Study of age-related changes in plasma metabolites and enzyme activity of healthy small dogs that underwent medical checkups

Introduction

In Japan, the importance of medical checkups for pet dogs is increasing. In this study, we retrospectively explored the effects of age on plasma biomarkers in healthy small dogs that underwent medical checkups.

Methods

Based on the modified American Animal Hospital Association Canine Life Stage Guidelines, 52 healthy small dogs were divided into 3 groups according to their life stage: young adult (1-4 years old), mature adult (5-11 years old), senior (12-15 years old). None of the dogs were obese. Plasma was collected from animals that underwent medical checkups at Muromi Animal Hospital (Fukuoka, Japan). Plasma glucose, triglyceride (TG), total protein, blood urea nitrogen (BUN), creatinine, total cholesterol, and albumin concentrations; alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase (ALP) activities; c-reactive protein (CRP), non-esterified fatty acid, malondialdehyde (MDA), serum amyloid A (SAA), insulin, and adiponectin (ADN) concentrations; glutathione peroxidase (GPx), superoxide dismutase (SOD), malate dehydrogenase (MDH), and lactate dehydrogenase (LDH) activities; and M/L ratio (MDH/LDH) were examined. Changes in the abovementioned plasma biomarker levels were compared between canines in different life stages.

Results

Plasma ADN concentrations and GPx, SOD, and MDH activities significantly decreased with age, whereas plasma ALP, BUN, TG, and MDA concentrations gradually increased. Plasma SAA levels measured by the latex agglutination method in 51 of the 52 small dogs that underwent medical checkups were below the detection limit.

Conclusion

Plasma ADN concentrations, GPx, SOD activity, and BUN levels may be important biomarkers for clarifying the effect of age in healthy dogs that undergo medical checkups. However, plasma SAA values obtained by the latex agglutination method were not considered an age-related inflammation marker for healthy dogs.

Point-of-care and traditional erythrocyte sedimentation rate, point-of-care rheometry, and cell-free DNA concentration in dogs with or without systemic inflammation

RBC aggregation and deformability characteristics are altered by inflammatory, microcirculatory, and hemorheologic disease. These changes can be indirectly evaluated using the erythrocyte sedimentation rate (ESR). Newer point-of-care devices employ syllectometry to evaluate RBC rheology, which can give information beyond the ESR. We evaluated 2 point-of-care rheometers (iSED and MIZAR; Alcor Scientific) in 52 dogs presented to a university teaching hospital. Whole blood samples were analyzed for correlation between the ESR using the Westergren (ESRw) method (measured at 1 h and 24 h) and the predicted ESR using iSED. Plasma fibrinogen and cell-free DNA concentrations were also measured as probable markers of inflammation. The iSED-predicted ESR was positively correlated to the ESRw method at 1 h (r = 0.74; p < 0.001) and 24 h (r = 0.62; p < 0.001). Comparing dogs with or without inflammation (defined as plasma fibrinogen concentration >3.5 g/L [350 mg/dL]), significant differences were seen in the MIZAR parameters of base point, amplitude, integral, and half-time. Median cell-free DNA concentrations were higher in the group of dogs with inflammation (117 [range: 51-266] ng/mL vs. 82.7 [range: 19-206] ng/mL; p = 0.024). The iSED-predicted ESR is a good predictor of the ESRw and was obtained more rapidly. Rheometric parameters measured by MIZAR may be useful in detecting inflammation and monitoring secondary morphologic and functional changes in canine RBCs.

Development and clinical evaluation of a quantitative fluorescent immunoassay for detecting canine CRP

Canine C-reactive protein (cCRP) is one of the major positive acute phase proteins in dogs and is commonly measured to detect and monitor systemic inflammation as well as the efficacy of treatment. Traditional methods for testing cCPR, including enzyme-linked immunosorbent assay (ELISA), have some drawbacks, such as a long time for diagnosis and the requirement of well-equipped laboratories. Therefore, there is a need for a rapid and precise diagnostic test for cCRP at point-of-care. This study assessed the accuracy, precision, and validated clinical effectiveness of a diagnostic test based on fluorescent lateral flow immunoassay to detect cCRP. For the standard cCRP concentration ranging from 0 to 200 μg/mL, the cCRP diagnostic test showed strong linearity with R2 of 0.9977 (p < 0.001), and both inter- and intra-assay CVs were <14%. The limit of detection and limit of quantitation were found to be 4.0 μg/mL and 5.0 μg/mL, respectively. The cCRP serum concentration was evaluated in 21 client-owned dogs and the results were compared to a previously validated ELISA. The Pearson Correlation Coefficient between the diagnostic test kit and ELISA was 0.942 [95% confidence interval: 0.859 to 0.976, p < 0.001], and the Bland-Altman plot indicated a bias of 26.82% [95% limits of agreement: -56.03 to 109.67], indicating a significant correlation and the agreement between the data from the cCRP diagnostic test and ELISA. In conclusion, the fluorescent immunoassay based diagnostic test is a suitable option for rapidly and precisely detecting cCRP in dogs, providing a convenient alternative to traditional methods for diagnosing acute inflammation.

Serum amyloid A and other clinicopathological variables in cats with intermediate- and large-cell lymphoma

OBJECTIVES

Serum amyloid A (SAA) concentrations are increased in cats with lymphoma vs healthy cats; however, the association between SAA concentrations and prognosis in cats with lymphoma is unclear. The aim of this study was to evaluate if SAA concentrations were different in cats with nasal vs non-nasal lymphoma, if SAA concentrations are prognostic in patients treated with high-dose chemotherapy and if SAA concentrations are correlated with other clinicopathological variables.

METHODS

Cats diagnosed with intermediate- or large-cell lymphoma between 2012 and 2022 with SAA concentration data available were included. Associations between tumour site (nasal vs non-nasal), stage, response to treatment and SAA concentration were evaluated using non-parametric statistics. Associations between SAA concentrations and stage with survival time were evaluated using Cox regression analysis. Patients with nasal tumours and those not receiving high-dose chemotherapy were excluded from the survival analyses.

RESULTS

Thirty-nine cats were included. Median SAA concentrations were significantly higher in non-nasal compared with nasal lymphoma (42 µg/ml [range <0.3-797] vs <0.3 µg/ml [range <0.3-0.9]; P = 0.026). SAA concentrations did not correlate with tumour stage. Median survival time for patients with non-nasal tumour and undergoing chemotherapy was 49 days (range 2-1726). Responders had a better median survival time than non-responders (273 days [range 43-1728] vs 39 days [range 2-169]; P <0.001), whereas SAA concentrations were not associated with survival time. Lower haematocrit at presentation was associated with a reduced median survival time (P = 0.007).

CONCLUSIONS AND RELEVANCE

In the population examined, no correlation between serum concentration of SAA and prognosis in patients with lymphoma was identified, while low haematocrit and lack of response to treatment were both found to be associated with survival time. SAA concentrations were elevated in patients with non-nasal lymphoma vs patients with tumours confined to the nasal cavity.

