Measurement of serum C-reactive protein concentration for discriminating between suppurative arthritis and osteoarthritis in dogs.

BACKGROUND: In a dog with joint pain, it is important to determine whether it has suppurative joint disease, characterized by exudation of neutrophils in the synovial fluid, or not, as this affects choice of diagnostic tests and treatments. The aim of this study was to evaluate whether measurement of serum C-reactive protein (CRP) concentration could be used to discriminate between dogs with suppurative arthritis and osteoarthritis (OA). Furthermore, the concentrations of serum and synovial fluid interleukin (IL) 6 concentrations were measured in dogs with joint disease and in healthy dogs, and were correlated to serum CRP concentrations. METHODS: Dogs with joint pain were enrolled prospectively and were classified to have suppurative arthritis or OA based on synovial fluid analysis and radiographic/arthroscopic findings. Healthy Beagles were enrolled as a comparative group. CRP and IL-6 concentrations were measured with canine-specific immunoassays. The performance of CRP concentration in discriminating between dogs with suppurative arthritis and OA was evaluated using a previously established clinical decision limit for CRP (20 mg/l), and by receiver operator characteristic (ROC) curve and logistic regression analysis. Comparisons of CRP and IL-6 concentrations between groups were performed using t-tests, and correlations by Spearman rank correlation coefficients. RESULTS: Samples were obtained from 31 dogs with suppurative arthritis, 34 dogs with OA, and 17 healthy dogs. Sixty-two out of 65 dogs with joint disease were correctly classified using the clinical decision limit for CRP. Evaluation of ROC curve and regression analysis indicated that serum CRP concentrations could discriminate between suppurative arthritis and OA. Dogs with suppurative arthritis had higher serum CRP and serum and synovial fluid IL-6 concentrations compared to dogs with OA (p < 0.001). Dogs with OA had higher synovial fluid IL-6 concentrations (p < 0.001), but not higher serum CRP (p = 0.29) or serum IL-6 (p = 0.07) concentrations, compared to healthy dogs. There was a positive correlation between synovial fluid IL-6 and serum CRP concentrations (rs = 0.733, p < 0.001), and between serum IL-6 and serum CRP concentrations (rs = 0.729, p < 0.001). CONCLUSION: CRP concentration was found to discriminate well between dogs with suppurative arthritis and OA.

The effect of a single dose of prednisolone in dogs envenomated by Vipera berus--a randomized, double-blind, placebo-controlled clinical trial.

BACKGROUND: Treatment with glucocorticoids after snakebite in dogs is controversial and randomized clinical studies are missing. The objective of this study was to investigate the effect of a single dose of prednisolone in dogs envenomated by Vipera berus in a double-blind placebo-controlled study, after exclusion of dogs treated with antivenom. The two treatment groups were compared regarding clinical status and clinicopathological test results. A total of 75 dogs bitten by Vipera berus within the previous 24 hours were included. Clinical assessment, blood sampling and measurement of the bitten body part were done at admission (Day 1), after 24 hours (Day 2) and at a re-examination (Re-exam) after 10-28 days. Dogs were given prednisolone 1 mg/kg bodyweight (PRED) or saline (PLACEBO) subcutaneously in a randomized, double-blind clinical trial. Dogs were examined clinically and mental status and extent of edema were described. Furthermore, appetite, vomiting, diarrhea, cardiac arrhythmia and death were recorded. Concentrations of C-reactive protein (CRP) and high sensitivity cardiac Troponin I (cTnI), hematology variables and Prothrombin time (PT) were determined. Systemic inflammation was defined as present if CRP > 35 mg/l. RESULTS: None of the dogs died during the study period. The mental status was reduced in 60/75 (80%) of dogs on Day 1, compared to 19/75 (25%) on Day 2. The proportion of dogs with no or only mild edema increased significantly from Day 1 to Day 2. About one-third of the dogs developed gastrointestinal signs during the study period. Cardiac arrhythmia was uncommon. Clinicopathological changes included increased total leucocyte count, CRP and troponin concentration on Day 2. The cTnI concentration was increased in dogs with systemic inflammation, compared to dogs without systemic inflammation. A single dose of prednisolone did not significantly affect any of the clinical or clinicopathological parameters studied, except for a higher monocyte count on Day 2 in dogs that had received prednisolone treatment. CONCLUSION: The results of the present study do not support routine administration of a single dose of prednisolone 1 mg/kg subcutaneously in dogs bitten by Vipera berus.

