Plasma biochemical reference intervals for koi

OBJECTIVE: To assess reproducibility of an in-house tabletop biochemical analyzer for measurement of plasma biochemical analytes and establish reference intervals in adult koi. DESIGN: Prospective study. ANIMALS: 71 healthy adult koi. PROCEDURES: Plasma was analyzed for concentrations or activities of albumin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, bile acids, BUN, calcium, cholesterol, creatine kinase, gamma-glutamyltransferase, globulin, glucose, K, Na, P, total bilirubin, total protein, and uric acid. Duplicate samples were evaluated by use of the intraclass correlation coefficient to determine reproducibility. To assess the magnitude of differences between replicate samples, the absolute mean difference, SD, and minimum and maximum values were calculated for each analyte. Median values and reference intervals were calculated. RESULTS: Intraclass correlation coefficient values were excellent for all analytes except alanine aminotransferase (good), Na (poor), gamma-glutamyltransferase (poor), and P (poor). Reference intervals were established. CONCLUSIONS AND CLINICAL RELEVANCE: The in-house tabletop biochemical analyzer had good precision for measuring most plasma biochemical analytes. Further research and comparison with other reference procedures are needed before reference intervals and precision can be established for globulin, Na, P, K, and albumin. Aquatic veterinarians may be able to use the reference intervals for adult koi as an important diagnostic tool or as part of a fish wellness program, as commonly done in other domestic species.     

Evaluation of an automated tabletop blood biochemical analyzer for the veterinary clinical pathology laboratory

The importance of accurate quantitative blood biochemical analysis for the diagnosis and management of disease is recognized by most veterinarians. In recent years, several biochemical analyzers have become available for the veterinary market. One of these analyzers was evaluated for its suitability in measuring several biochemical variables--alkaline phosphatase, urea nitrogen, creatinine, glucose, alanine transaminase (dog and cat only), and aspartate transaminase (horse only)--in dogs, cats, and horses. Instrument within-day precision ranged from 1.0 to 7.1%, and between-day precision ranged from 1.6 to 7.4%. During the 6-month period of the study, the analyzer required recalibration for only 1 analyte (creatinine). Concentrations of individual analytes were similar when blood (collected in anticoagulant), plasma, and serum were assayed in parallel. The accuracy of the analyzer, as measured by correlation to a reference method, ranged from 0.861 for creatinine in horses to greater than 0.950 for each of the other analytes in the 3 species. Mean values for each analyte were similar, except for alkaline phosphatase, which had consistently lower values by use of the analyzer method. A data base was established for reference values in each species.     

Haematological and biochemical findings in cats in Australia with lymphosarcoma

OBJECTIVE: To describe, for the first time, haematological and serum biochemical findings in cases of lymphosarcoma in Australian cats. DESIGN: A prospective multi-institutional study. PROCEDURE: Of 118 affected cats presented to the authors over a 18-month period, 97 were evaluated haematologically and 87 biochemically. Haematological analysis usually included determination of packed cell volume, haemoglobin concentration, red blood cell and leukocyte counts, differential leukcocyte count, reticulocyte count and examination of buffycoat smears for neoplastic cells. Serum biochemical analysis was done primarily with a discrete analyser and included a panel of commonly used analytes. RESULTS: Nonregenerative anaemia was present in 54% (52/97) of cats. Neutrophilia, present in 65% (59/91) of cats, was commonly associated with lymphocytopaenia, eosinopaenia and monocytosis. Of the 13 cats with a secondary leukaemic manifestation, only five had distinct lymphocytosis. Serum biochemical abnormalities either were nonspecific, such as hypoglycaemia in 37% (32/87) of cats, or related to specific tissue involvement, such as hypoalbuminaemia in 76% (31/41) of cats with alimentary involvement and azotaemia in 60% (15/25) of cats with renal involvement. CONCLUSION: It was shown for the first time that haematological and serum biochemical findings are of limited value in diagnosing lymphosarcoma in Australian cats, except if they are leukaemic. Although clinical pathological changes were common, they were nonspecific or related to specific tissue involvement. Their value in assessing response to therapy needs to be examined further. Patient characteristics such as age, breed and sex also had limited effect on laboratory findings and those observed were of little consequence. Additionally, histological and immunophenotypical variations in tumour type had little effect on laboratory findings.     