Development and validation of a multivariable model and online decision-support calculator to aid in preoperative discrimination of benign from malignant splenic masses in dogs

OBJECTIVE

To develop a multivariable model and online decision-support calculator to aid in preoperative discrimination of benign from malignant splenic masses in dogs.

ANIMALS

522 dogs that underwent splenectomy because of splenic masses.

PROCEDURES

A multivariable model was developed with preoperative clinical data obtained retrospectively from the records of 422 dogs that underwent splenectomy. Inclusion criteria were the availability of complete abdominal ultrasonographic examination images and splenic histologic slides or histology reports for review. Variables considered potentially predictive of splenic malignancy were analyzed. A receiver operating characteristic curve was created for the final multivariable model, and area under the curve was calculated. The model was externally validated with data from 100 dogs that underwent splenectomy subsequent to model development and was used to create an online calculator to estimate probability of splenic malignancy in individual dogs.

RESULTS

The final multivariable model contained 8 clinical variables used to estimate splenic malignancy probability: serum total protein concentration, presence (vs absence) of ≥ 2 nRBCs/100 WBCs, ultrasonographically assessed splenic mass diameter, number of liver nodules (0, 1, or ≥ 2), presence (vs absence) of multiple splenic masses or nodules, moderate to marked splenic mass inhomogeneity, moderate to marked abdominal effusion, and mesenteric, omental, or peritoneal nodules. Areas under the receiver operating characteristic curves for the development and validation populations were 0.80 and 0.78, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

The online calculator (T-STAT.net or T-STAT.org) developed in this study can be used as an aid to estimate the probability of malignancy in dogs with splenic masses and has potential to facilitate owners' decisions regarding splenectomy.

Comparison of Protein Carbonyl (PCO), Paraoxonase-1 (PON1) and C-Reactive Protein (CRP) as Diagnostic and Prognostic Markers of Septic Inflammation in Dogs

Reliable diagnostic and prognostic markers of sepsis are lacking, but essential in veterinary medicine. We aimed to assess the accuracy of C-Reactive Protein (CRP), protein carbonyls (PCO) and paraoxonase-1 (PON1) in differentiating dogs with sepsis from those with sterile inflammation and healthy ones, and predict the outcome in septic dogs. These analytes were retrospectively evaluated at admission in 92 dogs classified into healthy, septic and polytraumatized. Groups were compared using the Kruskal–Wallis test, followed by a Mann–Whitney U test to assess differences between survivors and non-survivors. Correlation between analytes was assessed using the Spearman’s test, and their discriminating power was assessed through a Receiver Operating Characteristic (ROC) curve. PON1 and CRP were, respectively, significantly lower and higher in dogs with sepsis compared with polytraumatized and clinically healthy dogs (p < 0.001 for both the analytes), and also in dogs with trauma compared with healthy dogs (p = 0.011 and p = 0.017, respectively). PCO were significantly increased in septic (p < 0.001) and polytraumatized (p < 0.005) as compared with healthy dogs. PON1 and CRP were, respectively, significantly lower and higher in dogs that died compared with survivors (p < 0.001 for both analytes). Ultimately, evaluation of CRP and PON1 at admission seems a reliable support to diagnose sepsis and predict outcomes.

Plasma 25-hydroxyvitamin D and the inflammatory response in canine cancer

Decreased circulating 25-hydroxyvitamin D (25[OH]D) and increased inflammatory marker concentrations have been reported separately in canine cancer. Correlations between the two exist in humans, but little work has examined links in dogs. This study aimed to determine plasma 25(OH)D and inflammatory marker concentrations in healthy dogs and dogs with cancer and to assess correlations in each group. Newly diagnosed dogs with B-cell lymphoma (B-cell, n = 25), T-cell lymphoma (T-cell, n = 9), osteosarcoma (OSA, n = 21), and mast cell tumour (MCT, n = 26) presenting to a tertiary oncology centre, and healthy dogs (n = 25), were enrolled. Plasma samples were analysed for 25(OH)D, C-reactive protein (CRP), haptoglobin (HP), serum amyloid A (SAA), alpha-1-acid glycoprotein (AAG), and 13 chemokines and cytokines. Dogs with B-cell had decreased plasma 25(OH)D (P = .03), and increased plasma CRP, AAG, HP, KC-like and MCP-1 concentrations (P < =.001, .011, <.001, .013 and .009, respectively) compared with healthy dogs. Plasma CRP, HP and SAA concentrations were increased in dogs with OSA compared with healthy dogs (P = .001, .010 and .027, respectively). No differences were noted in dogs with T-cell and MCT. Negative correlations were observed between plasma 25(OH)D concentrations and: AAG concentrations in dogs with T-cell (R_s  = -0.817, P = .007); GM-CSF concentrations (R_s  = -0.569, P = .007) in dogs with OSA; and IL-7 concentrations (R_s  = -0.548, P = .010) in dogs with OSA. Decreased 25(OH)D concentrations and increased concentrations of multiple inflammatory markers were observed in B-cell patients, supporting an association between 25(OH)D and inflammation. The cross-sectional study design meant the timing of changes could not be determined. Prospective cohort studies are warranted.

Primary Adenosquamous Cell Carcinoma of the Ileum in a Dog

A 9-year-old male, castrated Chihuahua was examined because of a 7-day history of intermittent vomiting. A mass in the small intestine was identified on abdominal radiography and ultrasonography. Laparotomy revealed a mass lesion originating in the ileum, and surgical resection was performed. The mass was histologically diagnosed as adenosquamous cell carcinoma. Chemotherapy with carboplatin was initiated, but the dog was suspected to have experienced recurrence 13 months after surgery and died 3 months later. To our knowledge, this is the first case report to describe the clinical course of adenosquamous cell carcinoma in the small intestine of a dog.

Comparison of body condition score and other minimally invasive biomarkers between dogs with gastric carcinoma and dogs with chronic gastritis

OBJECTIVE To identify minimally invasive biomarkers to help differentiate dogs with gastric carcinoma from those with chronic gastritis. DESIGN Prospective study. ANIMALS 15 dogs with gastric carcinoma, 29 dogs with chronic gastritis, and 7 healthy dogs. PROCEDURES Dogs with clinical signs of upper gastrointestinal tract disease for > 14 days that underwent gastroscopy or necropsy for collection of gastric biopsy specimens for histologic evaluation were prospectively enrolled. Gastric carcinoma and chronic gastritis were diagnosed on the basis of histologic findings. Additionally, gastric biopsy specimens were collected endoscopically from 7 healthy (control) dogs while they were anesthetized for a routine neutering procedure. Prior to being anesthetized for gastroscopy or euthanized, all dogs underwent a physical examination, and a blood sample was collected for quantification of select serum biomarker concentrations. Histologic findings, body condition score (BCS), and serum biomarker concentrations were compared among the 3 groups. RESULTS Dogs with gastric carcinoma were significantly older and had a significantly lower BCS, lower serum folate concentration, and greater serum C-reactive protein (CRP) concentration, compared with dogs with chronic gastritis and control dogs. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that age > 8 years, BCS < 4, serum CRP concentration > 25 mg/L, and an abnormally low serum folate concentration might be useful noninvasive biomarkers for identification of dogs with gastric carcinoma. For underweight older dogs with signs of upper gastrointestinal tract disease and high serum CRP and low serum folate concentrations, gastric biopsy specimens should be obtained and evaluated so that a prompt definitive diagnosis can be made and appropriate treatment initiated.