The Diagnostic Value of Serum Amyloid A and Other Laboratory and Clinical Variables in Cats with Increased Liver Enzyme Activity.

Distinguishing inflammatory from non-inflammatory liver disease in cats may impact management. The study aim was to evaluate if certain diagnostic variables, including Serum Amyloid A (SAA), differ (1) between various clinical disease categories (Primary liver disease, Extrahepatic, Trauma and Inconclusive) and (2) between cytological findings of severe hepatic lipidosis and other cytological findings in cats with increased liver enzymes. Medical records from 5042 cats, where SAA had been measured, were reviewed, and 566 cats fulfilled inclusion criteria consisting of increased liver enzymes and available biochemical panel results. SAA was higher in cats diagnosed with trauma compared to other diseases (p = 0.008). Cytology results were available in 85 cats, and cats with severe lipidosis had lower serum SAA concentration (p < 0.0001) and were younger (p < 0.0002) compared to cats with other cytological findings. The study shows that SAA was higher in cats diagnosed with trauma compared to cats with other causes of increased liver enzymes and that SAA may be useful to distinguish cats with cytologic evidence of hepatic lipidosis from cats with other liver pathologies. Serum Amyloid A may be a valuable complement to liver cytology when investigating cats with increased liver enzymes.

Feline Heinz bodies interfering in standard bicarbonate analysis by the ABL90 FLEX.

Venous blood gases were analyzed with ABL90 FLEX in two cats with Heinz bodies in approximately 60% of the erythrocytes. The instrument demonstrated an inability to correctly report standard bicarbonate (stHCO3 - ), hematocrits, and hemoglobin concentrations by indicating an OXI spectrum mismatch alarm (ie, the spectrum of measured hemoglobin forms differed from the spectrum of calculated forms). Actual bicarbonate (aHCO3 - ) did not indicate any errors. The ABL90 FLEX uses spectrophotometry to measure hemoglobin, and the presence of Heinz bodies interfered with the measurement in these cases. Because hemoglobin is included in the formula for calculating stHCO3 - , the instrument gave an alarm for stHCO3 - . At follow-up, Heinz bodies were present in only 2%-3% of the erythrocytes, and the ABL90 FLEX did not indicate any alarm messages. To the authors' knowledge, these are the first cases reported that have interference in stHCO3 - measurements due to Heinz body formation using the ABL90 FLEX, a common blood gas instrument used in both veterinary and human critical care. The methodology used for evaluating acid-base status should be taken into consideration, and caution is needed when interpreting acid-base results in cats with Heinz bodies.

Partial validation of the Vcheck canine pancreatic lipase assay.

Measurement of canine pancreatic lipase immunoreactivity (cPLI) is used for diagnosing pancreatitis in dogs. Because pancreatitis can be a life-threatening disease with severe complications, an in-house cPLI test would be valuable to obtain rapid test results. The aim of this study was to evaluate a point-of-care cPLI test, Vcheck cPL. Precision, determined according to EP15, and linearity under dilution were determined and judged against preset quality goals. Results from the Vcheck cPL were compared with a previously validated cPLI ELISA, Spec cPL. In a retrospective study, cPLI results from dogs with and without acute pancreatitis, as determined by pancreatic ultrasound examination, were investigated to assess the performance of the assay in a clinical setting. Statistical analysis included the Mann-Whitney test, Chi-square test, and Passing-Bablok regression analysis with a significance level of 0.05. Precision of the assay was acceptable, with intra-, inter-, and total coefficients of variation (CV%) less than 12.1%, 6.4%, and 12.1%, respectively. Results from the linearity study indicated that the method was acceptably linear at lower concentrations but not in the high-concentration range. The method comparison study revealed that Vcheck generally measured higher concentrations compared with Spec cPL, and that the methods should not be used interchangeably. Dogs with acute pancreatitis had significantly higher cPLI concentrations compared with dogs without pancreatitis (P < 0.01), but there was a marked overlap in cPL concentrations between the two groups.

