Changes in biomarkers of the redox status in whole blood and red blood cell lysates in canine hypothyroidism

Hypothyroidism is the most commonly diagnosed endocrine disease in dogs. The objective of this study was to evaluate the changes in the redox status in canine hypothyroidism using whole blood (WB) and red blood cell (RBCs) lysates. For this purpose, a panel of five antioxidants and five oxidants biomarkers was measured in WB and RBCs lysates of 30 dogs with hypothyroidism, 26 dogs with non-thyroidal illnesses and 15 healthy dogs. The antioxidants measured were cupric reducing antioxidant capacity (CUPRAC), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC), thiol and paraoxonase type-1 (PON-1). Oxidants measured include the total oxidant status (TOS), peroxide-activity (POX-Act), reactive oxygen-derived metabolites (d-ROMs), advanced oxidation protein products (AOPP) and thiobarbituric acid reactive substances (TBARS). WB showed a significant decrease of the antioxidants CUPRAC, TEAC and thiol, and also an increase in TBARS and a decrease in AOPP in dogs with hypothyroidism compared to healthy dogs. Meanwhile, RBCs lysates showed a significant increase in FRAP and PON-1 in dogs with hypothyroidism. The changes in the redox biomarkers in this study show that WB in canine hypothyroidism had a higher number of changes in biomarkers of the redox status than RBCs lysates, making it a promising sample type for the evaluation of the redox status in this disease. In addition, WB is easier and simpler to process than RBCs lysates and unlike serum, it does not have any hemolysis interference.

Association between Eosinophil Count and Cortisol Concentrations in Equids Admitted in the Emergency Unit with Abdominal Pain

Stress leukogram includes eosinopenia as one of its main markers (neutrophilia, eosinopenia, lymphopenia, and mild monocytosis). Cortisol is the main stress biomarker, which is also strongly correlated with the severity of gastrointestinal diseases. This study aimed to determine the relationship between salivary cortisol and the eosinophil cell count (EC) in equids with abdominal pain. To do this, 39 horses with abdominal pain referred to an emergency service were included. All samples were taken on admission, and several parameters and clinical data were included. Equids were classified according to the outcome as survivors and non-survivors. Non-surviving equids presented higher salivary cortisol concentrations (Non-Survivors: 1.580 ± 0.816 µg/dL; Survivors 0.988 ± 0.653 µg/dL; p < 0.05) and lower EC (Non-Survivors: 0.0000 × 103/µL (0.000/0.0075); Survivors: 0.0450 × 103/µL (0.010/0.1825); p < 0.01). In addition, the relationship between salivary cortisol concentration, EC, and the WBC was determined. Only a strong correlation (negative) was observed between cortisol and EC (r = -0.523, p < 0.01). Since cortisol is not an analyte that can be measured routinely in clinical settings such as emergencies, the EC could be a good alternative. While the results are promising, further studies are needed before EC can be used confidently in routine practice to predict survival in cases of abdominal pain.

Changes of the salivary and serum proteome in canine hypothyroidism

In this study, changes in salivary and serum proteome of dogs with hypothyroidism were studied using tandem mass tags (TMT) labelling and liquid chromatography-mass spectrometry (LC-MS/MS). Saliva and serum proteome from 10 dogs with hypothyroidism were compared with 10 healthy dogs. In saliva, a total of seven proteins showed significant changes between the two groups, being six downregulated and one upregulated, meanwhile, in serum, a total of six proteins showed significant changes, being five downregulated and one upregulated. The altered proteins reflected metabolic and immunologic changes, as well as, skin and coagulation alterations, and these proteins were not affected by gender. One of the proteins that were downregulated in saliva, lactate dehydrognease (LDH), was measured by a spectrophotometric assay in saliva samples from 42 dogs with hypothyroidism, 42 dogs with non-thyroid diseases and 46 healthy dogs. The activity of LDH was lower in the saliva of hypothyroid dogs when compared to non-thyroid diseased dogs and healthy controls. This study indicates that canine hypothyroidism can produce changes in the proteome of saliva and serum. These two sample types showed different variations in their proteins reflecting physiopathological changes that occur in this disease, mainly related to the immune system, metabolism, skin and coagulation. In addition, some of the proteins identified in this study, specially LDH in saliva, should be further explored as potential biomarkers of canine hypothyroidism.