An automated spectrophotometric method for measuring canine ceruloplasmin in serum

An automated method for the determination of ceruloplasmin activity was developed and validated in canine serum. The method is based on the in vitro oxidase activity that this protein shows with substances such as p-phenylenediamine. In order to determine optimum assay conditions, the effects of the substrate concentration, buffer pH, reaction time and EDTA on the reaction were evaluated. The precision of the assay was good with within-run and between-run coefficients of variation lower than 10%. The method measured the ceruloplasmin values in a proportional and linear manner (r = 0.99) with a limit of detection of 0.0007 +/- 0.0001 Delta Abs/min. A temperature of -20 degrees C kept the reagent stable for 30 days. The method is cheap and easy to adapt to any automated biochemical analyser, considerably decreasing the processing time required with the manual method. Additionally it allows to differentiate dogs with pyometra and trauma from clinically healthy dogs.     

Breed‐associated variability in serum biochemical analytes in four large‐breed dogs

Background: Genetic background can influence the expected values of hematologic and serum biochemical analytes in domestic animal species. Objective: The purpose of this study was to determine if there are breed‐related differences in serum biochemical variables in healthy purebred dogs of 4 breeds and to develop appropriate reference intervals. Methods: Alaskan Malamutes (n=59), Siberian Huskies (n=78), Golden Retrievers (n=90), and English Setters (n=77) were included in the study. The dogs had a median age of 42 months (range 10–112 months) and each breed included a mix of intact and neutered dogs of both sexes. Serum biochemical profiles (Olympus AU400e) were performed along with physical examinations, CBCs, and urinalyses to ensure dogs were clinically healthy. Differences in the values of biochemical analytes were assessed nonparametrically and reference intervals for all breeds combined were calculated as the central 95% percentile. Results: Significant differences were observed between breeds for all serum biochemical analytes except alkaline phosphatase, glucose, and chloride. The analyte ranges had a large degree of overlap between the different breeds. Conclusions: Although many statistically significant breed‐related differences in serum biochemical values were observed, the differences were small and unlikely to have clinical relevance or impact medical decision making.     

Reference limits for biochemical and hematological analytes of dairy cows one week before and one week after parturition

Since dairy cows during the transition period have multiple endocrine and metabolic changes, it is necessary to determine the reference limits of laboratory analytes in normal transition cows. Reference limits for the weeks before and after calving were determined in dairy cows. Animals that had adverse clinical outcomes after calving and cows that were culled or had mastitis within the first 7 days after calving were excluded. All biochemical analytes (β-hydroxybutyrate, fatty acids, glucose, cholesterol, urea, calcium, and phosphorus) were statistically different between precalving and postcalving groups. The hematological analytes were not significantly different except for eosinophils. The data from precalving and postcalving cows were significantly different from reference limits in a university-associated laboratory derived from early- and mid-lactation cows. Different reference limits for precalving and postcalving dairy cows should be determined for biochemical analytes to ensure appropriate interpretation of results.     

Evaluation of biochemical analytes in vitreous humor collected after death in West Indian manatees

OBJECTIVE: To evaluate biochemical analytes in vitreous humor collected after death in West Indian manatees (Trichechus manatus latirostris). DESIGN: Prospective study. ANIMALS: 73 West Indian manatees of various ages and both sexes. PROCEDURE: The condition of manatee carcasses submitted for routine postmortem examination was categorized as fresh, moderately autolyzed, or severely autolyzed. The eyes were removed, frozen for shipping, and thawed on arrival at the laboratory. Vitreous humor was extracted, and various biochemical analytes were measured. Values for each analyte were compared with published reference ranges for corresponding biochemical analytes in serum. Values were also compared among the carcass condition groups. RESULTS: Creatinine and urea nitrogen concentrations in vitreous humor were significantly higher in severely autolyzed carcasses than in fresh carcasses. Potassium concentrations in vitreous humor were significantly higher in moderately autolyzed carcasses than in fresh carcasses but were highly variable in severely autolyzed carcasses. These data were consistent with those reported in other species. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that measurement of biochemical analytes in vitreous humor of manatees is feasible and has potential for assisting in the postmortem diagnosis of certain metabolic, renal, and nutritional diseases; determining severity of autolysis at time of necropsy; and determining the time of occurrence of human-induced trauma.     