Hereditary phosphofructokinase deficiency in wachtelhunds.

Hereditary phosphofructokinase (PFK) deficiency was diagnosed in two Wachtelhund dogs and suspected in three related Wachtelhund dogs with exercise intolerance, hemolytic anemia, and pigmenturia. Severe, persistent reticulocytosis in light of only mild anemia together with hemoglobinuria after strenuous exercise suggested PFK deficiency. Low erythrocyte PFK activity together with low 2,3-diphosphoglycerate concentrations and a high hemoglobin-oxygen affinity confirmed the diagnosis. The PFK deficiency is due to a single missense mutation in the muscle-type PFK M-PFK gene in English springer and American cocker spaniels, whippets, and mixed-breed dogs; however, these PFK-deficient Wachtelhunds do not have the same PFK mutation.

Inflammatory changes during canine pregnancy.

Pregnancy is considered a pro-inflammatory state that requires physiologic adaptation of the immune system of the mother. The aim of the present study was to study inflammatory and hormonal changes during canine pregnancy. Studies included analyses of peripheral concentrations of the acute phase proteins fibrinogen and C-reactive protein (CRP), the hormones progesterone and insulin-like growth factor I (IGF-I), hemoglobin, and analyses of the total leukocyte numbers and expression of cell surface antigens. Twenty bitches were included in the present study; 12 pregnant bitches and eight non-pregnant control bitches that were followed during the corresponding phase of the oestrous cycle. Blood samples were collected at the day of optimal mating (day 0) and then on days 7, 14, 21, 28 and 42. Progesterone, IGF-I and CRP were analysed in serum and fibrinogen in EDTA plasma. Haematology and leukocyte expression of a panel of inflammation-associated adhesion molecules (CD 11a, CD 18 and CD 49d) were evaluated from EDTA blood. The data were analyzed as repeated-measures data, using a mixed model approach. Progesterone varied with time in both pregnant and control bitches, and IGF-I varied with time in pregnant bitches. Both fibrinogen and CRP increased significantly with time for the pregnant bitches, but no significant change was detected for the control bitches. Increases were seen from day 21. The hemoglobin concentration decreased significantly with time in both pregnant and non-pregnant bitches. The neutrophil and monocyte numbers increased significantly in pregnant but not in control bitches. Pregnancy induced increased granulocyte expression of cell surface marker CD 18, increased monocyte expression of CD 18 and CD 49d, and increased lymphocyte expression of CD 49d. In conclusion, we describe inflammatory changes during canine pregnancy that are manifested as increases in concentrations of CRP and fibrinogen, an increase in neutrophils and monocytes, and in activation of granulocytes, monocytes and lymphocytes. The changes should be taken into account when evaluating concentrations of APPs and WBC in bitches during pregnancy. A variation in IGF-I concentrations was detected during pregnancy.

Plateletcrit is superior to platelet count for assessing platelet status in Cavalier King Charles Spaniels.