Validation of assays for measurement of oxidant compounds in saliva of pigs: Thiobarbituric acid reactive substances (TBARS), carbonyl, and reactive oxygen species (ROS)

Thiobarbituric acid reactive substances (TBARS), carbonyls and reactive oxygen species (ROS) are oxidant compounds that can provide useful information on the oxidative status. Pigs can be affected by oxidative stress in different situations including physiological conditions such as lactation and also in different diseases, and the measurement of these three analytes in saliva could be potentially useful as biomarkers of the redox status in this species. Assays for the measurement of TBARS and carbonyls by spectrophotometry and ROS by luminol-based chemiluminescence in pigs' saliva were analytically validated and were applied in saliva of pigs after an in vitro incubation with different doses of ascorbic acid (AA). All the assays showed a satisfactory analytical precision and accuracy. The 240 h-incubation of saliva samples with 60 mM of AA induced to an increased TBARS and carbonyls production. TBARS, carbonyls and ROS can be estimated in saliva of pigs by the assays validated in this report. In addition, these assays can detect changes in the concentration of these analytes associated to incubation of saliva samples with AA.

Measurement of haptoglobin in saliva of cows: Validation of an assay and a pilot study of its potential application

In recent years, the use of saliva as a matrix for the measurement of biomarkers of health and welfare is gaining importance due to its non-invasive collection. Haptoglobin (Hp) is an acute-phase protein involved in the inflammatory response and changes in its concentration can provide information about the health status of the animals. This study aimed to develop and validate an assay based on luminescent amplification (AlphaLISA technology) for the measurement of Hp in bovine saliva and to study the possible changes in different inflammatory situations such as peripartum period and lameness. The assay proved to be accurate, reliable, and sensitive for the measurement of Hp in cow saliva (coefficient of variation (CV) 7.57%; coefficient of determination (R²) 0.992; recovery test 105.15%; lower limit of quantification (LLQ) 7.9 ng/ml). Significant differences were observed between Hp levels in saliva of cows before (13 days before) and after (7 and 20 days after) calving and at the moment of calving (p < 0.0001), and between lame and healthy cows (p < 0.008). In conclusion, this assay can detect Hp in a precise, sensitive, and accurate way in saliva of cows. Future studies with a larger population and different disease conditions should be conducted to determine the potential of Hp as an inflammatory biomarker in cow saliva.

Changes in salivary analytes in cows due to the in vitro presence of feed

BACKGROUND

The effect in a sialochemistry profile of the presence of usually available feed in dairy cows was evaluated by an in vitro experiment. For this purpose, a pooled clean saliva from five healthy dairy cows was incubated five times with a standard feed based on a total mixed ration (F), wheat hay (H), and grass (G). The salivary panel was integrated by biomarkers of stress (cortisol -sCor-, salivary alpha-amylase -sAA-, butyrylcholinesterase -BChE-, total esterase -TEA-, and lipase -Lip-), immunity (adenosine deaminase -ADA-), oxidative status (Trolox equivalent antioxidant capacity -TEAC-, the ferric reducing ability of saliva -FRAS-, the cupric reducing antioxidant capacity -CUPRAC-, uric acid, and advanced oxidation protein products -AOPP-), and enzymes, proteins, and minerals of general metabolism and markers of liver, muscle, and renal damage (aspartate aminotransferase -AST-, alanine aminotransferase -ALP-, γ-glutamyl transferase -gGT-, lactate dehydrogenase -LDH-, creatine kinase -CK-, creatinine, urea, triglycerides, glucose, lactate, total protein, phosphorus, and total calcium).

RESULTS

Most of the evaluated analytes showed a coefficient of variations (CV) higher than 15% and/or significant changes compared with the clean saliva when feed was present. Some analytes, such as the oxidative status biomarkers (CV > 80%), AST (CV > 60%), or glucose (CV > 100%), showed significant changes with all the feed types tested. Others showed significant differences only with certain types of feed, such as LDH with F (CV > 60%) or triglycerides with F (CV > 100%) and H (CV > 95%). However, sCor or gGT remained unchanged (CV < 15%, P > 0.05) in all the treatments.

CONCLUSIONS

The presence of feed can produce changes in most of the analytes measured in cows' saliva, being of high importance to consider this factor when saliva is used as a sample to avoid errors in the interpretation of the results.

