Determination of C-reactive protein in serum and plasma from healthy dogs and dogs with pneumonia by ELISA and slide reversed passive latex agglutination test

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.

Signalment and C-reactive protein values in dogs with immune-mediated polyarthritis and steroid responsive meningitis arteritis

Introduction

This retrospective multicentric study aims to evaluate the ability of CRP concentration to differentiate between dogs diagnosed with IMPA and SRMA. C-reactive protein (CRP) is a marker of inflammation widely used in two of the most commonly diagnosed immune-mediated diseases in dogs-Immune-mediated polyarthritis (IMPA) and steroid responsive meningitis arteritis (SRMA).

Materials and methods

Data collected from medical records of 167 client-owned dogs included age, breed, gender, neuter status, body weight, body temperature, CRP concentration, month and season of diagnosis. CRP was measured quantitatively in 142 dogs (84%) and semi-quantitatively in 27 dogs (16%).

Results

SRMA was diagnosed significantly more often in dogs < 12 months old and IMPA in dogs ≥12 months old (P < 0.001). Dogs diagnosed with SRMA had higher CRP concentration than dogs diagnosed with IMPA (P = 0.02). This difference was influenced by the dog's age-when a dog was <12 months old, a higher CRP concentration indicated IMPA (P = 0.02), whereas when a dog was ≥12 months old, a higher CRP concentration indicated SRMA (P = 0.02).

Discussion

CRP concentration as a sole diagnostic modality showed only fair discriminatory potential to differentiate between SRMA and IMPA (area under ROC curve close to 0.7). CRP concentration varied depending on patient age and definitive diagnosis. It may play some role in differentiating between SRMA and IMPA but should not be used as the sole diagnostic modality, given it has been demonstrated to only have fair discriminatory potential.

Serum acute-phase protein concentrations following uncomplicated total hip arthroplasty in dogs

OBJECTIVES

To establish preoperative and postoperative serum C reactive protein (CRP) and serum amyloid A (SAA) levels in dogs undergoing uncomplicated total hip arthroplasty (THA).

STUDY DESIGN

Prospective clinical trial.

ANIMALS

Eighteen client-owned dogs.

METHODS

Dogs undergoing THA were recruited. Serum CRP and SAA levels were measured in all dogs the day prior to surgery, and 3 and 6 months following surgery. All dogs received a physical examination and underwent radiography at each visit, and dogs with complications were excluded from the study. For continuous numeric data, histograms were generated and evaluated for normality. A 1-way repeated measures ANOVA was performed to find differences between time points.

RESULTS

No complications were encountered in any of the recruited dogs. Median age was 30 months (12-66), and the median bodyweight was 27.3 kg (22.3-40.2). Mean CRP concentrations in the preoperative, 3-month, and 6-month periods were 3.8 mg/L ± 4.4, 0.8 mg/L ± 1.9, and 1.4 mg/L ± 1.4, respectively. The mean SAA concentrations in the preoperative, 3-month, and 6-month periods were 13.9 mg/L ± 8.8, 14.1 mg/L ± 12.6, and 18.4 mg/L ± 15.1, respectively. There were no differences for each parameter between time points.

CONCLUSION

C-reactive protein and SAA levels were consistent with levels previously established for noninflammatory and normal conditions in dogs.

CLINICAL SIGNIFICANCE

Postoperative CRP and SAA concentrations were low by 3 months following uncomplicated THA.

The Future of Biomarkers in Veterinary Medicine: Emerging Approaches and Associated Challenges

Simple Summary

In this review we seek to outline the role of new technologies in biomarker discovery, particularly within the veterinary field and with an emphasis on ‘omics’, as well as to examine why many biomarkers-despite much excitement-have not yet made it to clinical practice. Further we emphasise the critical need for close collaboration between clinicians, researchers and funding bodies and the need to set clear goals for biomarker requirements and realistic application in the clinical setting, ensuring that biomarker type, method of detection and clinical utility are compatible, and adequate funding, time and sample size are available for all phases of development.

Abstract

New biomarkers promise to transform veterinary practice through rapid diagnosis of diseases, effective monitoring of animal health and improved welfare and production efficiency. However, the road from biomarker discovery to translation is not always straightforward. This review focuses on molecular biomarkers under development in the veterinary field, introduces the emerging technological approaches transforming this space and the role of ‘omics platforms in novel biomarker discovery. The vast majority of veterinary biomarkers are at preliminary stages of development and not yet ready to be deployed into clinical translation. Hence, we examine the major challenges encountered in the process of biomarker development from discovery, through validation and translation to clinical practice, including the hurdles specific to veterinary practice and to each of the ‘omics platforms–transcriptomics, proteomics, lipidomics and metabolomics. Finally, recommendations are made for the planning and execution of biomarker studies with a view to assisting the success of novel biomarkers in reaching their full potential.

Metabolic variables of obese dogs with insulin resistance supplemented with yeast beta-glucan

Background

Obesity is one of the most common nutritional disorders in dogs and cats and is related to the development metabolic comorbidities. Weight loss is the recommended treatment, but success is difficult due to the poor satiety control. Yeast beta-glucans are known as biological modifiers because of their innumerable functions reported in studies with mice and humans, but only one study with dogs was found. This study aimed to evaluate the effects of a diet supplemented with 0.1% beta-glucan on glucose, lipid homeostasis, inflammatory cytokines and satiety parameters in obese dogs. Fourteen dogs composed three experimental groups: Obese group (OG) with seven dogs with body condition score (BCS) 8 or 9; Lean group (LG) included seven non-obese dogs with a BCS of 5; and Supplemented Obese group (SOG) was the OG dogs after 90 days of consumption of the experimental diet.