BACKGROUND: Many Cavalier King Charles Spaniel (CKCS) dogs are affected by an autosomal recessive dysplasia of platelets resulting in fewer but larger platelets. The IDEXX Vet Autoread (QBC) hematology analyzer directly measures the relative volume of platelets in a blood sample (plateletcrit). We hypothesized that CKCS both with and without hereditary macrothrombocytosis would have a normal plateletcrit and that the QBC results would better identify the total circulating volume of platelets in CKSC than methods directly enumerating platelet numbers. OBJECTIVES: The major purpose of this study was to compare the QBC platelet results with platelet counts from other automated and manual methods for evaluating platelet status in CKCS dogs. METHODS: Platelet counts were determined in fresh EDTA blood from 27 adult CKCS dogs using the QBC, Sysmex XT-2000iV (optical and impedance), CELL-DYN 3500, blood smear estimate, and manual methods. Sysmex optical platelet counts were reanalyzed following gating to determine the number and percentage of normal- and large-sized platelets in each blood sample. RESULTS: None of the 27 CKCS dogs had thrombocytopenia (defined as <164 x 10(9) platelets/L) based on the QBC platelet count. Fourteen (52%) to 18 (66%) of the dogs had thrombocytopenia with other methods. The percentage of large platelets, as determined by regating the Sysmex optical platelet counts, ranged from 1% to 75%, in a gradual continuum. CONCLUSIONS: The QBC may be the best analyzer for assessing clinically relevant thrombocytopenia in CKCS dogs, because its platelet count is based on the plateletcrit, a measurement of platelet mass.

Serum C-reactive protein concentrations in Nova Scotia Duck Tolling Retrievers with immune-mediated rheumatic disease.

Nova Scotia Duck Tolling Retrievers (NSDTRs) are a dog breed often affected by immune-mediated rheumatic disease (IMRD), a disorder characterised by chronic stiffness and joint pain. Most, but not all, dogs with IMRD, have antinuclear antibodies (ANA), which are also commonly present in the autoimmune disease systemic lupus erythematosus (SLE). The clinical and diagnostic findings of IMRD indicate that it is an SLE-related disorder. C-reactive protein (CRP), an acute phase protein, is a quantitative marker of inflammation for many diseases and is used for diagnosing and monitoring systemic inflammation in both humans and dogs. However, in human SLE, CRP concentrations are often elevated but correlate poorly with disease activity; they can be low in individual patients with active disease. The aim of the study was to investigate CRP in a group of NSDTRs with the SLE-related disorder IMRD. The hypothesis was that CRP concentrations would be increased in dogs with IMRD compared to healthy dogs, but that the increase would be mild. Serum CRP concentrations were measured in 18 IMRD-affected NSDTRs and 19 healthy control NSDTRs using two different canine-specific CRP assays. Dogs with IMRD and ANA had higher CRP concentrations than the control dogs, but the concentrations were below the clinical decision limit for systemic inflammation for most of the IMRD dogs. These results indicate that CRP concentrations were increased in dogs with IMRD and ANA, but the increase was mild, similar to what has been observed in human SLE.

Biological variation of 20 analytes measured in serum from clinically healthy domestic cats.

The applications of data on biological variation include assessment of the utility of population-based reference intervals, evaluation of the significance of change in serial results, and setting of analytical quality specifications. We investigated the biological variation of 19 biochemistry analytes and total T4, measured in serum from 7 clinically healthy domestic cats sampled once weekly for 5 weeks. Samples were frozen and analyzed in random order in the same analytical run. Results were analyzed for outliers, and the components of variance, subsequently generated by restricted maximum likelihood, were used to determine within-subject and between-subject variation (CVI and CVG, respectively), as well as analytical variation (CVA) for each analyte. Indices of individuality, reference change values, and analytical performance goals were calculated. The smallest CVI and CVG were found for calcium, chloride, and sodium, whereas the largest values were calculated for bile acids. Nine analytes (albumin, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, cholesterol, creatinine, phosphate [phosphorus], total protein, total T4) demonstrated high individuality, indicating limited utility of population-based reference intervals. Individuality was low, and population-based reference intervals were thereby considered appropriate for 5 analytes (bile acids, calcium, fructosamine, glucose, potassium). The intermediate individuality observed for 4 analytes (creatine kinase, iron, magnesium, urea) indicated that population-based reference intervals should be used with caution.