Basics for the potential use of saliva to evaluate stress, inflammation, immune system, and redox homeostasis in pigs

The use of saliva as a biological sample has many advantages, being especially relevant in pigs where the blood collection is highly stressful and painful, both for the animal and the staff in charge of the sampling. Currently one of the main uses of saliva is for diagnosis and detection of infectious diseases, but the saliva can also be used to measure biomarkers that can provide information of stress, inflammation, immune response and redox homeostasis. This review will be focused on the analytes that can be used for such evaluations. Emphasis will be given in providing data of practical use about their physiological basis, how they can be measured, and their interpretation. In addition, some general rules regarding sampling and saliva storage are provided and the concept of sialochemistry will be addressed. There is still a need for more data and knowledge for most of these biomarkers to optimize their use, application, and interpretation. However, this review provides updated data to illustrate that besides the detection of pathogens in saliva, additional interesting applicative information regarding pigs´ welfare and health can be obtained from this fluid. Information that can potentially be applied to other animal species as well as to humans.

Changes in saliva proteins in cows with mastitis: A proteomic approach

This study aimed to evaluate the possible saliva proteome changes in cows with mastitis using a Tandem Mass Tags (TMT) proteomics approach. For this purpose, the salivary proteomes from healthy cows and cows with mastitis were analysed, and their serum proteomes were also studied for comparative purposes. A total of eight saliva and serum paired samples for each group were used for the proteomic study, and eight additional samples for each group were analysed in the analytical and overlap performance studies. In saliva samples, 2192 proteins were identified, being sixty-three differentially modulated in mastitis. In serum, 1299 proteins were identified, being twenty-nine differentially modulated in mastitis. Gamma glutamyl transferase (γGT) in saliva and serum amyloid A (SAA) were validated by commercially available automated assays. In conclusion, there are changes in protein expression and metabolic pathways in saliva and serum proteomes of cows with mastitis, showing different response patterns but complementary information.

Changes in saliva biomarkers during a standardized increasing intensity field exercise test in endurance horses

Salivary biomarkers could be useful to evaluate stress, fitness level, and skeletal muscle damage associated to exercise in horses in an easy and non-painful way. Therefore, this study aims to evaluate if cortisol in saliva (sCor), salivary alpha-amylase (sAMY) and butyrylcholinesterase (sBChE) and lactate (sLA) and creatine kinase (sCK) in saliva of horses can show changes during a standardized exercise test, and if they are related to heart rate variability (HRV) parameters related to sympathetic and parasympathetic tone, fitness level or skeletal muscle damage. For this purpose, ten endurance horses were submitted to a standardized exercise test in field conditions. Saliva and blood were obtained at basal time (TB), after the seven bouts of velocity (T + 01 to T + 07), and 5, 15, 30, and 45 min later (T + 5, T + 15, T + 30, and T + 45). Five endurance horses in resting condition (control group) were also enrolled. HRV and fitness level parameters, and plasma CK as a marker of muscle damage were also evaluated. Salivaryalpha-amylase increased at T + 30 (P = 0.03), sBChE at T + 5 (P = 008), and sCK at T + 07 (P = 0.009) after the exercise test, with significant differences between the exercise and control groups' results. The sCor did not show significant changes during the exercise test in the exercise group but higher concentration compared to the control horses (P < 0.001) were observed. sCor, sAMY, sBChE, and sCK showed a positive correlation (r values between 0.47 and 0.64) with the sympathetic tone and a negative correlation (r values between -0.37 and -0.56) with the parasympathetic tone. In conclusion, sAMY, sBChE, and sCK showed significant increases in ten endurance horses after an increasing intensity velocity exercise. Values of sCor, sAMY, sBChE, and sCK were associated with HRV, which is used to evaluate stress, and therefore, they could be potentially used to assess the exercise-related stress after a physical effort.

Effect of reduction and alkylation treatment in three different assays used for the measurement of oxytocin in saliva of pigs

Oxytocin is a hormone that is increasingly being used for welfare evaluation in animals. Although several types of samples have been used for oxytocin measurement, saliva can be a suitable option for pigs producing less stress than blood sampling. In this study, 3 different methods for oxytocin measurements, 2 based on alphaLISA technology (one with a monoclonal and other with a polyclonal antibody) and one commercially available kit, were compared in saliva of pigs. These methods were used in saliva samples obtained from female pigs at 3 different days during gestation and lactation, with and without a reduction/alkylation (R/A), which is a procedure for breaking the links between oxytocin and proteins of the sample. The assays showed a different behavior after the R/A procedure, with no significant changes in the oxytocin results in case of the alphaLISA monoclonal method, a significant decrease with the alphaLISA polyclonal method, and a significant increase with the commercial kit. Although all assays showed a similar tendency in detecting the changes in oxytocin during gestation and lactation, they showed changes of different magnitude and statistical signification. This report indicates that different assays can measure different forms of oxytocin present in saliva and can have a different behavior after R/A of the sample and when are used to measure oxytocin in gestation and lactation.

