Laboratory blood analysis in Strigiformes-Part II: plasma biochemistry reference intervals and agreement between the Abaxis Vetscan V2 and the Roche Cobas c501

Markers of inflammation in free-living African elephants (Loxodonta africana): Reference intervals and diagnostic performance of acute phase reactants

INTRODUCTION

Acute phase reactants (APRs) have not been investigated in free-living African elephants (Loxodonta africana), and there is little information about negative APRs albumin and serum iron in elephants.

OBJECTIVES

We aimed to generate reference intervals (RIs) for APRs for free-living African elephants, and to determine the diagnostic performance of APRs in apparently healthy elephants and elephants with inflammatory lesions.

METHODS

Stored serum samples from 49 apparently healthy and 16 injured free-living elephants were used. The following APRs and methods were included: albumin, bromocresol green; haptoglobin, colorimetric assay; serum amyloid A (SAA), multispecies immunoturbidometric assay, and serum iron with ferrozine method. Reference intervals were generated using the nonparametric method. Indices of diagnostic accuracy were determined by receiver-operator characteristic (ROC) curve analysis.

RESULTS

Reference intervals were: albumin 41-55 g/L, haptoglobin 0.16-3.51 g/L, SAA < 10 mg/L, and serum iron 8.60-16.99 μmol/L. Serum iron and albumin concentrations were lower and haptoglobin and SAA concentrations were higher in the injured group. Serum iron had the best ability to predict health or inflammation, followed by haptoglobin, SAA, and albumin, with the area under the ROC curve ranging from 0.88-0.93.

CONCLUSIONS

SAA concentrations were lower in healthy African vs Asian elephants, and species-specific RIs should be used. Serum iron was determined to be a diagnostically useful negative APR which should be added to APR panels for elephants.

The Utility of Bile Acids for the Diagnosis of Liver Disease in Exotic Animals

The synthesis of bile acids occurs during the degradation of cholesterol in hepatocytes. Thus, this analyte is expected to be a sensitive indicator of hepatocellular dysfunction or alterations in portal circulation. Bile acids can be quantified via an enzymatic reaction to a highly conserved moiety across species. The evidence for the clinical utility of bile acids for the diagnosis of liver disease is strongest in birds and ferrets with equivocal evidence in rodents, rabbits, and reptiles. Current limitations to the interpretation of bile acids in exotic animal species include a paucity of species-specific reference intervals and incomplete understanding of bile acid metabolism in nonmammalian species and the diversity of bile acids synthesized by vertebrates.

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.

CLINICAL OBSERVATIONS OF BEE ENVENOMATION IN TOUCANS

There are numerous reports on envenomation, even fatal, secondary to bee attacks in humans and other mammals. In birds, reports on those incidents are scarce and there are none regarding honeybee (Apis mellifera) stings in toucans. In the first case presented, an adult female red-breasted toucan (Ramphastos dicolorus) received at least five bee stings in the periophthalmic area. Within 5 h the bird was lethargic and dehydrated. The urates were yellowish. Three days later the bird showed a moderate anemia, but no changes in the leukocyte count, beyond an elevated heterophil: lymphocyte ratio. Blood chemistry showed hyperglycemia, hypoalbuminemia and elevated aspartate aminotransferase and creatine kinase. Alterations in electrolyte values were also noted. Fourteen days later bile acid elevation was observed. Hematocrit levels normalized after 2 wk. A second incident involved a breeding pair of toco toucans (Ramphastos toco). While the female toco toucan received 10 stings and showed mild clinical manifestations, the male toco toucan was more severely attacked, receiving 40 stings, and died overnight. Despite the relative gravity of the attack (in terms of number of stingers in relation to body weight) both surviving birds recovered in less than 2 wk. To the authors' knowledge, fatal bee envenomation in birds has been reported only in pigeons and macaws. The findings described in this report suggest that toucans are less sensitive to bee venom when compared with pigeons and may have higher tolerance to bee venom compared with mammals. Honeybee envenomation must be considered a potential threat when considering toucan husbandry in zoos and collections.