Validation and application of a canine-specific automated high-sensitivity C-reactive protein assay.

Measurement of low concentrations of C-reactive protein (CRP) in dogs has previously been performed with nonautomated assays. The aim of this study was to validate an automated high-sensitivity CRP (hsCRP) assay, developed by modifying a routinely used canine-specific immunoturbidimetric CRP test (cCRP). Imprecision, linearity under dilution, limit of blank (LOB), limit of detection (LOD), and limit of quantification (LOQ) were determined for the hsCRP test, as well as the presence of prozone effect and interferences. The imprecision, measured as intra-assay variation, was ≤2.7%. The assay was acceptably linear under dilution. An analytically relevant prozone effect was present for samples with CRP concentration >150 mg/L, and there were mild interferences from hemolysis and lipemia. The LOB, LOD, and LOQ were 0.10 mg/L, 0.22 mg/L, and 0.50 mg/L, respectively. A method comparison study with a canine-specific enzyme-linked immunosorbent assay (ELISA) was performed, showing poor agreement between the hsCRP test and the ELISA. An additional aim of the study was to apply the hsCRP test to clinical research samples. Serum samples from 7 dogs undergoing ovariohysterectomy were collected pre- and postoperatively, and CRP was measured with both the cCRP and hsCRP assay. The expected postoperative increase in CRP was detected earlier with the hsCRP test, compared with the cCRP test. The hsCRP assay was further applied on samples from 6 lean and 9 overweight dogs. There was no significant difference in CRP concentration between the groups (P = 0.06). In conclusion, the hsCRP test had acceptable analytical performance, and the assay was successfully applied to clinical research samples.

Validation of a commercially available automated canine-specific immunoturbidimetric method for measuring canine C-reactive protein.

BACKGROUND: Measurement of C-reactive protein (CRP) is used for diagnosing and monitoring systemic inflammatory disease in canine patients. An automated human immunoturbidimetric assay has been validated for measuring canine CRP, but cross-reactivity with canine CRP is unpredictable. OBJECTIVE: The purpose of the study was to validate a new automated canine-specific immunoturbidimetric CRP method (Gentian cCRP). METHODS: Studies of imprecision, accuracy, prozone effect, interference, limit of quantification, and stability under different storage conditions were performed. The new method was compared with a human CRP assay previously validated for canine CRP determination. Samples from 40 healthy dogs were analyzed to establish a reference interval. RESULTS: Total imprecision was < 2.4% for 4 tested serum pools analyzed twice daily over 10 days. The method was linear under dilution, and no prozone effect was detected at a concentration of 1200 mg/L. Recovery after spiking serum with purified canine CRP at 2 different concentrations was 123% and 116%, respectively. No interference from hemoglobin or triglycerides (10 g/L) was detected. CRP was stable for 14 days at 4°C and 22°C. In the method comparison study, there was good agreement between the validated human CRP assay and the new canine-specific assay. Healthy dogs had CRP concentrations that were less than the limit of quantification of the Gentian cCRP method (6.8 mg/L). CONCLUSIONS: The new canine-specific immunoturbidimetric CRP assay is a reliable and rapid method for measuring canine CRP, suitable for clinical use due to the option for an automated assay.

Cytologic appearance of retinal cells included in a fine-needle aspirate of a meningioma around the optic nerve of a dog.

A 6-year-old Wirehair Dachshund had a meningioma around the optic nerve that caused exophthalmos. A benign mesenchymal tumor was suspected based on the cytologic pattern of a fine-needle aspirate, and a meningioma was diagnosed by histopathologic examination. In addition to the meningioma cells, the cytologic smears included groups of cells from apparently 4 layers of normal retina. In particular, uniform rod-shaped structures in the cytologic sample could suggest rod-shaped bacteria, but these structures were identified as cylindrical outer segments of photoreceptor rod cells. Other retinal structures recognized included pigmented epithelial layer cells with their uniquely formed pigment granules, the characteristic bi-lobed, cleaved nuclei from the outer nuclear layer, and nerve tissue likely from the outer plexiform layer of the retina.