Comparison of biomarkers adiponectin, leptin, C-reactive protein, S100A12, and the Acute Patient Physiologic and Laboratory Evaluation (APPLE) score as mortality predictors in critically ill dogs

OBJECTIVES

To determine if selected serum biomarkers are superior to the acute patient physiologic and laboratory evaluation (APPLE) complete score in predicting 30-day mortality in a non-homogeneous disease population of critically ill dogs.

DESIGN

Prospective cohort study comparing the serum biomarkers adiponectin, leptin, C-reactive protein, and S100A12 concentrations between surviving and nonsurviving critically ill dogs.

SETTING

University small animal teaching hospital.

ANIMALS

Seventy critically ill dogs were prospectively recruited, and an APPLE complete score was calculated within 24 hours of being admitted to the intensive care unit. Logistic regression models were fit to estimate the association between biomarkers and 30-day survival. Results were interpreted at the 5% level of significance.

MEASUREMENTS AND MAIN RESULTS

Leptin was the only biomarker that was significantly correlated with the APPLE complete score (P < 0.001). Only the APPLE complete score (P = 0.003) and illness duration of < 1 day (P = 0.043) were significantly associated with outcome.

CONCLUSION

Based on the results of this study, there appears to be no benefit in using biomarkers over the APPLE score for disease severity stratification. Serum leptin concentration was significantly correlated with disease severity as determined by APPLE scoring. Longer duration of illness prior to admission was associated with a higher risk of death. APPLE scores were highest in dogs with infectious and immune-mediated diseases and bite wounds.

Evaluation of a novel quantitative canine species-specific point-of-care assay for C-reactive protein

BACKGROUND

Species-specific point-of-care tests (POCT) permit a rapid analysis of canine C-reactive protein (CRP), enabling veterinarians to include CRP in clinical decisions. Aim of the study was to evaluate a novel POCT for canine CRP (Point Strip™ Canine CRP Assay) run on a small in-house-analyzer (Point Reader™ V) using lithium heparin plasma and to compare assay performance to an already established canine CRP assay (Gentian Canine CRP Immunoassay) run on two different bench top analyzers serving as reference methods (ABX Pentra 400, AU 5800). Linearity was assessed by stepwise dilution of plasma samples with high CRP concentrations. Limit of quantification (LoQ) was determined by repeated measurements of samples with low CRP concentrations. Coefficient of variation (CV) at low (10-50 mg/l), moderate (50-100 mg/l), and high (100-200 mg/l) CRP concentrations was investigated as well as possible interferences. Method comparison study was performed using 45 samples of healthy and diseased dogs. Quality criteria were fulfilled if the total observed error (TE_obs = 2CV% + bias%) was below the minimal total allowable error of 44.4% (TE _min). Additionally, a reference range (n = 60 healthy dogs) was established.

RESULTS

Linearity was present at CRP concentrations of 10-132 mg/l (≙ 361 mg/l CRP with reference method) with a LoQ set at 10 mg/l. At moderate to high CRP concentrations, intra- and inter-assay CVs were ≤ 8% and ≤ 11% respectively, while CVs ≤ 22% and ≤ 28% were present at low concentrations. No interferences were observed at concentrations of 4 g/l hemoglobin, 800 mg/l bilirubin and 8 g/l triglycerides. Method comparison study demonstrated an excellent correlation with both reference methods (r = 0.98 for ABX Pentra 400; 0.99 for AU 5800), though revealing a proportional bias of 19.7% (ABX Pentra 400) and 10.7% (AU 5800) respectively. TE_obs was 26.7-31.9% and 16.7-21.9% and thus < TE_min. Healthy dogs presented with CRP values ≤11.9 mg/l.

CONCLUSIONS

The POCT precisely detects canine CRP at clinically relevant moderate and high CRP concentrations. The assay correlates well with both reference methods. Due to the bias, however, follow-up examinations should be performed with the same assay and analyzer.

MMP-2 as an early synovial biomarker for cranial cruciate ligament disease in dogs

Objectives: To measure the activity of matrix metalloproteinases (MMP)-2 and -9 in synovial fluid from the stifle joints of dogs with cranial cruciate ligament (CrCL) rupture and to compare that to values from contralateral stifle joints and dogs with clinically normal stifle joints. Additionally, the C-reactive protein (CRP) levels were also measured.

Methods: Fourteen large breed dogs with unilateral CrCL rupture and 11 large breed normal dogs were included in this prospective clinical study. Synovial fluid was collected from CrCL-ruptured stifle joints, contralateral clinically normal stifle joints of the same dogs, and stifle joints of normal dogs. Serum was also collected. Synovial fluid activities of MMP-2 and MMP-9 and serum CRP level were measured.

Results: The MMP-2 activity in synovial fluid was significantly higher in CrCL-ruptured joints compared to contralateral joints and to stifles from normal dogs. There was no significant difference in activity of MMP-2 in contralateral joints of CrCL-ruptured dogs compared to normal dogs. Both serum CRP level and MMP-9 activity did not differ significantly between the studied conditions.

Clinical significance: It was confirmed that MMP-2 activity is significantly related to CrCL rupture, but there was a failure to demonstrate any significant increase in the contralateral joints compared to the stifle joints of normal dogs. The MMP-2 involvement in progressing CrCL disease still has to be defined.

Inflammatory cytokine and C-reactive protein concentrations in dogs with systemic inflammatory response syndrome

OBJECTIVE

To evaluate C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor alpha (TNF-α) kinetics in dogs with a systemic inflammatory response syndrome (SIRS) presented to an emergency service. We hypothesized serum CRP concentrations would increase and vary during hospitalization, and would correlate with plasma IL-6 and TNF-α concentrations, vary in magnitude according to the underlying disease, and predict survival.

DESIGN

Prospective, observational, clinical study.

SETTING

University emergency department.

ANIMALS

Sixty-nine dogs with SIRS weighing over 5 kg who could tolerate the blood sampling.

INTERVENTIONS

Serum and plasma were collected (and stored at -80°C) at presentation (T0), after 6 (T6), 12 (T12), 24 (T24), and 72 (T72) hours, and at a follow-up visit at least 1 month after discharge (T1m). Underlying diseases were categorized as infection (I), neoplasia (N), trauma (T), gastric-dilation and volvulus (GDV), other gastrointestinal (GI), renal (R), and miscellaneous (M) disease.

MEASUREMENTS AND MAIN RESULTS

Serum CRP concentration was measured using a canine-specific immunoturbidimetric assay. Biologically active plasma IL-6 and TNF-α concentrations were assessed using bioassays. Forty-four dogs survived, 8 died, and 17 were euthanized. Nineteen dogs had follow-up visits. At T0, serum CRP concentration was above the reference interval in 73.1% (49/67), and was within the reference interval (0-141.9 nmol/L) throughout hospitalization in only 6% (4/67). Serum CRP concentrations were significantly higher (P < 0.0001) at T0 (882.9 ± 1082.9 nmol/L) and at all time points during hospitalization (P < 0.0001) compared to T1m, with highest concentrations observed at T24 (906. 7 ± 859.0 nmol/L). At T1m, serum CRP concentrations were within the reference interval (22.9 ± 42.9 nmol/L) in 95% (18/19) of dogs. Logarithmic concentrations of serum CRP and plasma IL-6 were significantly correlated (P < 0.001, r = 0.479). None of the measured cytokines were associated with disease category or outcome.