Reference Intervals for Selected Hematology and Clinical Chemistry Measurands in Temminck's Pangolin (Smutsia temminckii)

Pangolins are the world's most trafficked non-human mammals. A significant number of Temminck's pangolins (Smutsia temminckii) are presented for veterinary care and rehabilitation in southern Africa. Little is known about the physiology and normal health of this species, making diagnosis and medical management difficult. This study aimed to establish reference intervals (RIs) for hematology and plasma clinical chemistry in the Temminck's pangolin. RIs were generated according to international guidelines using samples from 27 healthy free-living (n = 18) and rehabilitated (n = 9) pangolins. Hematology was performed using the Abaxis VetScan HM5 analyzer with manual differentials; clinical chemistry was performed using heparin plasma on the Abaxis VetScan VS2 and Cobas Integra 400 Plus analyzers. Hematology RIs were: RBC 3.88-8.31 × 10¹²/L, HGB 73-150 g/L, HCT 26-51%, MCV 59-72 fL, MCH 15.6-21.4 pg, MCHC 257-325 g/L, RDW 14.3-19.1%, WBC 1.80-10.71 × 10⁹/L. Vetscan VS2 clinical chemistry RIs were: albumin 27-41 g/L, ALP 26-100 U/L, ALT 25-307 U/L, amylase 267-826 U/L, bilirubin 4-10 μmol/L, calcium 2.1-2.2 mmol/L, globulin 21-55 g/L, glucose 3.8-10.0 mmol/L, phosphate 1.3-2.6 mmol/L, potassium 3.6-5.9 mmol/L, sodium 132-140 mmol/L total protein 52-84 g/L, and urea 5.3-11.4 mmol/L. RIs for creatinine were not calculated as analytical imprecision exceeded analytical performance goals. Cobas Integra clinical chemistry RIs were: albumin 22-33 g/L, ALP 20-104 U/L, ALT 17-291 U/L, amylase 466-1,533 U/L, bilirubin 1-14 μmol/L, calcium 2.0-2.4 mmol/L, creatinine <58 μmol/L, globulin 23-49 g/L, glucose 3.6-10.1 mmol/L, phosphate 1.0-2.2 mmol/L, potassium 3.1-5.8 mmol/L, sodium 137-150 mmol/L, total protein 47-72 g/L, and urea 6.0-12.5 mmol/L. There was significant bias between the two chemistry analyzers for several measurands. Differences were found for some analytes between free-living and rehabilitated animals, probably reflecting differences in nutrition and hydration. These are the first RIs generated for Temminck's pangolin. These results will allow veterinarians to better determine pangolin health status, formulate optimal treatment plans and increase patient survival rates in this endangered species.

PAIRED BIOCHEMICAL ANALYSIS OF PIGMENTED PLASMA SAMPLES FROM ZOO-KEPT AMERICAN FLAMINGOS (PHOENICOPTERUS RUBER) USING A POINT-OF-CARE AND A STANDARD WET CHEMISTRY ANALYZER

American flamingos (Phoenicopterus ruber) are commonly kept in zoological collections, making health monitoring essential. Use of point-of-care (POC) blood analyzers that require small volumes of whole blood samples produces prompt results allowing for rapid clinical decision-making. To evaluate and compare blood biochemistry analysis results analyzed by a POC biochemistry analyzer and a laboratory wet biochemistry analyzer, blood was collected from 17 apparently healthy zoo-kept American flamingos. Analyzer agreement was investigated using the Passing-Bablock regression analysis and Spearman correlation coefficients. Plasma samples from all birds were bright yellow in color. The results from the POC analyzer used in this study were found to be outside acceptance and clinical allowable error limits when compared with the laboratory analyzer for phosphorus (Phos), total protein (TP), albumin (Alb), glucose (Glu), creatine kinase (CK), and potassium (K). For aspartate aminotransferase (AST), results were within clinical allowable error but outside the acceptance limits, and for calcium (Ca) and sodium (Na), results were within both limits. The POC analyzer failed to measure the uric acid (UA) concentrations of all the samples, and reported all bile acids (BA) concentrations as below its minimal measurable limit. The use of analyzer-specific reference intervals is recommended for most analytes tested. The POC analyzer used in this study cannot be recommended for measuring UA concentrations in brightly colored samples from American flamingos.