Hemolysis as a factor in clinical chemistry and hematology of the dog

Serum biochemical, hemostatic, and hematologic analytes were determined by four laboratories on dog serum or plasmas containing increasing amounts of hemolysate. From the results of testing, interferographs were prepared to aid in decision making and to enhance visualization of the effects of hemolysis on the determination of the analytes. Heniktsus consistently interfered with the analysis of creatinine phosphokinase, lactic dehydrogenase, aspartate aminotransferase, lipase, and albumin, all of which appeared to increase with increasing hemolysis. The results for the remainder of the biochemical, hemostatic, and hematologic analytes varied greatly among analyzers or methods, rarely in a predictable manner, indicating that each laboratory should evaluate the effects of hemolysis on each analyzer and for each method used, in order to make informed decisions on the use of hemolyzed but irreplaceable samples.     

Comparison of measurements of 18 analytes in canine and feline blood samples using the in-practice Falcor 350 and the reference KoneLab 30i analysers

Objectives : Falcor 350 (A. Menarini Diagnostics) is a wet‐reagent biochemistry analyser that is available for in‐house use. The aim of this study was to compare the results produced by this analyser with those obtained by a wet‐reagent analyser (KoneLab 30i; Thermo Clinical Labsystems) that served as the reference instrument. Methods : Blood samples from 120 clinical cases (60 dogs and 60 cats) were analysed for 18 analytes (urea, creatinine, total proteins, albumin, creatine kinase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total bilirubin, amylase, lipase, glucose, triacylglycerol, cholesterol, total calcium, phosphate, sodium and potassium) using both the reference and Falcor instruments. Results : Good to excellent correlations (r_s value) (canine/feline) were identified for urea (0·87/0·86), creatinine (0·96/0·99), total proteins (0·91/0·95), albumin (0·96/0·93), creatine kinase (0·98/0·99), aspartate aminotransferase (0·95/0·98), alanine aminotransferase (0·99/0·99), alkaline phosphatase (0·99/0·98), total bilirubin in dogs (0·88), amylase (0·99/0·87), lipase in dogs (0·88), glucose (0·97/0·98), triacylglycerol (0·93/0·97), cholesterol (0·99/0·99), total calcium (0·88/0·89), phosphate (0·94/0·97) and potassium (0·96/0·97). The correlations for sodium (0·41/0·61), total bilirubin in cats (0·78) and lipase in cats (0·25) were considered unacceptable. Clinical Significance : For 13 of the 18 analytes (creatinine, total proteins, albumin, creatine kinase, aspartate aminotransferase, alanine aminotransferase, amylase, glucose, cholesterol, triacylglycerol, phosphate, potassium and urea) in both canine and feline samples, the two instruments produce values that are closely related to each other (excellent correlation) and are sufficiently similar to allow them to be used interchangeably without the need for additional correction factor computations (good agreement). Because of differences in the methodologies, the Falcor results for alkaline phosphatase, total calcium, sodium, lipase and total bilirubin cannot be used interchangeably with those generated by the KoneLab and should be interpreted using reference intervals established from the Falcor analyser.     

Age-related changes in hematology and plasma chemistry values of hybrid striped bass (Morone chrysops X Morone saxatilis)

Hybrid striped bass (Morone chrysops X Morone saxatilis ) are an important aquaculture species yet there are few diagnostic tools available to assess their health. Hematology and clinical chemistry analyses are not used extensively in fish medicine due to the lack of reference intervals for various fish species, and because factors such as age can affect blood values. There is little published information regarding age-related changes in blood values of juvenile fish. It is important to evaluate juvenile fish, as this is the time they are raised in aquaculture settings. Determining age-related changes in the blood values of fishes would further develop clinical pathology as a diagnostic tool, enhancing both fish medicine and the aquaculture industry. The results of standard hematology and clinical chemistry analysis were evaluated in juvenile hybrid striped bass at 4, 6, 9, 15, and 19 months of age. Values for PCV and RBC indices were significantly lower, and plasma protein concentration was significantly higher in younger fish. Total WBC and lymphocyte counts were significantly higher in fish at 6 and 9 months of age, while neutrophil and monocyte counts were higher at 6, 9, and 15 months. Eosinophil counts were significantly higher in 9-month-old fish. The majority of hematologic values fell within previously established reference intervals, indicating that only slight modification to the intervals is necessary for evaluating hematologic results of hybrid striped bass at different ages. The following analytes deviated sufficiently from adult reference intervals to warrant separate reference values: plasma protein concentration at 4 months, WBC and lymphocyte counts at 15 and 19 months, and thrombocyte-like-cells at 9 months of age. Values for most biochemical analytes were significantly different among age groups except for creatinine and potassium concentrations. Comparisons with reference intervals were not made for biochemical analytes, because established reference intervals were not available. Age-related changes in hematologic and biochemical values of striped bass were similar to those reported for rainbow trout and mammals.     