Measurement of cortisol, cortisone and 11β-hydroxysteroid dehydrogenase type 2 activity in hair of sows during different phases of the reproductive cycle

Two sensitive assays based on AlphaLISA technology were developed and validated for the measurement of cortisol and cortisone in hair of pigs, that also enabled estimation of 11β-hydroxysteroid dehydrogenase type 2 activity. These assays were applied to hair samples from sows (n = 32) collected at 5 days before, and at 23 and 59 after farrowing, in reproductive cycles in two different periods: spring-summer (n = 16) and winter-spring (n = 16). The assays were precise (imprecision <12%) and accurate (recovery range, 80-115%) for cortisol and cortisone determination. Hair cortisone concentrations and the cortisone/cortisol ratio (an estimate of 11β-hydroxysteroid dehydrogenase isoenzyme type 2 activity) increased after farrowing more than cortisol, being these changes of higher magnitude during periods of higher atmospheric temperature. The measurement of hair cortisone concentrations and estimations of the activity of the 11β-hydroxysteroid dehydrogenase isoenzyme type 2, measured by the assays developed in this study, are complementary biomarkers to hair cortisol, and can increase at periods associated with stress, such as farrowing and lactation, especially at high atmospheric temperatures. .

Salivary D-dimer in pigs: Validation of an automated assay and changes after acute stress

D-dimer is a peptide found in serum and is derived from the degradation of blood clots. Even though it has been analysed in human saliva, D-dimer has not been previously evaluated in the saliva of any veterinary species, and its source and role remain unknown. The objectives of this research were firstly, to validate the use of an automated method for the measurement of D-dimer in porcine saliva, and secondly, to evaluate whether D-dimer concentration changes in pig saliva after an acute stress stimulus. For this purpose, a complete analytical validation of a commercially-available immunoturbidimetric assay was carried out. In addition, an experimental acute stress model was induced in 11 pigs based on a technique involving restraint by nose-snare immobilisation for 1 min. Saliva samples were subsequently collected at different times and D-dimer, salivary alpha-amylase (sAA) and cortisol were assessed in order to evaluate changes in its concentrations after the stress induction. The D-dimer automated assay showed adequate reproducibility and sensitivity, with coefficients of variation below 10% and a limit of quantification of 0.167 μg/mL fibrinogen equivalent units (FEU). It also showed a high accuracy, determined by linearity under dilution and recovery tests. In the stress model, a significant increase (P < 0.05) in salivary D-dimer 15 min after the stress stimulus and a positive correlation between D-dimer and sAA (r = 0.51; P < 0.001) were observed. These results indicate that D-dimer can be measured in porcine saliva with an automated method and suggest that its concentration can be influenced by stressful conditions.

Use of proteases for the evaluation of the different adiponectin isoforms in the dog

Adiponectin (ADP) is an adipokine secreted by adipose tissue with anti-inflammatory, antiatherogenic, and antidiabetic properties. In human serum, it is presented as three different forms: low molecular weight (LMW), medium molecular weight (MMW), and high molecular weight (HMW). High molecular weight isomer is the most active form of ADP and is more closely related with obesity-induced insulin resistance and metabolic syndrome than total ADP. Selective protease treatment can be used in humans to isolate the different ADP isoforms but this has not been applied in any veterinary species. Therefore, the objective of this study was to evaluate if the selective protease digestion is able to differentiate serum ADP isomers in dog samples, and if these isomers could change in obese dogs after a weight loss program. A Western blotting analysis confirmed that digestion with protease K showed only the HMW forms of ADP, whereas the use of protease A showed the HMW and MMW forms. This specific protease digestion was applied to serum obtained from 14 obese beagle dogs before and after a weight loss program and total ADP, HMW, and LMW forms increased significantly after the weight reduction. In conclusion, the use of selective protease digestion can be applied in canine serum as a procedure for detecting the different ADP isomers. In addition, by this procedure, it was showed that the HMW and LMW forms were increased after a weight loss program in our experimental conditions.