CLINICAL CHEMISTRY, VITAMIN, ELECTROPHORESIS, AND HEMATOLOGIC ANALYTES OF BLACK-HEADED IBIS (THRESKIORNIS MELANOCEPHALUS)

The evaluation of laboratory blood analytes is an important tool for health assessment in avian medicine. Unfortunately, there is a lack of suitable reference values for many zoo bird species. The goal of the present study was to establish reference intervals for a wide range of blood analytes in healthy black-headed ibis (Threskiornis melanocephalus) kept in a zoologic garden. Lithium heparinized blood samples from 15 individuals were collected, and 18 different clinical chemistry analytes were measured. New are especially the minimum and maximum values for bile acid (2.38-49.4 µmol/L), cholinesterase (439-1260 U/L), vitamin A (0.65-1.70 mg/L), vitamin E (26.3-52.5 mg/L), and capillary zone electrophoresis (prealbumin, 10.2-23.4%; albumin, 35.9-44.1%; A/G ratio, 1.07-1.69; α-, 15.7-20.0%; β-, 13.5-19.1%; γ-globulin, 6.08-11.3%). The measured values for clinical chemistry, vitamin, electrophoresis, and hematologic analytes are a basis for further studies and for diagnostics and clinical treatment in this ibis species.

Comparison of portable and conventional laboratory analyzers for biochemical tests in chickens

Antemortem blood biochemical and blood gas analyses are routinely used in health screening and diagnosis of disease in domestic veterinary species. These testing modalities are not routinely performed in poultry, in part, due to the distance from the diagnostic laboratory. Portable blood analyzers such as the i-STAT and VetScan (VS2) can be used to obtain results on the farm without delay, potentially offering a more practical option for poultry practitioners. We investigated the time effect on blood chemistry values and compared the results obtained using the i-STAT and VS2 with those obtained using conventional laboratory analyzers (GEM Premier 3000 and Cobas c501, respectively). We tested blood from 60 healthy chickens. Each sample was tested in triplicate using each of the portable analyzers and once using conventional analyzers. All samples were analyzed within 60 minutes of collection. The concentrations of some analytes were outside the limit of detection of the portable analyzers (i.e., bile acids). Although statistically significant differences were found for some biochemical analytes over time, the actual mean or median differences were too small to be considered of clinical importance. As observed in mammals, significant time-dependent changes in blood gas analytes were observed in whole blood samples exposed to ambient air. Correlation coefficients between portable and conventional analyzers were moderate to high for most of the analytes. For the most part, there was an agreement between the portable and conventional analyzers. We identified constant and proportional biases in the measurement of multiple analytes by both the i-STAT and VS2. Future studies are warranted to establish analyzer-specific reference intervals for poultry.

A fatal case of a captive snowy owl (Bubo scandiacus) with Haemoproteus infection in Japan

Parasites of the genus Haemoproteus are vector-borne avian haemosporidia commonly found in bird species of the world. Haemoproteus infections are typically considered relatively benign in birds. However, some Haemoproteus species cause severe disease and mortality, especially for captive birds removed from their original habitat. In September 2018, a captive 15-year-old snowy owl (Bubo scandiacus), kept in a zoological garden of Japan, died subacutely after presenting leg dysfunction. This case showed significantly low PCV and elevated AST, ALT, CK, and LDH values. Many megalomeronts with prominent morphological characteristics of Haemoproteus were observed in the left leg muscles. Those megalomeronts exhibited multilocular structures and were internally filled with merozoites. A new lineage of Haemoproteus was detected by subsequent PCR for the cytochrome b (cytb) gene of avian haemosporidia from DNA extracted from several organ tissues. The detected lineage was classified in the subgenus Parahaemoproteus and was similar to those from the wild birds inhabiting the region including the study area, suggesting that this snowy owl likely acquired its infection from wild birds. This is the first report of a fatal case of a captive bird with a locally transmitted Haemoproteus infection in Japan. We considered the pathogenicity of this infection in conjunction with the clinical course and hematology results. We surmise that snowy owls may be particularly susceptible to infection with Haemoproteus parasites, and warming northern temperatures may exacerbate the overall health of these and other high latitude birds. Further research into the prevalence of Haemoproteus in wild birds near zoological gardens and potential biting midge vectors is necessary for the ex situ conservation of introduced birds.

Biochemical reference intervals for homing pigeons in China

As indicators of diseases, blood biochemical values play a crucial role in clinical practice and assessments of animals’ health condition. The rising population of homing pigeons in China has prompted needs for reliable blood biochemical reference intervals. Therefore, the aim of this study was to establish biochemical reference intervals for homing pigeons. Heparinized whole blood samples obtained from 77 clinically healthy pigeons were analyzed by Zoetis Abaxis VetScan VS2 with VetScan Avian/Reptilian Profile Plus Rotor. Reference intervals for pigeons were computed by Excel with Reference Value Advisor V2.1. The statistical analysis performed by SPSS program revealed correlations between biochemical analytes. Effects of sex and age and validity of published reference intervals were also discussed. The present results serve as a useful guide to broaden the scope of pigeon breeding industry.