Stability of common biochemistry analytes in equine blood stored at room temperature

Reasons for performing study: Time delays between collection of blood samples and biochemical analysis of equine blood are unavoidably common in equine practice. The effect that delays may have on the accuracy of results of blood biochemical analyses is not well established. Hypothesis: Delays in processing of blood of up to 72h results in alterations in measured levels of common biochemical analytes that are of potential clinical relevance. Separation of serum prior to storage is protective against the effects of time delays. Methods: Samples of clotted blood, separated serum and oxalate fluoride plasma from 20 horses were stored and analysed at 0, 24, 48 and 72 h. Graphical exploration of each analyte was undertaken. General linear models with fixed effects were fitted for the whole blood data. The mean bias and 95% limits of agreement were calculated, using bootstrapped data, to assess agreement between pairs of samples analysed at 0 h and other time points. Bland‐Altman plots were used to explore general trends in the data. Paired t tests were used to compare the results from whole blood and separated serum. Results: Delays in processing equine blood resulted in significant increases in measured concentrations of aspartate aminotransferase, creatine kinase, lactate dehydrogenase, total bile acids and magnesium. A significant decrease in concentration was identified for glucose (serum and oxalate fluoride preserved plasma). Separation of serum immediately following clot formation resulted in nonsignificant increases in accuracy for some analytes. Conclusions and practical significance: Delays in processing of blood samples may result in biochemical changes of clinical relevance in individual cases; however, in the majority of cases, where delays are only a few days and a number of analytes are assessed concurrently, delays are unlikely to have an effect on the interpretation of results. Separation of serum following clot formation is of limited benefit. Clinical samples in which a delay in processing has occurred may be interpreted with reference to the data presented.     

Analysis of canine and feline blood samples using the Kuadro in-house wet-reagent chemistry analyser

OBJECTIVES: Kuadro is a new wet-reagent biochemistry analyser that is available for in-house use. The aim of this study was to compare the results produced by this analyser with those obtained by a wet-reagent analyser (KoneLab 30i) that served as the reference instrument. METHODS: Blood samples from 80 clinical cases (40 dogs and 40 cats) were analysed for urea, creatinine, total proteins, albumin, glucose, cholesterol, alanine aminotransferase, alkaline phosphatase, total bilirubin, amylase, total calcium, and phosphate using both the reference and Kuadro instruments. RESULTS: Kuadro performed very well on canine and feline samples, showing clinically acceptable correlations (r value) (canine/feline) for urea (0.99/0.97), creatinine (0.99/0.98), total proteins (0.95/0.97), albumin (0.98/0.90), glucose (0.99/0.99), cholesterol (0.99/0.99), alanine aminotransferase (1.00/0.99), alkaline phosphatase (0.96/0.99), total bilirubin (1.00/1.00), amylase (0.98/0.96), and phosphate (0.91/0.92). The correlation for total calcium measurements was clinically unacceptable (0.78/0.83). CLINICAL SIGNIFICANCE: Urea, creatinine, albumin, glucose, cholesterol, alanine aminotransferase, and phosphate Kuadro values can be used interchangeably with those generated by the reference analyser. Alkaline phosphatase, amylase, and total proteins Kuadro values cannot be used interchangeably, as Kuadro overestimated alkaline phosphatase and amylase and underestimated total protein measurements. Kuadro significantly underestimated total calcium concentrations due to the shorter incubation time used by the Kuadro analyser compared with the incubation time used in the reference analyser assay system.     

Application of the Vettest 8008 system for the biochemical analysis of vervet monkey plasma

A clinical biochemistry analyser designed specifically for veterinary use was used to analyse plasma samples from 24 vervet monkeys (Cercopithecus aethiops). Two millilitres of heparinised blood was collected from each of the 24 monkeys on four occasions at intervals of one week. Plasma was separated and analysed for the concentrations of triglycerides, cholesterol, total proteins, albumin, globulins, creatinine and blood urea nitrogen (BUN) and the activities of alkaline phosphatase (AP), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and creatine kinase (CK). The tests were easy to perform, used small volumes of plasma, and yielded consistent results for most of the analytes. The activities of CK and AP, but not AST, appeared to be influenced by haemolysis, and there were significant individual variations in the activity of LDH.     