Results

Compared to OG, SOG had lower plasma basal glycemic values (p = 0.05) and reduced serum cholesterol and triglyceride levels. TNF-α was lower in SOG than in OG (p = 0.05), and GLP-1 was increased in SOG compared to OG and LG (p = 0.02).

Conclusion

These results are novel and important for recognizing the possibility of using beta-glucan in obesity prevention and treatment.

Serum concentrations of canine pancreatic lipase immunoreactivity and C-reactive protein for monitoring disease progression in dogs with acute pancreatitis

Background

Reliable biomarkers for monitoring disease progression and management in dogs with acute pancreatitis have not been described.

Objective

To determine if serum concentrations of canine pancreatic lipase immunoreactivity (cPLI) and C‐reactive protein (CRP) can be used as biomarkers for disease progression in hospitalized dogs with acute pancreatitis.

Animals

Thirteen hospitalized dogs with acute pancreatitis diagnosed based on clinical signs, serum cPLI concentrations, and imaging findings were enrolled.

Methods

Serum cPLI and CRP concentrations were determined before and then daily during hospital management and 1 week after hospital discharge. Modified canine activity index (MCAI) and canine acute pancreatitis clinical severity index (CAPCSI) scores were calculated daily for each patient while hospitalized.

Results

The MCAI scores (P = .03) but not CAPCSI scores (P = .31) were significantly different between dogs that survived to discharge (n = 11) and those that did not (n = 2). Serum cPLI concentration was positively correlated with MCAI (rho = 0.42; P = .01). Serum CRP concentration also was positively correlated with the MCAI (rho = 0.42, P = .01).

Conclusions

Serum cPLI and possibly CRP could be used as objective biomarkers for clinical changes in hospitalized dogs with acute pancreatitis. Additional studies involving larger numbers of dogs would be warranted to evaluate the broader impact of these findings.

Serum C-reactive protein in dogs with paraplegia secondary to acute intervertebral disc extrusion

BACKGROUND

Apart from the absence of nociception, there is no readily available prognostic test for dogs presenting with paraplegia secondary to acute intervertebral disc extrusion (IVDE).

OBJECTIVE

To assess if serum C-reactive protein (CRP) can predict the postoperative outcome in paraplegic dogs undergoing surgery for IVDE and to assess the association between serum CRP and presence/absence of nociception on admission, and serum CRP and presence/absence of intramedullary changes seen on magnetic resonance imaging (MRI).

ANIMALS

One hundred dogs that underwent surgery at our hospital between 2018 and 2020 because of acute paraplegia secondary to IVDE and in which serum CRP was measured.

METHODS

Retrospective observational cohort study. Dogs were classified as 4 or 5 according to the modified Frankel score (MFS) depending on presence/absence of nociception, respectively. MRI images were reviewed and the T2-weighted hyperintensity: L2 vertebral body length was measured. Postoperative outcome was defined as positive if nociception, ambulation or both returned after decompressive surgery.

RESULTS

The median (95% CI) serum CRP was 4 (4-5) and 6 (4-7) mg/L in MSF4 and MSF5, respectively (P = .03). A weak linear relationship (R²  = 0.049, P = .03) was found between CRP and the T2-weighted hyperintensity: L2 vertebral length. Outcome data was available for 85 dogs: CRP was 4 (4-5) and 5 (4-10) mg/L in positive and negative outcome dogs, respectively (P = .32).

CONCLUSION AND CLINICAL IMPORTANCE

Serum CRP did not predict outcome after surgery in dogs with paraplegia secondary to IVDE.

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.

Development of canine C-reactive protein assays

C-reactive protein (CRP), which is released during tissue damage and inflammation, is a useful nonspecific inflammatory marker in both human and veterinary clinical practice. Veterinarians have often used human CRP assays to analyze samples from canine patients, but cross-reactivities between the species affect assay sensitivity and reliability, leading to inaccurate inflammation assessment. To improve the efficiency of inflammation assessment, we developed a canine CRP detection enzyme-linked immunosorbent assay (ELISA) for quantitative analysis and an immunochromatography assay (ICA) for semiquantitative point-of-care (POC) analysis. The ELISA demonstrated an assay detection limit of 0.5 ng/mL, quantitative linear assay range of 1.6–100 ng/mL, and intra- and inter-assay coefficient of variations of 0.7 to 10.0% and 6.0 to 9.0%, respectively; the recovery rates of samples spiked with purified canine CRP were 105 to 109%, and the parallelism assessments were 82.7 to 104.4%. The correlation between the CRP level results obtained with the ELISA and those of a currently available quantitative POC assay was 0.907 with the regression formula of y = 0.55x + 0.05. In addition, the ICA requires only 5 μL samples and a 10-min assay time, and clearly distinguished positive, weak positive, and negative samples (P < 0.001) at an approximately 5–10 µg/mL cut-off value. The developed canine CRP ELISA and ICA showed reliable assay results and a high correlation with a commercially available POC assay in clinical use. The ICA can be a useful canine CRP screening test for diagnostic purposes in veterinary clinics.