Bilateral Anterior Uveitis in a Northern Saw-whet Owl (Aegolius acadicus) With a Metastatic Pectoral Malignant Mesenchymoma

A captive, adult, male northern saw-whet owl (Aegolius acadicus) was examined for blepharospasm of the left eye. The owl was diagnosed with bilateral anterior uveitis and a corneal ulceration in the left eye. It was treated with oral and topical nonsteroidal anti-inflammatory medications and a topical antibiotic. Multiple recheck examinations and medication adjustments were performed over the next 4 months, at the end of which time the bilateral anterior uveitis was controlled with a topical nonsteroidal anti-inflammatory applied 3 times per week to both eyes. The owl was re-examined 2 months later after 2 suspected neurologic episodes. On physical examination, the owl was quiet and had difficulty standing and ambulating. Five firm multilobular and immobile masses were identified overlying the pectoral muscle and sternum. Fine-needle aspiration from 1 mass revealed neoplastic cells consistent with a sarcoma. The owl was euthanatized. On the basis of results of histopathologic examination, the mass was diagnosed as a pleomorphic spindle cell sarcoma with features of rhabdomyosarcoma, liposarcoma, and osteosarcoma. Numerous tumor cells were immunopositive for myoglobin and desmin, indicating striated muscle origin. Although a metastatic lesion was present in 1 adrenal gland, lesions of inflammation or neoplasia were absent in either eye on histopathologic examination. This report describes an apparent ocular manifestation of systemic disease in an avian species with clinically diagnosed recurrent anterior uveitis.

Successful Management of Open, Contaminated Metacarpal Fractures in an Adult Snowy Owl ( Bubo scandiacus) With a Minimal Type II External Skeletal Fixator

An adult, male snowy owl ( Bubo scandiacus) was found down and unable to fly in western New York State. Physical examination and radiographs revealed a subacute, open wound and fractured major and minor metacarpals of the right wing. A minimal type II external skeletal fixator (ESF) device was placed on the right major metacarpal bone and the open wound was allowed to granulate and close. After evidence of bone union, the ESF device was removed. The owl performed auto-physiotherapy throughout the process and was released with sustained flight 2 months postoperatively. It was recaptured 7 weeks later and underwent further rehabilitation to allow successful release 11 months after surgical stabilization. To our knowledge, this is the first case report describing use of a type II ESF device on the metacarpus of a bird.

Reference Intervals for Plasma Biochemical Variables by Point-of-Care Testing in Captive Black-tailed Prairie Dogs (Cynomys ludovicianus)

Black-tailed prairie dogs (Cynomys ludovicianus) are kept in zoological collections, maintained as companion pets, and aretested in field and laboratory settings. Biochemical analysis for routine health and research purposes can be performed byusing point-of-care (POC) testing; however, analyzer- and species-specific reference intervals need to be determined. In this prospective study, 50 captive-raised sexually intact prairie dogs (16 females, 34 males) underwent plasma biochemical analysisby using a veterinary POC biochemical analyzer. We used a manufacturer-predetermined profile of 14 analytes: albumin, ALP,ALT, amylase, BUN, calcium, creatinine, glucose, potassium, sodium, phosphorus, total bilirubin, total protein and globulin.A subset of 17 samples was tested concurrently for the same 14 analytes by using a reference laboratory analyzer, and wedetermined RI for the POC analyzer for these 14 biochemical analytes. Sex had a significant effect on albumin and creatininevalues, which were higher in females than males, and on ALT, which was lower in females. In addition, age had an effect on9 plasma analytes: juvenile animals had higher plasma concentrations of albumin, ALP, ALT, BUN, and glucose than adultanimals, whereas adults had higher concentrations of creatinine, sodium, total protein, and globulins. Only calcium and BUNhad acceptable analytical agreement between the POC and reference analyzers. The reference intervals determined in this study can aid clinicians and researchers performing POC plasma biochemical analysis in prairie dogs, providing that they consider potential analyzer-, sex-, and age-related effects.

Plasma biochemistry RIs and age effect in European Strigiformes

BACKGROUND

Blood biochemistry and hematology are essential in the laboratory diagnosis of disease. In Strigiformes, little information regarding reference values and influence of different preanalytic factors is available, while age is known to have an effect on some biochemistry analytes, especially in early life characterized by a rapid growth rate and increase in body mass.