Haematology, blood chemistry and urine parameters of free-ranging plains viscachas (Lagostomus maximus) in Argentina determined by use of a portable blood analyser (i-STAT) and conventional laboratory methods

Haematology, blood chemistry and urine values were determined for 44 adult free-ranging plains viscachas (Lagostomus maximus; Rodentia, Chinchillidae) in their pampas habitat in central Argentina. The study animals were captured in the wild and anaesthetized with a ketamine-xylazine combination for physical examination and sampling. Blood was obtained by venipuncture of the saphenous vein. Results for many of the blood parameters fall within the reference ranges for pet chinchillas. Differentiation of white blood cells revealed a predominantly neutrophil count for plains viscachas, while chinchillas have predominantly lymphocytes. Mean values for blood urea nitrogen, creatinine, aspartate aminotransferase and sodium were higher than the upper limit of the reference range for pet chinchillas. The results of seven analytes (haematocrit, haemoglobin, glucose, blood urea nitrogen, sodium, potassium, chloride) were compared by using both a portable blood analyser (i-STAT) in the field and conventional laboratory methods. In general, correlation and agreement between the two methods were low for most parameters.     

Differences between Plasma and Serum Samples for the Evaluation of Blood Chemistry Values in Rainbow Trout,Channel Catfish,Hybrid Tilapias,and Hybrid Striped Bass

Abstract

Blood chemistry analytes are determined for fish from either serum or plasma samples. Serum and plasma are similar in that they both represent the fluid component of blood; however, plasma contains clotting factors that are not present in serum. This study was conducted to determine whether the type of sample—plasma or serum—had an effect on measured blood analytes in rainbow trout Oncorhynchus mykiss, channel catfish Ictalurus punctatus, hybrid tilapia Oreochromis spp., and hybrid striped bass (striped bass Morone saxatilis × white bass M. chrysops). Paired plasma and serum samples were analyzed for the following standard biochemical analytes: total protein, albumin, globulin, creatinine, total bilirubin, alkaline phosphatase, aspartate aminotransferase, sodium, potassium, chloride, calcium magnesium, phosphorus, glucose, and cholesterol. For all four taxa, values for potassium were lower in the serum and magnesium and phosphorus values were higher in the serum. Glucose values were lower in the serum from rainbow trout, hybrid striped bass, and channel catfish; whereas cholesterol values were higher in the serum of rainbow trout, channel catfish, and hybrid tilapias. The differences observed between serum and plasma were distinct from changes occurring with hemolysis and, therefore, do not represent release of erythrocyte constituents. The differences most likely represent metabolic utilization of blood constituents while the blood was clotting. This work indicates that plasma should be used preferentially to serum for biochemical analysis because analyte levels determined from serum may not accurately reflect those found in circulating blood.     

The accuracy of the Lactate Pro hand-held analyser to determine blood lactate in healthy dogs

OBJECTIVES: The objective of this study was to determine the accuracy of the Lactate Pro hand-held analyser in measuring blood lactate levels. METHODS: Blood was drawn from 15 healthy dogs into five tubes containing Na-EDTA. Lactate was measured immediately using the Lactate Pro analyser and a laboratory reference method. Further samples were analysed 120, 240, 480 and 1440 minutes later to artificially increase the lactate levels. Lactate was measured in blood samples of 60 healthy dogs using the Lactate Pro analyser to determine the reference interval of lactate concentration in normal dogs. RESULTS: The correlation between the lactate concentration measured with the Lactate Pro analyser and the reference method was high. Lactate levels were lower when measured with the hand-held analyser than with the traditional laboratory determination. The reference interval for blood lactate concentrations in healthy dogs established by the Lactate Pro analyser was from the detection limit (0.8 mmol/l) up to 3.3 mmol/l. CLINICAL SIGNIFICANCE: The Lactate Pro analyser provides quick and reliable measurements of blood lactate in dogs with blood lactate levels up to 10 mmol/l. Because of its small sample size, this analyser will be particularly appropriate for use in small animal intensive care.     