Evaluation of cytologic findings in feline conjunctivitis.

BACKGROUND: Cytologic examination of smears prepared from ocular swabs of conjunctiva from cats with conjunctivitis permits identification of the type of inflammation and possibly specific microorganisms. Results of studies of the diagnostic utility of cytology for detection of infectious causes of feline conjunctivitis have been inconsistent. OBJECTIVES: The objectives of this study were to describe cytologic findings in cats with conjunctivitis and to compare those findings with results of PCR analysis for feline herpesvirus (FHV-1), Chlamydophila felis (C felis), and Mycoplasma felis (M felis). METHODS: Conjunctival smears from 88 cats with conjunctivitis and 10 healthy control cats were stained with a Romanowsky stain and evaluated for the type of inflammation and evidence of an infectious agent. PCR analysis for FHV-1, C felis, and M felis was performed. RESULTS: Infectious agents identified by PCR analysis were FHV-1 in 9 cats (10%), C felis in 8 cats (9%), and M felis in 6 cats (7%). Inclusions interpreted as chlamydial inclusions were found in all cytologic smears from cats positive for C felis by PCR analysis and in 3 PCR-negative cats. Inclusions interpreted as Mycoplasma organisms were found in 3 of 6 cats that were PCR-positive for M felis and in 1 PCR-negative cat. FHV-1 inclusion bodies were not detected on cytologic examination. CONCLUSIONS: Cytologic examination can be diagnostic for C felis infection when many typical inclusions are present. Cytologic examination was unreliable in diagnosing M felis infection, and viral inclusions of FHV-1 were not found in specimens stained with Romanowsky stains.

Evaluation of an in-clinic Serum Amyloid A (SAA) assay and assessment of the effects of storage on SAA samples.

BACKGROUND: An in-clinic assay for equine serum amyloid A (SAA) analysis, Equinostic EVA1, was evaluated for use in a clinical setting. Stability of SAA in serum samples was determined. METHODS: Intra- and inter- assay variation of the in-clinic method was determined. The in-clinic method (EVA1) results were compared to a reference method (Eiken LZ SAA) with 62 patient samples. For samples with SAA concentrations within the assay range of EVA1 (10-270 mg/L), differences between the methods were evaluated in a difference plot. Linearity under dilution was evaluated in two samples. Stability of SAA in three serum pools stored at 4 degrees C and approximately 22 degrees C was evaluated with the reference method day 0, 1, 2, 4, 7, 17 and analysed with a two-way ANOVA. RESULTS: The imprecision (coefficient of variation, CV) for the in-clinic method was acceptable at higher SAA concentrations with CV values of 7,3-12%, but poor at low SAA concentrations with CV values of 27% and 37% for intra- and inter-assay variation respectively. Recovery after dilution was 50-138%. The in-clinic assay and the reference method identified equally well horses with low (<10 mg/L) and high (>270 mg/L) SAA concentrations. Within the assay range of the in-clinic method, 10-270 mg/L, the difference between the two methods was slightly higher than could be explained by the inherent imprecision of the assays. There were no significant changes of serum SAA concentrations during storage. CONCLUSIONS: The in-clinic assay identified horses with SAA concentrations of <10 mg/L and >270 mg/L in a similar way as the reference method, and provided an estimate of the SAA concentration in the range of 10-270 mg/L. The imprecision of the in-clinic method was acceptable at high SAA concentrations but not at low concentrations. Dilution of samples gave inconsistent results. SAA was stable both at room temperature and refrigerated, and thus samples may be stored before analysis with the reference method.