Oxytocin in saliva of pigs: an assay for its measurement and changes after farrowing

Oxytocin is a hormone of interest in reproduction, but also in the field of psychology and behavior, being considered as a biomarker of positive emotions. Saliva can be a noninvasive way to measure oxytocin, which is very useful in species such as the pig where blood collection can produce a high degree of stress. In this study, a new assay for oxytocin measurement was developed, analytically validated, and used to measure possible changes in oxytocin in saliva of female pigs at different days after farrowing. The assay showed an adequate accuracy and precision and does not need a previous extraction step. In addition, oxytocin concentrations were significantly higher at day 1 of lactation than at day 9 after farrowing, but levels increased at day 20 again. This assay can contribute to a wider use of oxytocin measurements in pigs as it is a noninvasive sampling procedure that minimizes stress.

Changes in saliva proteins in two conditions of compromised welfare in pigs: An experimental induced stress by nose snaring and lameness

The aim of this study was to identify biological pathways and proteins differentially expressed in saliva of pigs in two conditions of compromised welfare: an acute stress consisting of restraint with a nose snare and in pigs with lameness which is a highly frequent problem in the swine industry. For this purpose, high-resolution quantitative proteomics based on Tandem Mass Tags labelling was used. Four proteins showed significant differences in the conditions of compromised welfare, namely cornulin, the heat shock protein 27 and lactate dehydrogenase (LDH), that showed significant increases, whereas immunoglobulin J chain showed a significant decrease. LDH, which was the protein that showed the highest differences, was selected for validation and clinical evaluation as a diagnostic biomarker. Significant changes in this protein were observed between pigs restrained with a nose snare and pigs with lameness compared with healthy pigs when measured with available commercial assays in a larger population of pigs. In conclusion, this study reports that in situations of compromised welfare on farm, such as acute stress and lameness in pigs, there are changes in proteins and metabolic pathways in saliva, and describes a series of proteins that could potentially be used as biomarkers for both short term acute stress and longer term chronic stress of lameness. These biomarkers would have the advantage of being measured in saliva by a noninvasive and not stressful collection sampling procedure.

Changes in saliva analytes in equine acute abdominal disease: a sialochemistry approach

BACKGROUND

The biochemical components of saliva can change in certain pathologies in horses, for example in acute abdominal disease. The aim of this study was (1) to evaluate if a panel of biochemical analytes usually used in serum can be measured in saliva of horses and (2) to study the possible changes of these biochemical analytes in saliva of horses affected by acute abdominal disease. A panel of 23 analytes was analytically validated in saliva of horses and possible changes in these analytes in a pilot study with six healthy horses and six horses with acute abdominal disease were evaluated. The analytes with significant changes were then evaluated in a larger population of 20 healthy and 37 diseased horses.

RESULTS

Seven analytes showed significant increases in the pilot study which were confirmed in the larger population. The analytes which showed significant changes, and their median fold increase and significance shown in the larger population were salivary γ-glutamyl transferase (gGT, 2.3 fold, P = 0.001), creatine kinase (CK, 6.2 fold, P < 0.001), urea (2.3 fold, P = 0.001), total bilirubin (2.6 fold, P < 0.001), total proteins (3.2 fold, P < 0.001), phosphorus (P, 4.5 fold, P < 0.001) and alpha-amylase (sAA, 8.5 fold, P < 0.001). Total proteins, P and sAA showed sensitivities higher than 70% at their optimal cut-off points and a specificity of 100% in differentiating between healthy horses and those with acute abdominal disease.

CONCLUSIONS

A panel of 23 biochemical analytes can be measured in saliva of horses, where gGT, CK, urea, total bilirubin, total protein, P and sAA levels are raised in horses with acute abdominal disease.

Salivary alpha-amylase activity and concentration in horses with acute abdominal disease: Association with outcome

BACKGROUND

Salivary biomarkers could be useful to objectively evaluate critical illness and prognosis for survival in horses with acute abdominal disease.

OBJECTIVES

To compare salivary alpha-amylase (sAA) activity and concentration in healthy horses and horses with acute abdominal disease, and evaluate the association between sAA activity and concentration with disease severity and outcome.

STUDY DESIGN

A prospective cohort.

METHODS

sAA activity, measured using a colorimetric commercial kit, and concentration, measured using a Time-resolved immunofluorometric assay, in 25 healthy horses and in 33 horses with acute abdominal disease was compared using an ANOVA. Associations between survival to discharge and sAA activity and concentration and other clinical parameters were examined using univariable logistic regression and Spearman correlation.