Biomarkers of health and welfare: A One Health perspective from the laboratory side

A biomarker is any measurement reflecting an interaction between a biological system and a potential hazard, which may be chemical, physical, or biological. The One World, One Health concept established that human and animal health and the environmental state are highly interconnected, sharing common aspects that can be applied globally in these three components. In this paper, we review how the concept of One Health can be applied to biomarkers of health and welfare, with a special focus on five points that can be applied to any biomarker when it is expected to be used to evaluate the human, animal or environmental health. Three of these points are: (1) the different biomarkers that can be used, (2) the different sample types where the biomarkers can be analysed, and (3) the main methods that can be used for their measurement. In addition, we will evaluate two key points needed for adequate use of a biomarker in any situation: (4) a proper analytical validation in the sample that it is going to be used, and (5) a correct selection of the biomarker. It is expected that this knowledge will help to have a broader idea about the use of biomarkers of health and welfare and also will contribute to a better and more accurate use of these biomarkers having in mind their One Health perspective.

Calibration of Novel Protein Biomarkers for Veterinary Clinical Pathology: A Call for International Action

Research into the identification and use of protein biomarkers for use in veterinary clinical pathology has produced numerous potential analytes that could become common tests in the future. One problem that has to be overcome in the general acceptance of a novel biomarker is that differing standards for calibration may be developed by individual laboratories or the diagnostic companies that will provide kits for widespread use. This has been apparent in the development of acute phase protein biomarkers such as canine C-reactive protein. In order to overcome this problem an international initiative is required to ensure that assays developed in separate laboratories would have a consistent calibration protocol so that results produced are equivalent. International reference preparations for serum protein analysis for each relevant species should be established for use as primary standard in the calibration of biomarkers for veterinary diagnosis.

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.

Kinetic simulation method of C-reactive protein in beagle dogs during acute inflammation

The half-life ( t1/2) of C-reactive protein (CRP) and its ability to stimulate weak inflammatory responses were investigated in beagle dogs. Four beagle dogs were administered 20 mg/kg indomethacin and blood was collected from the cephalic vein pre-dosing and at 24, 48, 72, 96, 144, 192, 240, 312, and 360 h post-administration. The serum concentrations of CRP were measured by enzyme-linked immunosorbent assay. The serum t1/2 was calculated using the equation 0.693/elimination rate constant. The serum concentration of CRP beyond 192 h post-administration declined to levels in the normal range. The t1/2 was 148.3 h, which is considered to be the essential t1/2 of CRP. The simulation of CRP serum concentrations at arbitrary times using the elimination rate constant obtained in this study became possible.

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.

Elimination Half-Lives of Acute Phase Proteins in Rats and Beagle Dogs During Acute Inflammation

The half-lives of typical acute phase proteins in rats and beagle dogs during acute inflammation were investigated. Acute inflammation was induced by injection of turpentine oil in rats and administration of indomethacin in beagle dogs. Serum concentrations of α2-macroglobulin (α2M) and C-reactive protein (CRP) were measured by enzyme-linked immunosorbent assay and α1-acid glycoprotein (AAG) was measured by single radial immunodiffusion. Half-life was calculated as 0.693/elimination rate constant (K). The mean half-lives in the terminal elimination phase of α2M and AAG were 68.1 and 164.8 h, respectively. The half-life of AAG was significantly longer than that of α2M. Mean half-lives in the terminal elimination phase of CRP and AAG were 161.9 and 304.4 h, respectively. The half-life of AAG was significantly longer than that of CRP in beagle dogs. No significant differences in the half-life of AAG were observed between rats and beagle dogs. Furthermore, serum concentrations in the terminal elimination phase could be simulated with the K data acquired in this study.

Serum and synovial fluid C-reactive protein level variations in dogs with degenerative joint disease and their relationships with physiological parameters

Degenerative joint disease (DJD) is a progressive, chronic joint disease with an inflammatory component promoting an acute phase protein (APP) response. C-reactive protein (CRP) is one of the most important APPs, used as an inflammation marker in human, but not veterinary medicine. The study was developed in a sample of 48 dogs (n = 48) with DJD and aimed to: 1) identify and quantify the synovial fluid CRP (SFCRP) in these specimens using a validated ELISA test for serum CRP (SCRP) detection and quantification; and 2) to study the possible relationship between SCRP and SFCRP levels variations in DJD patients evaluating the influence of some physical parameters such as gender, body weight, pain level, DJD grade, and the physical activity (PA) of the patients. Statistical analysis considered the results significant for p values <0.05. Our study showed that it is possible to detect and quantify SFCRP levels in DJD patients using a previously validated canine SCRP ELISA test, allowing us to point out a preliminary reference value for SFCRP in patients with DJD. Although, individuals with DJD presents SCRP values within the normal reference range and the SFCRP levels were always lower. Obesity, pain, and the DJD grade presented by the patients are conditions which seem to influence the SCRP levels but not the SFCRP.

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.