CONCLUSIONS

Serum CRP concentration is increased in dogs with SIRS, and decreases during treatment and hospitalization. Serum CRP, plasma IL-6, and plasma TNF-α concentrations cannot predict outcome in dogs with SIRS.

Serum Thymidine Kinase 1, Canine-C-Reactive Protein, Haptoglobin, and Vitamin D Concentrations in Dogs with Immune-Mediated Hemolytic Anemia, Thrombocytopenia, and Polyarthropathy

Background

Relapses of immune‐mediated hemolytic anemia (IMHA), thrombocytopenia (ITP), or polyarthropathy (IMPA) occur despite normal hematologic and cytologic parameters. Thymidine kinase 1 (TK1), canine C‐reactive protein (c‐CRP), haptoglobin (HPT), and 25‐Hydroxyvitamin‐D (25(OH)D) might be adjunct to current monitoring strategies.

Hypothesis/Objectives

Compare serum concentrations of TK1, c‐CRP, HPT, and 25(OH)D in dogs with well‐ and poorly controlled primary IMHA, ITP, or IMPA.

Animals

Thirty‐eight client‐owned dogs.

Methods

Prospective descriptive study. Dogs diagnosed with IMHA, ITP, or IMPA had serum biomarker concentrations measured commercially. Disease control was assessed by hematocrit/PCV and reticulocyte count, platelet count, and synovial fluid cytology for IMHA, ITP, and IMPA, respectively. Statistical analysis performed by Mann‐Whitney rank‐sum tests and receiver operating characteristic curves.

Results

TK1 and c‐CRP, but not HPT significantly decreased with well‐ versus poorly controlled IMHA (P = 0.047, P = 0.028, P = 0.37). C‐CRP, but not TK or HPT was significantly lower with well‐ versus poorly controlled IMPA (P = 0.05, P = 0.28, P = 0.84). Sensitivity and specificity of TK and c‐CRP (simultaneously) for detecting dogs with poorly controlled IMHA were 88 and 100%, respectively. Sensitivity and specificity of c‐CRP for detecting poorly controlled dogs with IMPA were 13 and 100%, respectively. 92% of dogs were vitamin D insufficient (<100 ng/mL) regardless of disease control.

Conclusions and Clinical Importance

Combining TK1 and c‐CRP might act markers of disease control in dogs with IMHA. Canine‐CRP cannot be recommended as an independent marker of disease control in IMPA. 25(OH)D insufficiency in immune‐mediated disorders might benefit from further study to determine if supplementation could improve therapeutic response or reduce disease risk.

Evaluation of a species-specific C-reactive protein assay for the dog on the ABX Pentra 400 clinical chemistry analyzer

Background

A canine-specific immunoturbidimetric CRP assay, Gentian Canine CRP Immunoassay) with species-specific controls and calibrators was introduced and recently evaluated on the clinical chemistry analyzer Abbott Architect c4000 as well as on the Olympus AU600.

Aims of our study were 1) to independently evaluate the canine-specific CRP assay on the ABX Pentra 400 clinical chemistry analyzer in comparison to the previously validated human-based immunoturbidimetric assay (Randox Canine CRP assay) and 2) to assess the impact of different sample types (serum versus heparinized plasma) on the results.

Imprecision, accuracy, interference and the prozone effect were determined using samples from healthy and diseased dogs (n = 278). The Randox Canine CRP assay calibrated with canine specific control calibration material served as a reference method. Additionally, the impact of the sample type (serum and lithium heparin) was evaluated based on samples of healthy and diseased dogs (n = 49) in a second part of the study.

Results

Linearity was present for CRP concentrations ranging from 4 to 281 mg/l. For clinically relevant CRP concentrations of 7–281 mg/l, recovery ranged between 90 and 105% and intra- and inter-assay CVs ranged between 0.68% - 12.12% and 0.88% - 7.84%, respectively. CV was thus lower than 12.16%, i.e. the desired CV% based on biological variation. Interference was not present up to a concentration of 5 g/l hemoglobin, 800 mg/l bilirubin and 10 g/l triglycerides. No prozone effect occurred up to 676 mg/l CRP. Method comparison study revealed a Spearman’s rank correlation coefficient of r_s = 0.98 and a mean constant bias of 5.2%. The sample type had a significant (P = 0.008) but clinically not relevant impact on the results (median CRP of 30.9 mg/l in lithium heparin plasma versus 31.4 mg/l in serum).

Conclusions

The species-specific Gentian Canine CRP Immunoassay reliably detects canine CRP on the ABX Pentra 400 clinical chemistry analyzer whereby both serum and heparin plasma can be used. The quality criteria reached on the Abbott Architect c4000 and Olympus AU600 could be met.

The Utility of Acute-Phase Proteins in the Assessment of Treatment Response in Dogs With Bacterial Pneumonia

Background

Acute‐phase proteins (APPs) are sensitive markers of inflammation, and serum C‐reactive protein (CRP) recently has been shown to be a useful diagnostic marker in dogs with bacterial pneumonia (BP). In humans with community‐acquired pneumonia, APPs also have great utility as follow‐up markers aiding in the assessment of treatment response.

Objectives

The aim of our study was to investigate the applicability of APPs as markers of treatment response in dogs with BP.

Animals

Nineteen dogs diagnosed with BP and 64 healthy dogs.

Methods

The study was conducted as a prospective longitudinal observational study. Serum CRP, serum amyloid A (SAA), and haptoglobin concentrations were followed during a natural course of BP. Normalization of serum CRP was used to guide the duration of antibiotic treatment (treatment was stopped 5–7 days after CRP normalized) in 8 of 17 dogs surviving to discharge; 9 of 17 dogs were treated according to conventional recommendations.

Results

All measured APPs initially were significantly increased, but the magnitude of increase was not correlated to disease severity. C‐reactive protein and SAA concentrations decreased rapidly after initiation of antimicrobial treatment. When normalization of serum CRP was used to guide the duration of antibiotic treatment, treatment duration was significantly (P = .015) decreased without increasing the number of relapses.

Conclusions and Clinical Importance

Serum CRP and SAA reflected the recovery process well and therefore may be used as markers of treatment response. According to the results, the normalization of serum CRP may be used to guide the duration of antibiotic treatment in dogs with BP.

