal rookery. Analyses were run on blood samples drawn from 31 manually restrained red-footed boobies that were captured by hand from their nests at Punta Pitt on San Cristóbal Island. A portable blood analyzer (iSTAT) was used to obtain near immediate field results for pH, partial pressure of oxygen, partial pressure of carbon dioxide, bicarbonate, hematocrit, hemoglobin, sodium, potassium, ionized calcium, and glucose. Blood lactate was measured using a portable Lactate Plus™ analyzer. Average heart rate, respiratory rate, body weight, body temperature, and biochemistry and hematology parameters were comparable to those of healthy individuals of other sulids. The reported results provide baseline data that can be used for comparisons among populations and in detecting changes in health status among Galápagos red-footed boobies.

Health Status of Great Frigatebirds (Fregata minor) Determined by Haematology, Biochemistry, Blood Gases, and Physical Examination

The great frigatebird, Fregata minor, is a widely distributed seabird native to the Galápagos archipelago. Haematology and blood chemistry parameters have been published for this species but not from the San Cristóbal and North Seymour great frigatebird breeding colonies. Analyses were run on blood samples drawn from 25 great frigatebirds captured by hand at their nests at Punta Pitt on San Cristóbal Island and 30 birds on North Seymour Island, Galápagos Islands. A portable blood analyser (iSTAT) was used to obtain near immediate field results for pH, pO₂, pCO₂, TCO₂, HCO_3^- , haematocrit (Hct), haemoglobin (Hb), sodium (Na), potassium (K), chloride (Cl), ionized calcium (iCa), creatinine, urea nitrogen, anion gap and glucose. Blood lactate was measured using a portable Lactate Plus™ analyser. Average heart rate, respiratory rate, body weight, body temperature, biochemistry and haematology parameters were comparable to healthy individuals of other Fregatidae. The reported results provide baseline data that can be used for comparisons among populations and in detecting changes in health status among Galápagos great frigatebirds.

Biochemistry and hematology parameters of the San Cristóbal Galápagos tortoise (Chelonoidis chathamensis)

As part of a planned introduction of captive Galapagos tortoises (Chelonoidis chathamensis) to the San Cristóbal highland farms, our veterinary team performed thorough physical examinations and health assessments of 32 tortoises. Blood samples were collected for packed cell volume (PCV), total solids (TS), white blood cell count (WBC) differential, estimated WBC and a biochemistry panel including lactate. In some cases not all of the values were obtainable but most of the tortoises have full complements of results. Despite a small number of minor abnormalities this was a healthy group of mixed age and sex tortoises that had been maintained with appropriate husbandry. This work establishes part of a scientific and technical database to provide qualitative and quantitative information when establishing sustainable development strategies aimed at the conservation of Galapagos tortoises.

Concentrations of calcium and 25-hydroxycholecalciferol (vitamin D3) in plasma of wild kākāpō (Strigops habroptilus) living on two islands in New Zealand

AIMS This preliminary study had the objectives of describing the concentrations of ionised calcium and 25-hydroxycholecalciferol (25(OH)D₃) in the blood of wild kākāpō (Strigops habroptilus) living on two islands in New Zealand, and to determine the effects of supplementary feeding on these blood parameters. METHODS Blood samples were obtained from 33 kākāpō living on two offshore islands during routine health checks in 2015. Birds on Hauturu were sampled in May (n=5) and birds on Whenua Hou were sampled in July (n=15) and November (n=26). Of the birds sampled on Whenua Hou in November, 15 received supplementary food prior to sampling. Samples were analysed for pH, and concentrations of ionised calcium, total calcium, phosphorous, total protein, albumin, globulin, uric acid and 25(OH)D₃. RESULTS Concentrations of ionised calcium did not differ between unsupplemented birds on the two islands, nor between supplemented (median 1.17 (95% CI=1.12-1.20) mmol/L) and unsupplemented (median 1.09 (95% CI=1.08-1.14) mmol/L) birds sampled in November on Whenua Hou (p>0.05), and were comparable with published normal ranges for other psittacines. Concentrations of 25(OH)D₃ did not differ between unsupplemented birds on the two islands (p>0.05), but were higher in supplemented (median 8.00 (95% CI=4.76-8.45) nmol/L) than unsupplemented (median 0.00 (95% CI=-0.16-0.48) nmol/L) birds on Whenua Hou (p<0.001). All values were much lower than published ranges for healthy psittacines. There was no difference between male and female birds on Whenua Hou for any parameter measured (p>0.05). CONCLUSIONS AND CLINICAL RELEVANCE The calcium status of the kākāpō in this study was comparable to other wild psittacines, however concentrations of 25(OH)D₃ were much lower. The concentrations of 25(OH)D₃ may be within the normal range for the species, however further data are required to confirm this. The significant increase in concentrations of 25(OH)D₃ in supplementary fed birds suggests that this food was providing more of the nutrient than the wild diet at that time of year, although the effects of this are unknown. Further investigation is required into the calcium and vitamin D₃ status of kākāpō, across a wider range of locations, seasons and ages. This would help define normal ranges for these parameters, allow interpretation in clinically abnormal individuals, and guide the refinement of supplementary foods. This information would, therefore, assist the future conservation management of this critically endangered species.