OBJECTIVE

The objective of this study was to determine baseline data for 29 blood biochemistry variables in 5 species of Iberian Strigiformes assigned to different age classes.

METHODS

Healthy nocturnal birds living in wildlife health centers of Catalonia, Northeastern Spain were assigned to different age classes (chicks, juveniles, adults where possible and available) and their blood was collected and analyzed for different standard biochemistry variables. Species included Tawny owls, Little owls, Long-eared owls, Scop owls, and Barn owls.

RESULTS

A total of 276 clinically healthy animals were sampled, including between 179 chicks, 52 juveniles, and 45 adults. The RIs of cholesterol, albumin, and osmolality were the only variables that did not show interspecific variability. Common trends between age class groups were observed in 4 species. Phosphorus and calcium concentrations and ALP activities decreased with increasing age, while concentrations of sodium and γ-globulins tended to increase in the Strigidae family. Differences were concentrated in chicks and no differences were observed between juveniles and adults in any variable.

CONCLUSIONS

Our results demonstrate the importance of defining biochemical RIs specific for certain age classes.

Hematologic and serum biochemical reference intervals of the Oriental white stork (Ciconia boyciana) and the application of an automatic hematologic analyzer

This study was conducted to establish accurate baseline values of clinical laboratory data with regard to age-related changes in the Oriental white stork (Ciconia boyciana). In addition, the availability of an automated hematological cell counter was evaluated. A total of 94 clinically normal storks, including 64 young storks (＜1 year old; 30 male and 34 female) and 30 adults (＞ 1 year old; 17 male and 13 female) were included. Hematological assays were performed using manual and automated cell counters and serum biochemistry profiles were examined using an automated analyzer. There were no significant differences in any parameters between male and female storks, while 16 parameters were significantly different between young and adult storks. Of these 16 parameters, total protein, albumin, aspartate aminotransferase, alanine aminotransferase, creatinine, triglyceride, total bilirubin, potassium, white blood cell count, packed cell volume, mean cell volume and hemoglobin levels were higher in adult storks than in young storks, while the latter showed higher glucose, uric acid and alkaline phosphatase levels, as well as a higher sodium/potassium ratio. The results presented herein will aid researchers who work for the conservation and rehabilitation of this endangered species.

Method comparison and generation of plasma biochemistry RIs for the White rhinoceros on a point-of-care and wet chemistry analyzer

BACKGROUND

Plasma biochemistry analysis may aid the management of White rhinoceros with poaching or other injuries. Analyzer- and species-specific RIs are necessary to evaluate health status and identify abnormalities.

OBJECTIVES

The purpose of the study was to perform a comparison study between the IDEXX VetTest and Roche Cobas Integra 400 Plus, and to generate analyzer-specific RIs for White rhinoceros according to published guidelines.

METHODS

Comparison was carried out using White rhinoceros plasma samples from healthy and diseased animals. Reference intervals for albumin, ALT, AST, CK, creatinine, GGT, globulins, glucose, phosphorus, total proteins, and urea were determined from a sample group of chemically immobilized healthy adult White rhinoceros from the Kruger National Park, South Africa.

RESULTS

There was a significant analytic bias for all analytes between the 2 analyzers. Results for glucose and total protein were clinically equivalent based on total allowable error limits. Reference intervals were generated from 51 individuals (26 male, 25 female) for all analytes except ALT on the VetTest.

DISCUSSION

The type, direction, and magnitude of bias between the VetTest and Cobas appeared to be species- and analyzer-specific, when compared to other studies. These measures of bias may be used for comparability testing. Reference intervals for total proteins (VetTest 77-108 g/L, Cobas 77-110 g/L) and globulins (VetTest 47-79 g/L, Cobas 51-87 g/L) were high compared to other uneven-toed ungulates.

CONCLUSION

Plasma samples from White rhinoceros can be evaluated on both the VetTest and Cobas. Results from this study will aid conservation efforts directed toward this species.

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.