Serum α-1 acid glycoprotein and serum amyloid A concentrations in cats receiving antineoplastic treatment for lymphoma

OBJECTIVE To characterize serum α-1 acid glycoprotein (AGP) and serum amyloid A (SAA) concentrations at diagnosis and during treatment in cats with lymphoma. ANIMALS 16 cats with various anatomic forms of lymphoma and 25 healthy cats. PROCEDURES Blood samples were collected from healthy cats once and from cats with lymphoma at diagnosis and 2-week intervals until the 12th week of antineoplastic treatment. Serum harvested from blood samples was assessed for AGP and SAA concentrations. Differences in serum AGP and SAA values were investigated between healthy cats and cats with lymphoma (at diagnosis) and, for cats with lymphoma, between diagnosis and various points during treatment. RESULTS Serum AGP and SAA concentrations were higher in cats with lymphoma at diagnosis (median, 832.60 and 1.03 μg/mL, respectively), compared with those in healthy cats (median, 269.85 and 0.10 μg/mL). Treatment resulted in a gradual decrease in serum AGP concentration after 4 weeks and in SAA concentration after 8 weeks of treatment, and these concentrations returned to values comparable with those of healthy cats by 12 weeks of treatment, by which point all cats had achieved complete remission of the disease. CONCLUSIONS AND CLINICAL RELEVANCE Serum AGP and SAA concentrations in cats with lymphoma were higher at diagnosis than after antineoplastic treatment. Decreases to values established for healthy cats corresponded with achievement of complete disease remission. Serum AGP and SAA may be useful protein markers for monitoring of antineoplastic treatment in cats with lymphoma.

Serum C-reactive protein and S100A12 concentrations in dogs with hepatic disease

OBJECTIVES

To describe serum C-reactive protein and S100A12 concentrations in dogs with hepatic disease and to determine whether there is a relationship between the concentration of either and the severity of hepatic necroinflammation.

METHODS

Serum C-reactive protein and S100A12 concentrations were measured in 46 dogs undergoing hepatic biopsy. Dogs were divided into three groups: congenital portosystemic shunts, chronic hepatitis and hepatic neoplasia. The histological severity of hepatic necroinflammation was scored.

RESULTS

C-reactive protein and S100A12 concentrations were greater than the upper limit of the reference intervals in 39 and 26% of dogs, respectively. There was no association of disease group with C-reactive protein (P=0·1733) or S100A12 (P=0·1513) concentrations. There was a positive correlation between serum C-reactive protein concentration and hepatic necroinflammatory activity (rs =0·428, P=0·006).

CLINICAL SIGNIFICANCE

Increased serum C-reactive protein and S100A12 concentrations were observed in a subpopulation of dogs with various types of hepatic diseases, suggesting acute-phase inflammation and activation of phagocytic cells, respectively. Dogs with higher hepatic necroinflammatory activity scores tended to have higher serum C-reactive protein concentrations. Further studies are needed to confirm this finding in a larger group of dogs.

Biomarkers for differentiation of causes of respiratory distress in dogs and cats: Part 2--Lower airway, thromboembolic, and inflammatory diseases

OBJECTIVES

To review the current veterinary and relevant human literature regarding biomarkers of respiratory diseases leading to dyspnea and to summarize the availability, feasibility, and practicality of using respiratory biomarkers in the veterinary setting.

DATA SOURCES

Veterinary and human medical literature: original research articles, scientific reviews, consensus statements, and recent textbooks.

HUMAN DATA SYNTHESIS

Numerous biomarkers have been evaluated in people for discriminating respiratory disease processes with varying degrees of success.

VETERINARY DATA SYNTHESIS

Although biomarkers should not dictate clinical decisions in lieu of gold standard diagnostics, their use may be useful in directing care in the stabilization process. Serum immunoglobulins have shown promise as an indicator of asthma in cats. A group of biomarkers has also been evaluated in exhaled breath. Of these, hydrogen peroxide has shown the most potential as a marker of inflammation in asthma and potentially aspiration pneumonia, but methods for measurement are not standardized. D-dimers may be useful in screening for thromboembolic disease in dogs. There are a variety of markers of inflammation and oxidative stress, which are being evaluated for their ability to assess the severity and type of underlying disease process. Of these, amino terminal pro-C-type natriuretic peptide may be the most useful in determining if antibiotic therapy is warranted. Although critically evaluated for their use in respiratory disorders, many of the biomarkers which have been evaluated have been found to be affected by more than one type of respiratory or systemic disease.

CONCLUSION

At this time, there are point-of-care biomarkers that have been shown to reliably differentiate between causes of dyspnea in dogs and cats. Future clinical research is warranted to understand of how various diseases affect the biomarkers and more bedside tests for their utilization.

Correlation of serum cardiac troponin I and acute phase protein concentrations with clinical staging in dogs with degenerative mitral valve disease

BACKGROUND

Cardiac troponin I (cTnI) correlates with severity of myocardial injury. Nonspecific inflammation in congestive heart failure (CHF) could be assessed by C-reactive protein (CRP), haptoglobin (Hp), and ceruloplasmin (Cp) measurements.

OBJECTIVES

The aim of the study was to determine whether serum cTnI, CRP, Hp, and Cp concentrations differ among various stages of mitral valve disease (MVD) in dogs.

MATERIALS AND METHODS

Dogs with MVD were allocated to 3 groups (I - asymptomatic; II - mild to moderate CHF; III advanced CHF) according to the scheme of the International Small Animal Cardiac Healthy Council (ISACHC). Concentrations of cTnI, CRP, Cp, and Hp were measured in all dogs upon admission, and cTnI and CRP were measured bimonthly during a 4-month follow-up period.

RESULTS

In total 46 dogs with MVD were enrolled for the cross-sectional part (21 Group I, 11 Group II, 14 Group III), and 35 dogs were included in the longitudinal study. Initial mean Cp concentrations were similar among all groups. There was a statistically significant difference in Hp and CRP concentrations between group I (n = 21, P = .019) and III (n = 14, P < .001). There was a statistically significant decrease in CRP (P = .033) and cTnI (P = .009) concentrations over the longitudinal study (all groups). CRP concentrations were significantly higher in group I than III (P = .004). During the 6-month monitoring period of 35 dogs, there was a statistically significant positive correlation between cTnI and CRP (P < .001).

CONCLUSION

Differences in CRP concentrations between clinical stages of MVD suggest a clinically and therapeutically relevant inflammatory component.

Plasma iron, C-reactive protein, albumin, and plasma fibrinogen concentrations in dogs with systemic inflammatory response syndrome

OBJECTIVE

To investigate the diagnostic and prognostic value over time of plasma iron compared with the inflammatory markers albumin, C-reactive protein (CRP), and fibrinogen in dogs with systemic inflammatory response syndrome (SIRS).

DESIGN

Prospective observational study of sequentially enrolled dogs.

SETTING

ICU of a veterinary teaching hospital.

ANIMALS

One hundred and sixteen client-owned dogs: 54 dogs with SIRS or sepsis, 42 with focal inflammation, and 20 clinically healthy dogs.