Inflammatory and oxidative biomarkers of disease severity in dogs with parvoviral enteritis

OBJECTIVES

To study changes in serum C-reactive protein, haptoglobin, ceruloplasmin and albumin concentration, total anti-oxidant capacity and paraoxonase-1 and butyrylcholinesterase activity in dogs with parvoviral enteritis of different degrees of clinical severity.

METHODS

Prospective study of 9 healthy and 43 dogs with parvoviral enteritis that were classified into mildly, moderately and affected groups.

RESULTS

Dogs with parvoviral enteritis had a significant increase in C-reactive protein compared with healthy dogs, with an increase of higher magnitude in animals with more severe clinical signs. All dogs with parvoviral enteritis had a significant increase in haptoglobin concentration compared with healthy dogs, but with no difference according to disease severity. There was a decrease in paraoxonase-1 activity in parvoviral enteritis.

CLINICAL SIGNIFICANCE

Major increases of C-reactive protein concentrations in dogs with parvoviral enteritis are a marker of disease severity. In addition, higher values for anti-oxidants in severe cases compared with mild and moderate cases suggest a possible compensatory anti-oxidant mechanism.

Polydioxanone biodegradable stent placement in a canine urethral model: analysis of inflammatory reaction and biodegradation

PURPOSE

To investigate the inflammatory reaction and perform quantitative analysis of biodegradation after placement of a polydioxanone (PDO) biodegradable stent in a canine urethral model.

MATERIALS AND METHODS

PDO biodegradable stents were placed in the proximal and distal urethra of nine male mongrel dogs. The dogs were euthanized 4 weeks (group A; n = 3), 8 weeks (group B; n = 3), or 12 weeks (group C; n = 3) after stent placement. The luminal diameter of the stent-implanted urethra was assessed by follow-up retrograde urethrography, and histologic findings were obtained after the dogs were killed. Stents were removed after euthanasia, and their surface morphology and molecular weight were evaluated. Hematologic examination was performed to evaluate inflammatory reaction.

RESULTS

Stent placement was technically successful in all dogs. The average luminal diameter gradually decreased. The average number of epithelial layers (2.93 vs 4.42; P < .001), the average thickness of papillary projection (0.80 mm vs 1.28 mm; P < .001), and the average thickness of submucosal fibrosis (0.34 mm vs 0.49 mm ; P < .001) were significantly increased in group B versus group A. There were no significant differences between group B and group C. The average inflammatory cell infiltration did not differ significantly in the three groups. Molecular weight losses were 54% in group A and 84% in group B. In group C, PDO stents were completely decomposed.

CONCLUSIONS

An experimental study in a canine urethral model has demonstrated acceptable inflammatory reaction with gradually increasing granulation tissue but no luminal obstruction within 12 weeks.

Serum C-reactive protein as a diagnostic biomarker in dogs with bacterial respiratory diseases

Background

C‐reactive protein (CRP) is a major acute‐phase protein in dogs. Serum concentrations are low in healthy animals, but increase rapidly after inflammatory stimuli.

Objective

The aim of the study was to investigate CRP concentrations in various respiratory diseases of dogs and to determine if CRP can be used as a biomarker in the diagnosis of bacterial respiratory diseases.

Animals

A total of 106 privately owned dogs with respiratory diseases (17 with bacterial tracheobronchitis [BTB], 20 with chronic bronchitis [CB], 20 with eosinophilic bronchopneumopathy [EBP], 12 with canine idiopathic pulmonary fibrosis [CIPF], 15 with cardiogenic pulmonary edema [CPE], and 22 with bacterial pneumonia [BP]) and 72 healthy controls.

Methods

The study was conducted as a prospective cross‐sectional observational study. CRP was measured in serum samples. Diagnosis was confirmed by clinical and laboratory findings, diagnostic imaging, and selected diagnostic methods such as cytological and microbiological analysis of respiratory samples, echocardiography, and histopathology.

Results

Dogs with BP had significantly higher CRP concentrations (median, 121 mg/L; interquartile range, 68–178 mg/L) than dogs with BTB (23, 15–38, P = .0003), CB (13, 8–14, P < .0001), EBP (5, 5–15, P < .0001), CIPF (17, 10–20, P < .0001), or CPE (19, 13–32, P < .0001) and healthy controls (14, 8–20, P < .0001). Dogs with BTB had significantly higher CRP concentrations than dogs with CB (P = .001) or EBP (P < .0001) and healthy controls (P = .029).

Conclusion and Clinical Importance

These results indicate that CRP has potential for use as an additional biomarker, especially in the diagnostics of BP.

Oral Recombinant Feline Interferon-Omega as an alternative immune modulation therapy in FIV positive cats: clinical and laboratory evaluation

Recombinant-Feline Interferon-Omega (rFeIFN-ω) is an immune-modulator licensed for use subcutaneously in Feline Immunodeficiency virus (FIV) therapy. Despite oral protocols have been suggested, little is known about such use in FIV-infected cats. This study aimed to evaluate the clinical improvement, laboratory findings, concurrent viral excretion and acute phase proteins (APPs) in naturally FIV-infected cats under oral rFeIFN-ω therapy (0.1 MU/cat rFeIFN-ω PO, SID, 90 days). 11 FIV-positive cats were treated with oral rFeIFN-ω (PO Group). Results were compared to previous data from 7 FIV-positive cats treated with the subcutaneous licensed protocol (SC Group). Initial clinical scores were similar in both groups. Independently of the protocol, rFeIFN-ω induced a significant clinical improvement of treated cats. Concurrent viral excretion and APP's variation were not significant in the PO Group. Oral rFeIFN-ω can be an effective alternative therapy for FIV-infected cats, being also an option for treatment follow-up in cats submitted to the licensed protocol.