EXPLORATORY PLASMA BIOCHEMISTRY REFERENCE INTERVALS FOR URAL OWLS (STRIX URALENSIS, PALLAS 1771) FROM THE AUSTRIAN REINTRODUCTION PROJECT

The Ural owl (Strix uralensis) is the biggest forest-living owl in Austria; however, it became extinct in Austria through poaching and habitat loss more than half a century ago. The birds examined in the present study were breeding pairs from the reintroduction project with the aim of determining exploratory plasma biochemistry reference intervals in Ural owls and evaluating the amount of biological variation between seasons, sexes, and ages. A total of 45 birds were sampled, including 13 adult males, 14 adult females, and 18 juvenile birds. Remarkably, almost all of the analytes showed significant differences between the subgroups, primarily between seasons, followed by age and sex. Only creatinkinase, glucose, lactatdehydrogenase, and triglycerides did not show any significant variations. Despite partitioning of reference values into subgroups according to biological variation diminishing the number of reference individuals in the respective groups, the resulting smaller reference intervals will improve medical assessment. The results of the present study once again demonstrate that significant seasonal fluctuations must be expected and considered in the interpretation. It can be assumed that these differences are probably even greater in free-range birds with considerable changes in food quantity and quality during and between years.

Laboratory blood analysis in Strigiformes-Part I: hematologic reference intervals and agreement between manual blood cell counting techniques

BACKGROUND

While hematologic reference intervals (RI) are available for multiple raptorial species of the order Accipitriformes and Falconiformes, there is a lack of valuable hematologic information in Strigiformes that can be used for diagnostic and health monitoring purposes.

OBJECTIVES

The objective was to report RI in Strigiformes for hematologic variables and to assess agreement between manual cell counting techniques.

METHODS

A multi-center prospective study was designed to assess hematologic RI and blood cell morphology in owl species. Samples were collected from individuals representing 13 Strigiformes species, including Great Horned Owl, Snowy Owl, Eurasian Eagle Owl, Barred Owl, Great Gray Owl, Ural Owl, Northern Saw-Whet Owls, Northern Hawk Owl, Spectacled Owl, Barn Owl, Eastern Screech Owl, Long-Eared Owl, and Short-Eared Owl. Red blood cell count was determined manually using a hemocytometer. White blood cell count was determined using 3 manual counting techniques: (1) phloxine B technique, (2) Natt and Herrick technique, and (3) estimation from the smear. Differential counts and blood cell morphology were determined on smears. Reference intervals were determined and agreement between methods was calculated.

RESULTS

Important species-specific differences were observed in blood cell counts and granulocyte morphology. Differences in WBC count between species did not appear to be predictable based on phylogenetic relationships. Overall, most boreal owl species exhibited a lower WBC count than other species. Important disagreements were found between different manual WBC counting techniques.

CONCLUSIONS

Disagreements observed between manual counting techniques suggest that technique-specific RI should be used in Strigiformes.

Laboratory blood analysis in Strigiformes-Part II: plasma biochemistry reference intervals and agreement between the Abaxis Vetscan V2 and the Roche Cobas c501

BACKGROUND

Limited plasma biochemical information is available in Strigiformes. Only one study investigated the agreement between a point-of-care with a reference laboratory analyzer for biochemistry variables in birds.

OBJECTIVES

The objective was to report reference intervals (RI) for plasma biochemistry variables in Strigiformes, and to assess agreement between the Abaxis Vetscan V2 and Roche Cobas c501.

METHODS

A prospective study was designed to assess plasma biochemistry RI for concentration of calcium, phosphorus, total protein, albumin, globulin, glucose, bilirubin, uric acid, bile acids, sodium, potassium, and chloride, and activities of AST, GGT, CK, amylase, lipase, LDH, and GLDH. In addition, the agreement between the Vetscan and the Cobas in owl species was assessed.

RESULTS

A total of 190 individuals were sampled belonging to 12 Strigiformes species including Barn Owls, Barred Owls, Great Horned Owls, Eurasian Eagle Owls, Spectacled Owls, Eastern Screech Owls, Long-Eared Owls, Short-Eared Owls, Great Gray Owls, Snowy Owls, Northern Saw-Whet Owls, and Northern Hawk-Owls. Order-, species-, and method-specific RI were determined on both analyzers. Although Vetscan data were not equivalent to the Cobas, 4 analytes (glucose, AST, CK, and total protein, with correction for bias) were within acceptable agreement, 3 analytes (uric acid, calcium, and phosphorus) were within close agreement, and the remaining analytes were in strong disagreement. Species-specific differences were observed notably for the concentration of glucose in Barn Owls and electrolytes in Northern Saw-Whet Owls.

CONCLUSIONS

Overall, this study suggests that the Vetscan has acceptable clinical performance in Strigiformes for some analytes and highlights discrepancies for several analytes.