MEASUREMENTS AND MAIN RESULTS

Blood samples were obtained on admission in all study groups, and then on alternate days until discharge or death in both inflammation groups. On admission, dogs with SIRS had significantly lower plasma iron (65 ± 5.8 μg/dL, P = 0.001) concentrations than dogs with focal inflammation (89.5 ± 6.2 μg/dL, P = 0.001). Plasma iron, albumin, and CRP effectively discriminated the SIRS/sepsis group from those presenting with focal inflammation with areas under the curve for the receiver operating curves of 0.679, 0.834, and 0.704, respectively. The admission values for these variables did not discriminate survivors from nonsurvivors within the SIRS/sepsis group. However, the magnitude of increase in iron concentration and the decrease in CRP concentration from admission to hospital discharge was higher in survivors than in nonsurvivors within the SIRS/septic group (22.8 vs. 2.51 μg/dL, respectively, P = 0.021 for iron; -67.1 vs. -4.1 mg/L, respectively, P = 0.002 for CRP), resulting in iron and CRP concentrations at hospital discharge for survivors similar to those in the focal inflammation group.

CONCLUSION

Hypoferremia is a sensitive marker of systemic inflammation in dogs. In this study, the increase in iron concentrations during the hospitalization period of SIRS/septic dogs was associated with a better prognosis, suggesting that plasma iron in combination with CRP and albumin concentrations might be used to monitor dogs with inflammatory disease processes.

Canine demodicosis: the relationship between response to treatment of generalised disease and markers for inflammation and oxidative status

BACKGROUND

Determination of acute phase proteins and markers of oxidative status may be of value for evaluating the severity of disease and the response to treatment. In canine demodicosis, there is no information available regarding the use of such analytes to discriminate between localized and generalized demodicosis or to monitor the response to treatment.

HYPOTHESIS/OBJECTIVES

The aim was to measure analytes related to inflammation and oxidative stress in dogs with localized or generalized demodicosis. In cases of generalized demodicosis, the intention was to study these analytes before and after a period of treatment.

ANIMALS

Serum was obtained from three groups: Group 1, healthy dogs; Group 2, dogs with localized demodicosis; and Group 3, dogs with generalized demodicosis.

METHODS

Animals from Groups 1 and 2 were sampled at the point of diagnosis. Dogs in Group 3 were treated with oral ivermectin 1% at 0.6 mg/kg once daily, and samples were collected at the point of diagnosis and after 30 days of treatment. C-Reactive protein, haptoglobin, albumin, butyrylcholinesterase, paraoxonase-1 and total antioxidant capacity were measured.

RESULTS

Dogs with generalized demodicosis had significantly higher concentrations of C-reactive protein and haptoglobin and lower butyrylcholinesterase activity than dogs in Groups 1 and 2. Dogs in Group 3 also had lower paraoxonase-1 than those in Group 2, The analytes tended to normalize during treatment.

CONCLUSIONS AND CLINICAL IMPORTANCE

There was an evident acute phase response and changes in selected oxidative state analytes in generalized demodicosis that do not occur in the localized form. These changes could be used for monitoring the response to treatment.

Cancer screening tests for small animals

Cancer is increasingly more common. Several tests for the diagnosis and treatment of cancer in companion animals have been developed. Screening tests discussed include those for lymphoid neoplasia, hemangiosarcoma, and transitional cell carcinoma of the bladder. None of these tests should be used in isolation for diagnosis. Vincristine and doxorubicin are mainstays in the treatment of canine lymphoma. However, it is important and accepted practice to test individuals of predisposed breeds for this mutation before administering these drugs in a lymphoma protocol.

Influence of racing on the serum concentrations of acute-phase proteins and bone metabolism biomarkers in racing greyhounds

This study was designed to evaluate the influence of racing on the serum concentrations of the acute-phase proteins (APPs) C-reactive protein (CRP), haptoglobin (Hp) and serum amyloid A (SAA) in 32 endurance-racing greyhounds. The study also aimed to investigate the effect of a 7 km race on the bone biomarkers osteocalcin (OC), bone-specific alkaline phosphatase (b-ALP) and pyridinoline cross-links (PYD). Total white blood cell (WBC) count, and the serum concentrations of cortisol, tumour necrosis factor-α (TNF-α), vitamin D and testosterone were also determined. Blood samples were collected 24 h prior to (T0) and within 2 h of completion of the race (T1). Compared to baseline values, WBC count did not change significantly (P = 0.2300), serum cortisol, Hp and SAA increased, while TNF-α and CRP decreased (P <0.0001 for each). There were no significant differences between the pre- and post-race serum concentrations of OC and PYD (P = 0.9500 and P = 0.2600, respectively), but serum b-ALP increased significantly (P = 0.0004). Serum concentrations of vitamin D and testosterone increased after racing (P = 0.0100 and P <0.0001, respectively). In this study, a 7 km race stimulated an acute-phase response, demonstrated by significant increases in the serum concentrations Hp and SAA in racing greyhounds. Increased serum b-ALP post-race probably indicates a change in bone metabolism and deserves further study.

Identification of serum biomarkers in dogs naturally infected with Babesia canis canis using a proteomic approach

Background

Canine babesiosis is a tick-borne disease that is caused by the haemoprotozoan parasites of the genus Babesia. There are limited data on serum proteomics in dogs, and none of the effect of babesiosis on the serum proteome. The aim of this study was to identify the potential serum biomarkers of babesiosis using proteomic techniques in order to increase our understanding about disease pathogenesis.

Results

Serum samples were collected from 25 dogs of various breeds and sex with naturally occurring babesiosis caused by B. canis canis. Blood was collected on the day of admission (day 0), and subsequently on the 1st and 6th day of treatment.

Two-dimensional electrophoresis (2DE) of pooled serum samples of dogs with naturally occurring babesiosis (day 0, day 1 and day 6) and healthy dogs were run in triplicate. 2DE image analysis showed 64 differentially expressed spots with p ≤ 0.05 and 49 spots with fold change ≥2. Six selected spots were excised manually and subjected to trypsin digest prior to identification by electrospray ionisation mass spectrometry on an Amazon ion trap tandem mass spectrometry (MS/MS). Mass spectrometry data was processed using Data Analysis software and the automated Matrix Science Mascot Daemon server. Protein identifications were assigned using the Mascot search engine to interrogate protein sequences in the NCBI Genbank database.

A number of differentially expressed serum proteins involved in inflammation mediated acute phase response, complement and coagulation cascades, apolipoproteins and vitamin D metabolism pathway were identified in dogs with babesiosis.

Conclusions

Our findings confirmed two dominant pathogenic mechanisms of babesiosis, haemolysis and acute phase response. These results may provide possible serum biomarker candidates for clinical monitoring of babesiosis and this study could serve as the basis for further proteomic investigations in canine babesiosis.

Serum paraoxonase 1 activity in dogs: preanalytical and analytical factors and correlation with C-reactive protein and alpha-2-globulin

BACKGROUND

Serum activity of paraoxonase (PON1) decreases during inflammation in many species. Little information is available on paraoxon-based tests and the possible role of PON1 in dogs.

OBJECTIVES

The objectives of the study were to validate an automated paraoxon-based assay to measure PON1 activity in canine serum, to determine its stability under different storage conditions, to determine a reference interval (RI) in healthy dogs, and to assess whether PON1 is of comparable diagnostic value as C-reactive protein (CRP) and α2-globulins.