Serum thymidine kinase 1 and C-reactive protein as biomarkers for screening clinically healthy dogs for occult disease

Thymidine kinase (TK1) is a biomarker that correlates well with diagnosis and prognosis in certain canine cancers. Canine C-reactive protein (cCRP) is a widely accepted marker of inflammation correlated with increased risk and severity of various diseases. We evaluated serum TK1 and cCRP concentrations in apparently healthy dogs (n = 360). All dogs were followed up for a minimum of 6 months by health questionnaire. All dogs with cancer were identified using a proprietary dual-biomarker algorithm [termed Neoplasia Index (NI)]. Specificity of positive NI is 0.91 and high positive is 0.98. All-cause mortality was 20% in dogs with elevated cCRP and 3% in dogs with low cCRP. The performance of serum TK1 and cCRP as tools for screening for occult cancer is improved when evaluated together. Serum TK1 and cCRP (unified in the NI) are useful in the screening of occult canine cancer. cCRP is useful in screening for other serious diseases.

Preparation of a portable point-of-care in vitro diagnostic system, for quantification of canine C-reactive protein, based on a magnetic two-site immunoassay

In this study, characterization of the binding kinetics and optimization of a magnetic permeability based point-of-care (POC) immunoassay system for quantification of canine C-reactive protein (cCRP) is described. The reagent is based on a two-site heterogeneous immunoassay system utilizing conjugated superparamagnetic nanoparticles (SPION) and silica particles, both particles carrying covalently linked antibodies directed to the cCRP analyte. Detection is carried out using a magnetic permeability-based small instrument, adjusted in order to apply it in a POC setting near the patients. The kinetic parameters are characterized and applied in the final design of the assay system. In the cCRP system studied, 90% of the binding between immobilized solid-phase silica antibody and cCRP is complete after only 15 s, and 30 s for the binding between the antibody on the SPION and the bound cCRP on the silica particle. Additionally, the binding rate constants are determined to be 149 and 30 M(-1)s(-1), respectively. The analytical sensitivity, clinical sensitivity, and imprecision verifies the clinical usefulness of the system. Also, quantification of cCRP, using the system described, in dog clinical samples from mixed breeds shows a high correlation to a commercially available comparative cCRP ELISA system (y = 0.98 × +3.2, R(2) = 0.98, n = 47). The immunoassay system described can thus provide the veterinarian a valuable tool for rapid diagnosis and monitoring of inflammatory diseases in dogs in a setting near the patients.

Canine serum amyloid A (SAA) measured by automated latex agglutination turbidimetry is useful for routine sensitive and specific detection of systemic inflammation in a general clinical setting

Canine serum amyloid A (SAA) is a useful diagnostic marker of systemic inflammation. A latex agglutination turbidimetric immunoassay (LAT) was validated for automated measurements. The aim of the study was to evaluate the clinical applicability of SAA measured by the LAT. SAA was measured in 7 groups of dogs with and without systemic inflammation (n=247). Overlap performance was investigated. Diagnostic performance was compared to body temperature and leukocyte markers. Clinical decision limits for SAA were estimated. In dogs with neurological, neoplastic or gastrointestinal disorders (n=143), it was investigated whether a higher proportion of SAA positive dogs could be detected in cases of complications with risk of systemic inflammation. Significantly higher concentrations of SAA were measured in dogs with (range [48.75; 5,032 mg/l]), compared to dogs without systemic inflammation [0; 56.4 mg/l]. SAA was a more sensitive and specific marker of systemic inflammation (area under the receiver-operating characteristic curve (AUC) 1.00), compared to body temperature (0.6) and segmented neutrophils (best performing leukocyte marker, 0.84). A clinical decision limit of 56.4 mg/l was established giving close to perfect discrimination between dogs with and without systemic inflammation. Higher proportions of SAA-positive dogs were observed in dogs with neurological, neoplastic and gastrointestinal disorders with complications known to increase risk of systemic inflammation, compared to uncomplicated cases. The automated LAT makes SAA applicable as a relevant diagnostic marker of systemic inflammation in dogs for routine random-access real-time use in a general clinical setting.

Serum C-reactive protein concentrations in healthy Miniature Schnauzer dogs

BACKGROUND

C-reactive protein (CRP) is a sensitive marker for inflammation in people and dogs. In people, an association between CRP concentration and atherosclerosis has been reported. Atherosclerosis is rare in dogs, but the Miniature Schnauzer breed may be at increased risk for developing this vascular disease. It is not known if CRP concentrations in Miniature Schnauzer dogs differ from those in other dog breeds.

OBJECTIVES

Our objectives were to validate an automated human CRP assay for measuring CRP in dogs and compare CRP concentrations in healthy Miniature Schnauzer dogs with those in non-Miniature Schnauzer breeds.