Age-specific plasma biochemistry reference ranges in <1 year old dogs in Japan

The purpose of this study was to investigate and propose possible reference intervals of plasma biochemical analytes in young dogs (<12 months old) in Japan, using 896 canine plasma samples, collected from an array of veterinary clinics throughout the greater Tokyo metropolis area in Japan. The following biochemical parameters were assessed: albumin (ALB), alanine aminotransferase (ALT), alkaline phosphatase (ALP), amylase, aspartate aminotransferase (AST), blood urea nitrogen (BUN), creatinine (CRE), glucose, lipase, total cholesterol (T-Cho), and total protein (TP) were evaluated. Multivariate linear regression analysis indicated that partitioning according to age or gender may be necessary for some plasma analytes. Age appeared to significantly affect ALB, ALT, ALP, BUN, Glucose, Lipase, and Total Protein (P=?<0.001, <0.001, <0.001, 0.013, <0.001, 0.025, and <0.001, respectively). On the other hand, gender significantly influenced ALP, Amylase, Lipase, and T-Cho levels (P=0.017, <0.001, <0.001, and <0.001, respectively) whereas it may be borderline significant with ALT (P=0.072).     

氨基色谱柱测定蜂蜜中4种糖方法研究

《中国药典》(2015年)蜂蜜中规定:用Prevail Carbohyrate ES色谱柱,以乙腈-水(75:25)为流动相,示差折光检测器测定蜂蜜中的果糖、葡萄糖、蔗糖及麦芽糖。此次试验证明用普通氨基色谱柱替代Prevail Carbohyrate ES色谱柱,待测组分与其他组分分离良好,精密度试验满足要求,回收率试验结果大于93%,结果准确、可靠,普通氨基柱可替代Prevail Carbohyrate ES色谱柱,用于蜂蜜中糖类物质的测定。     

Reference ranges for biochemical and haematological values in farmed saltwater crocodile (Crocodylus porosus) yearlings

Objective To determine reference ranges for healthy yearling farmed saltwater crocodiles by performing routine biochemical and haematological laboratory tests on blood samples.
Design A clinico-pathological study.
Procedure Blood samples were collected from 120 healthy yearlings from four Northern Territory crocodile farms and body weight and length were measured. All animals had been fasted for 2 days before sample collection. Routine biochemical analytes were determined on 120 samples and haematological values determined on 30 samples (from one farm).
Results Reference ranges for biochemical and haemato-logical values were determined for farmed yearling saltwater crocodiles in the Northern Territory.
Conclusion The results were comparable with published reference ranges for other crocodilian species. Other published results of haematological values from saltwater crocodiles were from very young (6-week-old) hatchlings and older (2- to 4-year-old) crocodiles. Differences in values were presumed to be caused by age-related factors.     

Assessment of pulse co-oximetry technology after in vivo adjustment in anaesthetized dogs

ObjectiveTo compare values of haemoglobin concentration (SpHb), arterial haemoglobin saturation (SpO₂) and calculated arterial oxygen content (SpOC), measured noninvasively with a pulse co-oximeter before and after in vivo adjustment (via calibration of the device using a measured haemoglobin concentration) with those measured invasively using a spectrophotometric-based blood gas analyser in anaesthetized dogs.Study designProspective observational clinical study.AnimalsA group of 39 adult dogs.MethodsIn all dogs after standard instrumentation, the dorsal metatarsal artery was catheterised for blood sampling, and a pulse co-oximeter probe was applied to the tongue for noninvasive measurements. Paired data for SpHb, SpO₂ and SpOC from the pulse co-oximeter and haemoglobin arterial oxygen saturation (SaO₂) and arterial oxygen content (CaO₂) from the blood gas analyser were obtained before and after in vivo adjustment. Bland–Altman analysis for repeated measurements was used to evaluate the bias, precision and agreement between the pulse co-oximeter and the blood gas analyser. Data are presented as mean differences and 95% limits of agreement (LoA).ResultsA total of 39 data pairs were obtained before in vivo adjustment. The mean invasively measured haemoglobin–SpHb difference was –2.7 g dL^?1 with LoA of –4.9 to –0.5 g dL^?1. After in vivo adjustment, 104 data pairs were obtained. The mean invasively measured haemoglobin–SpHb difference was –0.2 g dL^?1 with LoA of –1.1 to 0.6 g dL^?1. The mean SaO₂–SpO₂ difference was 0.86% with LoA of –0.8% to 2.5% and that between CaO₂–SpOC was 0.66 mL dL^–1 with LoA of –2.59 to 3.91 mL dL^–1.ConclusionsBefore in vivo adjustment, pulse co-oximeter derived values overestimated the spectrophotometric-based blood gas analyser haemoglobin and CaO₂ values. After in vivo adjustment, the accuracy, precision and LoA markedly improved. Therefore, in vivo adjustment is recommended when using this device to monitor SpHb in anaesthetised dogs.