METHODS

Intra-assay and inter-assay imprecision, linearity under dilution (LUD), interference, and storage artifacts were evaluated. A PON1 RI was determined for healthy dogs, and PON1 activity, sensitivity, and specificity were compared with CRP and α2-globulins.

RESULTS

Intra- and inter-assay CVs were below 1.6% and 7.8%, respectively. The LUD test fitted the linear model. PON1 activity measurements were increased after addition of hemolysates and lipids, and after storage for 12 hours at room temperature, 72 hours at 4°C, and 6 months at -20°C. PON1 activity and CRP or α2-globulins did not correlate well. PON1 activity decreased significantly only in dogs with very high CRP concentrations. In contrast to CRP and α2-globulins, PON1 activity was not significantly different between dogs with and without inflammation.

CONCLUSIONS

The automated paraoxon-based method to assess serum canine PON1 activity was accurate and precise, but it was influenced by hemolysis, lipemia, and standard storage conditions. In this study, contrarily to CRP and α2-globulins, PON1 activity did not provide diagnostic value as a negative acute phase protein in dogs.

Effect of surgeon experience on postoperative plasma cortisol and C-reactive protein concentrations after ovariohysterectomy in the dog: a randomised trial

OBJECTIVE

To determine if postoperative C-reactive protein (CRP) or cortisol concentrations were significantly changed between dogs undergoing ovariohysterectomy by an experienced or inexperienced surgeon. As part of the Charles Sturt University teaching program, 45 bitches from an animal shelter were surgically sterilised between March and October 2010.

METHODS

The dogs were randomly assigned to surgeons, with 37 sterilised by veterinary undergraduates and 8 by experienced surgeons. Blood samples were collected preoperatively and at 2, 4 and 6 h postoperatively. A standard midline ovariohysterectomy was performed and detailed records kept.

RESULTS

The median surgery time for experienced surgeons was 17 min versus 87 min for inexperienced surgeons. Anaesthesia time and blood loss were greater among the inexperienced surgeons. The CRP concentration increased significantly postoperatively for all animals (P < 0.001). Bitches sterilised by inexperienced surgeons had a significantly greater rise in CRP at 4 and 6 h post-surgery (P = 0.046). Serum cortisol concentrations were found to increase significantly over time for all animals (P < 0.001), but were not affected by surgeon experience.

CONCLUSION

The results suggest that inexperienced surgeons affect their patients differently to experienced surgeons, potentially through tissue trauma or anaesthetic duration. The lack of difference in the cortisol concentrations reflects the large number of triggers for cortisol release and, potentially, that there was little difference between the groups in terms of perceived pain in the presence of good analgesia. Serum CRP concentration may be a more sensitive measure than serum cortisol of differences in surgical trauma.

Associations among albuminuria, C-reactive protein concentrations, survival predictor index scores, and survival in 78 critically ill dogs

BACKGROUND

Microalbuminuria and C-reactive protein (CRP) are predictors of morbidity and survival in critically ill human patients.

HYPOTHESIS/OBJECTIVES

To evaluate results of microalbuminuria assays (untimed single-sample urine albumin concentration [U-ALB] and the urine albumin:creatinine ratio [UACR]), serum CRP, and survival predictor index (SPI2) scores as predictors of survival in critically ill dogs.

ANIMALS

Seventy-eight dogs admitted to intensive care units at University of Tennessee (UT) and Colorado State University (CSU).

METHODS

Prospective observational study. Critically ill dogs were eligible for enrollment, unless euthanized because of financial constraints. Samples were collected within 3 hours of admission. Spearman's rank-correlation coefficients were determined for U-ALB, UACR, CRP, and SPI2. U-ALB, UACR, CRP, and SPI2 were assessed for associations with 7- and 30-day survival by Mann-Whitney U-tests and receiver operating characteristic (ROC) curves. P-values < .0125 were considered significant.

RESULTS

UT (n = 49) and CSU (n = 29) patients did not differ significantly. Forty percent (31/78) of dogs died. SPI2 was inversely correlated with U-ALB (r(s) = -0.39, P < .001) and UACR (r(s) = -0.41, P < .001). CRP was not correlated with SPI2 (P = .019), U-ALB (P > .1), or UACR (P > .1). U-ALB and UACR had very high correlation (r(s) = 0.95, P < .001). SPI2, U-ALB, and UACR differed significantly for survivors and nonsurvivors. SPI2, U-ALB, and UACR had areas under the ROC curve (AUC) from 0.68 to 0.74 for survival prediction.

CONCLUSIONS AND CLINICAL IMPORTANCE

Albuminuria and SPI2, but not CRP, are associated with survival in critically ill dogs. Suboptimal AUCs limit the value of microalbuminuria testing for clinical risk assessment. Additional studies are necessary to determine the usefulness of microalbuminuria testing in patient risk stratification for prospective research.

Evaluation of three automated human immunoturbidimetric assays for the detection of C-reactive protein in dogs

C-reactive protein (CRP) is a major, acute-phase protein in dogs; however, there is a need for automated assays to ensure in-time patient monitoring. Three automated immunoturbidimetric assays (Randox, Thermo, and Wako) developed for human beings were evaluated for their ability to detect canine CRP, including method validation, evaluation of diagnostic use, and establishment of exploratory reference intervals. Sera from 36 healthy dogs and 82 diseased dogs were included for method comparison with the enzyme-linked immunosorbent assay (ELISA; Tridelta) serving as the reference method. A nonparametric estimate of the 1-sided 95% reference interval was established (n = 36). Precision study revealed good intra-assay coefficients of variation (CVs) of 1-10%, 0-9%, and 2-13% for the Randox, Thermo, and Wako assays, respectively. Interassay CVs were 18%, 24%, and 19% respectively. Because of a low linear range, the Thermo test was considered unsuitable for use with canine specimens. No significant differences were present between the results obtained with the Randox and Wako assays with CRP concentrations less than 15 mg/l; however, median CRP results differed significantly between the Thermo test and the ELISA (P = 0.03). Bland-Altman analysis detected a proportional bias of 0.28, -0.59, and 0.61 mg/l for the Randox, Thermo, and Wako assays, respectively. For all tests, median CRP values were significantly different between healthy dogs and dogs with neoplasia. The upper limit of the reference intervals were 8.2 and 9.9 mg/l for the Randox and Wako assays, respectively. In contrast to the Thermo test, the Randox and Wako assays were suitable for detection of abnormally high canine CRP concentrations; however, improvement of assay precision and evaluation of accuracy are warranted before their clinical use with canine specimens.