METHODS

Sera from 37 non-Miniature Schnauzer dogs with inflammatory disease were pooled and used to validate a human CRP immunoturbidimetric assay for measuring canine CRP. Blood was collected from 20 healthy Miniature Schnauzer dogs and 41 healthy dogs of other breeds. Median serum CRP concentration of healthy Miniature Schnauzer dogs was compared with that of healthy non-Miniature Schnauzer dogs.

RESULTS

The human CRP assay measured CRP reliably with linearity between 0 and 20 mg/L. CRP concentration for healthy Miniature Schnauzer dogs (median 4.0 mg/L, minimum-maximum 0-18.2 mg/L) was significantly higher than for the healthy non-Miniature Schnauzer dogs (median 0.1 mg/L, minimum-maximum 0-10.7 mg/L); 17 of the 20 Miniature Schnauzer dogs had values that overlapped with those of the non-Miniature Schnauzer dogs.

CONCLUSIONS

Median CRP concentration of Miniature Schnauzer dogs was slightly higher than that of other breeds of dogs. A relationship between higher CRP concentration in Miniature Schnauzer dogs and idiopathic hyperlipidemia, pancreatitis, and possible increased risk for atherosclerosis remains to be determined.

Acute phase protein concentrations in dogs with nasal disease

The concentrations of C-reactive protein (CRP), serum amyloid A, haptoglobin (Hp) and α(1)-acid glycoprotein were measured in dogs with clinical signs of nasal disease and compared with those of healthy dogs in order to determine the expression of these proteins in cases of canine nasal disease. A significant difference (P<0.001) between the symptomatic group and the control group was found for both CRP and Hp. Among the animals with nasal disease, a significant intergroup difference (P<0.05) was found in the expression of Hp between dogs with aspergillosis and those with chronic rhinitis.

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.

Canine serum C-reactive protein detected by means of a near-patient test for human C-reactive protein

OBJECTIVES

The aim of the study was to evaluate the reliability of a rapid human C-reactive protein near-patient slide reversed passive latex agglutination test (Randox) for the semi-quantitative determination of canine serum C-reactive protein.

METHODS

The concentration of C-reactive protein was determined in 244 canine serum samples by an established automated immunoturbidimetric method and in various predilutions by a commercially available reversed passive latex agglutination test for human C-reactive protein. The results were compared to assess if the reversed passive latex agglutination test reflected the results of the established method with special emphasis on the reversed passive latex agglutination test's ability to identify samples characterised as positive or negative by the established method.

RESULTS

The reversed passive latex agglutination test reflected the C-reactive protein concentration in canine serum samples at all the tested predilutions (undiluted, 1:4, 1:8 and 1:16). When applying a predilution of 1:8, the positive and negative analytical predictive values for discriminating between positive and negative samples (according to the established quantitative method) were high (0.94 [0.82 to 0.99] and 0.97 [0.93 to 0.99], respectively).

CLINICAL SIGNIFICANCE

In conclusion, this near-patient test was able to reflect the serum C-reactive protein concentration in canine samples in a reliable and clinically useful manner and could be applicable for general practice for evaluating C-reactive protein levels in canine serum.

Lung inflammatory responses

Inflammation is an important manifestation of respiratory disease in domestic animals. The respiratory system is mucosal in nature and has specific defense mechanisms used to control invasion by microbes and environmental elements. Inflammation can be beneficial or detrimental to the host. This article broadly discusses the primary mediators and mechanisms of inflammation within the respiratory tract of domestic animals. The role of cells, chemokines, cytokines and mediators in both acute and chronic inflammation are addressed. The pathogenesis of the initial insult determines the type of inflammation that will be induced, whether it is acute, chronic or allergic in origin. Maintenance of the microenvironment of cytokines and chemokines is critical for pulmonary homeostasis. Uncontrolled inflammation in the respiratory tract can be life threatening to the animal. The understanding of the mechanisms of inflammation, whether due to microbes or through inappropriate immune activation such as those occurring with allergies, is required to develop successful intervention strategies and control respiratory disease in animals.

Analytical and Clinical Validation of a Time-resolved Immunofluorometric Assay (TR-IFMA) for Canine C-reactive Protein in Serum

A time-resolved immunofluorometric assay (TR-IFMA) was developed for the determination of C-reactive protein (CRP) in canine serum. CRP was isolated from canine acute-phase serum by affinity chromatography on agarose coupled with phosphorylethanolamine. This isolated dog CRP was used as standard to calibrate the assay. Intra-assay and inter-assay coefficients of variation were in the ranges 5.3-7.1% and 4.8-13.3%, respectively. Accuracy, evaluated by adding 2 and 10 microg/ml of CRP to serum samples, provided recoveries of 99.9% and 106.8%. High correlation was found between CRP measurements by TR-IFMA and a by commercial enzyme-linked immunosorbent assay (R2 = 0.98). The limit of detection for the TR-IFMA method was 0.000067 microg/ml and the measurement of CRP in serial dilutions of acute-phase dog sera generated curves with the same slope as the one constructed with purified CRP. The TR-IFMA provides a precise, accurate and highly sensitive assay for CRP determination in dog samples. CRP levels in dogs with different diseases ranged between 10.2 and 210.7 microg/ml and were significantly higher than those observed in healthy dogs (< 7.1 microg/ml).