Blood gases, biochemistry and haematology of Galápagos hawksbill turtles (Eretmochelys imbricata)

The hawksbill turtle, Eretmochelys imbricata, is a marine chelonian with a circum-global distribution, but the species is critically endangered and has nearly vanished from the eastern Pacific. Although reference blood parameter intervals have been published for many chelonian species and populations, including nesting Atlantic hawksbills, no such baseline biochemical and blood gas values have been reported for wild Pacific hawksbill turtles. Blood samples were drawn from eight hawksbill turtles captured in near shore foraging locations within the Galápagos archipelago over a period of four sequential years; three of these turtles were recaptured and sampled on multiple occasions. Of the eight sea turtles sampled, five were immature and of unknown sex, and the other three were females. A portable blood analyzer was used to obtain near immediate field results for a suite of blood gas and chemistry parameters. Values affected by temperature were corrected in two ways: (i) with standard formulas and (ii) with auto-corrections made by the portable analyzer. A bench top blood chemistry analyzer was used to measure a series of biochemistry parameters from plasma. Standard laboratory haematology techniques were employed for red and white blood cell counts and to determine haematocrit manually, which was compared to the haematocrit values generated by the portable analyzer. The values reported in this study provide reference data that may be useful in comparisons among populations and in detecting changes in health status among Galápagos sea turtles. The findings might also be helpful in future efforts to demonstrate associations between specific biochemical parameters and disease or environmental disasters.

Point-of-care devices for physiological measurements in field conditions. A smorgasbord of instruments and validation procedures

Point-of-care (POC) devices provide quick diagnostic results that increase the efficiency of patient care. Many POC devices are currently available to measure metabolites, blood gases, hormones, disease biomarkers or pathogens in samples as diverse as blood, urine, feces or exhaled breath. This diversity is potentially very useful for the comparative physiologist in field studies if proper validation studies are carried out to justify the accuracy of the devices in non-human species under different conditions. Our review presents an account of physiological parameters that can be monitored with POC devices and surveys the literature for suitable quantitative and statistical procedures for comparing POC measurements with reference "gold standard" procedures. We provide a set of quantitative tools and report on different correlation coefficients (Lin's Concordance Correlation Coefficient or the more widespread Pearson correlation coefficient), describe the graphical assessment of variation using Bland-Altman plots and discuss the difference between Model I and Model II regression procedures. We also report on three validation datasets for lactate, glucose and hemoglobin measurements in birds using the newly proposed procedures. We conclude the review with a haphazard account of future developments in the field, emphasizing the interest in lab-on-a-chip devices to carry out more complex experimental measurements than the ones currently available in POC devices.

Commercial Hy-Line W-36 pullet and laying hen venous blood gas and chemistry profiles utilizing the portable i-STAT®1 analyzer

Venous blood gas and chemistry reference ranges were determined for commercial Hy-Line W-36 pullets and laying hens utilizing the portable i-STAT®1 analyzer and CG8+ cartridges. A total of 632 samples were analyzed from birds between 4 and 110 wk of age. Reference ranges were established for pullets (4 to 15 wk), first cycle laying hens (20 to 68 wk), and second cycle (post molt) laying hens (70 to 110 wk) for the following traits: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dl), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO₂ mm Hg), partial pressure oxygen (PO₂ mm Hg), total concentration carbon dioxide (TCO₂ mmol/L), bicarbonate (HCO₃ mmol/L), base excess (BE mmol/L), oxygen saturation (sO₂%), and hemoglobin (Hb g/dl). Data were analyzed using ANOVA to investigate the effect of production status as categorized by bird age. Trait relationships were evaluated by linear correlation and their spectral decomposition. All traits differed significantly among pullets and mature laying hens in both first and second lay cycles. Levels for K, iCa, Hct, pH, TCO₂, HCO₃, BE, sO₂, and Hb differed significantly between first cycle and second cycle laying hens. Many venous blood gas and chemistry parameters were significantly correlated. The first 3 eigenvalues explained ∼2/3 of total variation. The first 2 principal components (PC) explained 51% of the total variation and indicated acid-balance and relationship between blood O₂ and CO₂. The third PC explained 16% of variation and seems to be related to blood iCa. Establishing reference ranges for pullet and laying hen blood gas and chemistry with the i-STAT®1 handheld unit provides a mechanism to further investigate pullet and layer physiology, evaluate metabolic disturbances, and may potentially serve as a means to select breeder candidates with optimal blood gas or chemistry levels on-farm.