C-reactive protein as a prognostic indicator in dogs with acute abdomen syndrome

The objective of the present study was to measure serum C-reactive protein (CRP) concentrations in 32 dogs with acute abdomen syndrome at presentation and after 48-72 hr. Data were evaluated to determine if there was an association between CRP concentration and outcome, and if CRP concentration correlated with the white blood cell (WBC) count at both time points. An immunoturbidimetric assay for human CRP, previously validated for use in dogs, was used for serum CRP analysis. Increased serum CRP concentrations were found in 21 dogs at presentation. Fifteen of these dogs had declining serum CRP concentrations by 48-72 hr, but 3 of the 15 dogs were later euthanized. Serum CRP concentrations increased by 48-72 hr in 4 dogs. Of the 32 dogs, 4 were dead or were euthanized prior to the 48-72 hr time point. No significant difference between initial CRP concentration and outcome was found (P = 0.054). Initial and 48-72 hr CRP values taken together were significantly different between outcome groups (P < 0.001). Serum CRP concentrations that were elevated at both time points were associated with a poor prognosis. No correlation was found between CRP concentrations and WBC counts at presentation (P = 0.83); however, a significant correlation was noted at 48-72 hr (P = 0.03). Evaluation of sequential CRP concentrations in dogs with acute abdomen syndrome may be helpful in assessing clinical response to treatment and predicting outcome. Also, serum CRP may be better in detecting tissue injury and/or inflammation at presentation than WBC counts in select cases.

Monitoring the response of canine hyperadrenocorticism to trilostane treatment by assessment of acute phase protein concentrations

BACKGROUND

Acute phase proteins (APPS) include haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA). Increased Hp concentrations may be induced by endogenous or exogenous glucocorticoids in dogs.

OBJECTIVES

To assess whether control of hyperadrenocorticism (HAC) affects the concentrations of Hp, CRP, SAA, alkaline phosphatase (ALKP) and cholesterol, to determine whether these analytes can be used to assess control of HAC following trilostane treatment, and whether a combination of these tests offers a valid method of assessing disease control.

METHODS

Hp, CRP, SAA, ALKP and cholesterol were assessed in 11 dogs with spontaneous HAC before and after treatment with trilostane. Adequate control of HAC was defined as post-ACTH cortisol less than 150 nmol/l.

RESULTS

Significant reductions in Hp, ALKP, cholesterol and SAA (P<0.05) but not of CRP were found after control of HAC. Only Hp, cholesterol and ALKP were moderately informative (Se & Sp>0.7) of disease control when compared to adrenocorticotropin or corticotropin (ACTH) stimulation test. SAA and CRP were unhelpful (Se & Sp<0.7). The analysis of the combination of the analytes did not improve the correlation with ACTH stimulation test.

CLINICAL RELEVANCE

Relying on these analytes does not provide additional information over ACTH stimulation test results when assessing control of HAC treated with trilostane.

Acute phase proteins: Biomarkers of infection and inflammation in veterinary medicine

Acute phase proteins (APPs) have been used as biomarkers of inflammation, infection and trauma for decades in human medicine but have been relatively under-utilised in the context of veterinary medicine. However, significant progress has been made in the detection, measurement and application of APPs as biomarkers in both companion and farm animal medicine over recent years. In the dog, C-reactive protein, haptoglobin and serum amyloid A have been identified as significant diagnostic 'markers' of steroid-responsive meningitis-arteritis, while in cats and cattle haptoglobin and alpha(1) acid glycoprotein and haptoglobin and serum amyloid A have proved valuable biomarkers of disease, respectively. In dairy cattle, haptoglobin and a mammary-associated serum amyloid A3 isoform, produced by the inflamed mammary gland during episodes of mastitis, have great potential as biomarkers of this economically important disease. Understanding the use of APP as biomarkers of inflammatory conditions of domestic animals has expanded significantly over recent years, and, with the insights provided by ongoing research, it is likely that these compounds will be increasingly used in the future in the diagnosis and prognosis of both companion and farm animal disease.

Biomarkers in veterinary cancer screening: Applications, limitations and expectations

The identification of biomarkers that distinguish diseased from normal individuals is of intense interest in many health-related fields. Potential applications for biomarkers in veterinary oncology include diagnosis, staging, prognosis and monitoring responses to therapy. By definition, effective biomarkers for cancer screening facilitate disease identification in sub-clinically affected patients and lead to subsequent improvements in clinical outcome. Although the methods and techniques of biomarker discovery and clinical application are translatable from humans to animals, veterinary medicine has lagged behind its human counterpart in several areas. Veterinarians have previously had a flawed understanding of how to use biomarker assays appropriately and have not had the positive influence on product research and development that could advance this field. The controversies, potentials biases, and considerations relative to the clinical application of biomarker assays for cancer screening are discussed in this review.

Serum acute phase protein concentrations in female dogs with mammary tumors

Acute phase proteins (APPs) are proteins whose concentrations in serum change after any inflammatory stimulus or tissue damage. The aim of the current study was to evaluate 3 positive APPs (C-reactive protein, serum amyloid A, and haptoglobin) and 1 negative APP (albumin) in female dogs with mammary neoplasia. Acute phase proteins were studied in 70 female dogs aged 8-12 years in the following groups: healthy (n = 10); mammary tumors in stages I (n = 19), II (n = 5), III (n = 6), IV (n = 5), and V (n = 7); and with mammary neoplasia plus a concomitant disease (n = 18). In animals with mammary neoplasia, significant increases of positive APPs were only detected in those that had metastasis or a neoplasm with a diameter greater than 5 cm and ulceration. Dogs with mammary neoplasia and a concomitant disease also had high C-reactive protein concentrations. Albumin concentration was decreased in animals with metastasis and with a concomitant disease. The results of the present study indicate that the acute phase response could be stimulated in female dogs with mammary gland tumors because of different factors, such as metastasis, large size of the primary mass, and ulceration or secondary inflammation of the neoplasm.

Canine procalcitonin messenger RNA expression

Procalcitonin is considered an acute phase protein used as both a marker of infection and prognosis in human medicine. Canine procalcitonin has been previously sequenced; however, its use as a diagnostic or prognostic tool in dogs has never been assessed. A quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay for canine procalcitonin messenger RNA (mRNA) was developed. Whole blood samples were collected from ill and healthy dogs. RNA was extracted and the real-time PCR was assessed. The patients' diagnoses, complete blood cell count, and differential leukocyte count results were recorded. Based on the diagnosis, dogs were divided into 5 groups: inflammatory, infectious, neoplastic, other diseases, and healthy controls. Procalcitonin mRNA expression and the hematological measures were compared between groups, and their correlations were assessed. Procalcitonin mRNA expression was assessed in 70 dogs, including infectious (17), noninfectious inflammatory (17), neoplastic (18), other diseases (7), and healthy controls (11), and was significantly (P < 0.001) higher in all ill dogs versus controls. Procalcitonin may therefore be considered an acutephase protein in dogs. However, there were no significant differences in procalcitonin mRNA expression between ill dog groups and no correlations between its expression levels and hematological measures. In 5 dogs of all disease categories, procalcitonin mRNA expression was measured twice during the course of disease. The changes in its levels were in agreement with the clinical evaluation of improvement or deterioration, suggesting a possible prognostic value.

Laboratory: Laboratory updates: Acute phase protein tests for diagnosis and monitoring of disease in small animals

In the following paper Rory Bell and David Eckersall give a clinical introduction to the diagnostic use of Acute Phase Protein analysis in small animal medicine. David Eckersall is the leading expert in this field in the world and has presented his research findings widely over the last few years. This included a series of lectures at the American College of Veterinary Pathology meeting in 2006, which was reported in summary in this column (March 2007). The following review is timely and relevant because these tests are now increasingly commercially available and have a significant impact on diagnosis and case management.