Effect of carprofen, etodolac, meloxicam, or butorphanol in dogs with induced acute synovitis

OBJECTIVE

To compare the analgesic and anti-inflammatory effect of single doses of carprofen, etodolac, meloxicam, and butorphanol in dogs with induced acute synovitis (acute pain model) via kinetic gait analysis and orthopedic evaluation and examine measurement of serum C-reactive protein (CRP) concentration as an indicator of treatment efficacy.

ANIMALS

12 Beagles and 6 additional Beagles that were used only in serum CRP analyses.

PROCEDURE

Acute synovitis was induced in right stifle joints of dogs via intra-articular injection of monosodium urate solution. Treatments included butorphanol (0.2 mg/kg, i.v.), carprofen (4 mg/kg, PO), etodolac (17 mg/kg, PO), or meloxicam (0.2 mg/kg, PO); control dogs received no treatment. The procedure was repeated (3-week intervals) until all dogs received all treatments including control treatment. Lameness was assessed on a biomechanical force platform and via orthopedic evaluations of the stifle joints; blood was collected to monitor serum CRP concentration.

RESULTS

Compared with control dogs, treated dogs had significantly different vertical ground reaction forces and weight-bearing scores. Greatest improvement in lameness was observed in carprofen-treated dogs. Etodolac had the fastest onset of action. Compared with butorphanol treatment, only carprofen and etodolac were associated with significantly lower pain scores. An increase in serum CRP concentration was detected after intra-articular injection in all dogs; this change was similar among groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Carprofen, etodolac, and meloxicam had greater efficacy than butorphanol in relief of acute pain. Carprofen was most effective overall. In this acute pain model, serum CRP analysis was not useful to assess drug efficacy.

Evaluation of a commercially available human C-reactive protein (CRP) turbidometric immunoassay for determination of canine serum CRP concentration

BACKGROUND

Serum C-reactive protein (CRP) is an acute phase marker in dogs that is useful for the diagnosis and monitoring of inflammatory disease. Rapid, reliable, and automated assays are preferable for routine evaluation of canine serum CRP concentration.

OBJECTIVE

The aim of this study was to evaluate whether canine serum CRP concentration could be measured reliably using an automated turbidometric immunoassay (TIA) designed for use with human serum.

METHODS

A commercially available TIA for human serum CRP (Bayer, Newbury, UK) was used to measure canine serum CRP concentration. Cross-reactivity of antigen was evaluated by the Ouchterlony procedure. Intra- and interassay imprecision was investigated by multiple measurements on canine serum samples and serum pools, respectively. Assay inaccuracy was investigated by linearity under dilution and comparison of methodologies (canine CRP ELISA, Tridelta Development Ltd, Kildare, UK). Then the assay was applied to serum samples from 14 clinically healthy dogs, 11 dogs with neoplasia, 13 with infections, 8 with endocrine or metabolic diseases, and 10 with miscellaneous diseases.

RESULTS

Cross-reactivity between canine serum CRP and the anti-human CRP antibody was found. Intra- and interassay imprecision ranged from 5.2% to 10.8% and 3.0% to 10.2%, respectively. Serum CRP concentration was measured in a linear and proportional manner. There was no significant disagreement and there was linear correlation of the results in the comparison of methodologies, except for a slight proportional discrepancy at low CRP concentrations (<10 microg/mL). Dogs with infections had a significantly higher concentration of serum CRP than did all other dogs, and dogs with neoplasia had a significantly higher concentration of serum CRP than did clinically healthy dogs.

CONCLUSIONS

Canine serum CRP concentration can be measured reliably using the commercially available TIA designed for human CRP.

Evaluation of a commercially available enzyme-linked immunosorbent assay (ELISA) for the determination of C-reactive protein in canine serum

The purpose of this study was to evaluate a commercially available enzyme-linked immunosorbent assay for determination of canine serum C-reactive protein (CRP). The concentration of CRP could be determined accurately and the intra- and inter-assay coefficients of variation were in the range of 6.9-10.1 and 7.5-29.0%, respectively. This level of imprecision between runs is usually considered unacceptable for diagnostic purposes, but the overall results indicated that the assay was useful in differentiating dogs suffering from infections, from dogs suffering from various other diseases (neoplastic diseases, endocrine/metabolic disorders), and healthy dogs. The assay was also able to detect dynamic changes of CRP during development and after cessation of spontaneous occurring inflammatory stimuli in two clinical cases.

Determination of Serum C-Reactive Protein (CRP) in Healthy Beagle Dogs of Various Ages and Pregnant Beagle Dogs

Serum C-reactive protein (CRP) concentrations in healthy beagle dogs of various ages and in pregnant beagles were measured by enzyme-linked immunosorbent assay (ELISA). Serum CRP concentrations were 1.5-16.0 microg/ml (mean 7.9 +/- 3.4 microg/ml) in male, and 1.8-18.9 microg/ml (mean 8.3 +/- 4.0 microg/ml) in female dogs. No significant sex-related differences were observed in the values. Further, there were no significant age-related differences either. Serum CRP concentrations increased during pregnancy. The concentration of serum CRP in pregnant dogs peaked at 70.2-90.4 microg/ml (mean 77.5 +/- 7.1 microg/ml) 30 or 45 days after ovulation, demonstrating two characteristic features of CRP concentration change in pregnant dogs.

Physiological levels of C-reactive protein in normal canine sera

This study was undertaken to investigate whether the level of C-reactive protein (CRP) in the serum of dogs undergoes physiological variation, using 10 normal Beagle dogs (5 males and 5 females), 1-2 years old, maintained in a healthy condition in a controlled environment. The CRP concentration in the sera collected seven times each day at intervals of approximately 3 h ranged from 0.8 to 16.4 micrograms/ml (mean 5.06 +/- 3.60) in one experiment and from 0.8 to 14.0 micrograms/ml (mean 4.50 +/- 2.80) in a second experiment. On examining the 24-h variations in the concentration of CRP in serum, neither consistent changes nor a definite pattern of circadian rhythm was detected. During 28 days observation, only very slight changes, which seemed attributable to analytical errors, were seen in any of the dogs, except one. The concentration of CRP in the serum during the 28 days ranged from 0.8 to 22.6 micrograms/ml (mean 3.65 +/- 1.40). The concentrations underwent no significant variations in individual dogs, but significant differences were found between the dogs (p < 0.01).

Harbor seal (Phoca vitulina) C-reactive protein (C-RP): purification, characterization of specific monoclonal antibodies and development of an immuno-assay to measure serum C-RP concentrations

C-reactive protein (C-RP) was purified from harbor seal (Phoca vitulina) serum by calcium dependant phosphoryl-choline and protein A affinity chromatography. Polyacrylamide gel electrophoresis under reducing conditions revealed a single protein moiety with a molecular weight of approximately 25 kDa. An internal peptide derived from this purified protein was subjected to N-terminal amino acid sequencing. A high amino acid sequence similarity was obtained with other published mammalian C-RP molecules confirming that the purified protein was a C-RP homologue. Eight specific monoclonal antibodies (P13, P51, P87, P101, P106, P130, P157 and P219) were raised against this purified protein. All 8 monoclonal antibodies immunoblotted with the 25 kDa C-RP subunit under reducing conditions. A competitive immunoassay was developed identifying elevated C-RP concentrations in harbor seal serum samples with clinical evidence of inflammatory disease. Application of this immunoassay for the measurement C-RP may provide valuable information for the clinical assessment of harbor seal health.

Quantitative capillary reversed passive latex agglutination test for C-reactive protein (CRP) in the dog

A capillary reversed passive latex agglutination test (capillary RPLA) was developed which allows quantification of serum C-reactive protein (CRP) within approximately 15 min. The logarithmic regression line (calibration curve) obtained after measuring each CRP concentration three times in twofold dilutions of a standard canine serum containing 222 micrograms/ml of CRP was y = 6.394 + 0.030x (r = 0.995). Capillary RPLA permitted quantification of CRP in the range 6.9-222 micrograms/ml. The coefficients of variation ranged from 10.28% to 12.40%. The recovery rates (percentage recovery) of CRP by capillary RPLA were within the range 87% to 106%. On measuring the CRP concentrations in sera from 78 dogs by capillary RPLA, single radial immunodiffusion (SRID) and enzyme-linked immunosorbent assay (ELISA), close correlations were demonstrated between SRID and capillary RPLA (y = 7.250 + 1.109x, r = 0.978), between SRID and ELISA (y = 3.042 + 1.059x, r = 0.967), and between capillary RPLA and ELISA (y = 1.778 + 0.929x, r = 0.962). Capillary RPLA may be considered useful as a routine biochemical technique for measurement of serum CRP concentration in the dog.

Serum C-reactive protein and immune responses in dogs inoculated with Bordetella bronchiseptica (phase I cells)

Eight Beagle dogs were inoculated intrabronchially with 5 x 10(9) live, avirulent cells of Bordetella bronchiseptica L-414 strain (phase I cells) (B. bronchiseptica) to investigate the serum levels of their C-reactive protein, the white blood cell counts, the antibody responses to B. bronchiseptica in the sera and tracheal secretions, and the effects of prednisolone given to four of the dogs on C-reactive protein (CRP), white blood cells (WBC) and immune responses. In two Beagle dogs inoculated intrabronchially with sterile physiological saline, the concentrations of CRP and the WBC counts did not increase. CRP was markedly increased one day after inoculation in the dogs inoculated with B. bronchiseptica to 385.0-720.0 micrograms/ml (mean 498 +/- 132 micrograms/ml) in the group given the B. bronchiseptica inoculation only, and to 372.0-649.0 micrograms/ml (mean 551 +/- 106 micrograms/ml) in the group treated with prednisolone following inoculation of B. bronchiseptica, as determined by an enzyme-linked immunosorbent assay (ELISA). The CRP levels were 23-95 times the pre-inoculation values, which indicated that prednisolone had no effect on the production of CRP. In the prednisolone-treated group, the WBC count increased and stayed at an increased level for approximately 12 days. An indirect fluorescent antibody test led to the detection of anti-B. bronchiseptica IgM and IgG antibodies in the sera from 5 days after B. bronchiseptica inoculation and S-IgA and IgG anti-B. bronchiseptica antibodies in the tracheal secretions on the day after the challenge exposure to B. bronchiseptica. The increase in CRP after challenge exposure to B. bronchiseptica was significantly (p < 0.05) smaller than that found after the first inoculation of B. bronchiseptica.