RESULTS

sAA activity and concentration were different between healthy (median = 4.3 [2.6-11.2] IU/L and 58.4 [53.4-80.6] ng/mL, respectively) and diseased (median = 29.8 [14.2-168.9] IU/L and 388.3 [189.1-675.8] ng/mL, respectively) (P<0.001). The sAA activity was higher in non-survivors (median = 479.0 [78.7-2064.0] IU/L, n = 8) compared to survivors (median = 19.3 [12.1-103.7] IU/L, n = 25, P<0.001) and sAA activity and concentration correlated (P<0.001) moderately with HR (r = 0.66 and r = 0.61, respectively). sAA activity correlated weakly with salivary cortisol (r = 0.45, P<0.001) and systemic inflammatory response syndrome score (r = 0.43, P<0.05), while activity and concentration correlated (P<0.001) moderately with plasma lactate concentration (r = 0.57 and r = 0.60, respectively). The sAA activity was significantly (P = 0.01) associated with increased risk of nonsurvival.

MAIN LIMITATIONS

Pain scores were not recorded. The sample population was small.

CONCLUSIONS

The sAA activity, but not concentration, shows potential as a biomarker of prognosis for survival in horses with acute abdominal disease. The summary is available in Spanish - see Supporting Information.

Glucose, fructosamine, and insulin measurements in saliva of dogs: variations after an experimental glucose administration

The aim of this study was to evaluate if glucose, fructosamine, and insulin levels can be measured in saliva of dogs and assess the changes in these compounds after an experimental glucose administration. Automated spectrophotometric assays for glucose and fructosamine and an ELISA assay for insulin measurements were validated in saliva of dogs, by evaluating precision, accuracy, and limits of detection. In addition, an intravenous glucose bolus was administrated to 10 beagles and fasting serum and saliva samples were obtained immediately before and 5, 10, 20, 30, and 45 min after glucose infusion. The results of the between-run imprecision gave mean CVs of 6.16, 9.40, and 3.10% for glucose, fructosamine, and insulin, respectively. Linearity under dilution showed coefficient of correlation of 0.999, 0.994, and 0.990 for glucose, fructosamine, and insulin, respectively. The LDs were 0.04 mg/dL, 4.08 μmol/L, and 0.02 μg/mL for glucose, fructosamine, and insulin, respectively. The glucose administration caused an increase in serum and salivary levels of glucose with a peak in salivary levels at 30 min and of insulin with a peak in salivary levels at 45 min, while fructosamine did not change. No correlations between serum and salivary concentrations were found for any compound. It is concluded that glucose, fructosamine, and insulin can be measured in saliva of dogs, and an experimental administration of glucose in this species can lead to increases in glucose and insulin in saliva.

Changes in alpha-amylase activity, concentration and isoforms in pigs after an experimental acute stress model: an exploratory study

BACKGROUND

Salivary alpha-amylase (sAA) is considered a non-invasive biomarker of acute stress that can be evaluated by changes in activity and concentration, and also by changes in its isoforms, although this last way of evaluation has never been used in veterinary medicine. This research evaluated the changes of sAA by three different ways in which sAA can be evaluated in an experimental acute stress model in six pigs based in a technique of temporarily restraining. These ways of evaluation were 1) activity by a spectrophotometric assay, 2) concentration by a fluorometric assay, and 3) isoforms of the enzyme by a Western blot.

RESULTS

Although salivary cortisol significantly increased due to the stimulus of stress and all the pigs manifested signs of stress by high-pitched vocalization, sAA activity showed an increase of different degree in the six pigs after the stress stimulus, while sAA concentration showed decreases in four of the six pigs. sAA activity did not correlate with sAA concentration or salivary cortisol, and a low correlation was observed between sAA concentration and salivary cortisol (r = 0.48, p = 0.003). The inter-individual variability was higher in sAA activity than in sAA concentration and salivary cortisol. Finally, three possible isoforms of sAA at 154-160 kDa, 65-66 kDa and 59-60 kDa were observed that showed different dynamics after the stress induction.

CONCLUSIONS

Although this pilot study's results should be taken with caution due to the low sample size, it reveals a different behavior between sAA activity and concentration in pig after an acute stressful stimulus leading to evident external signs of stress by high-pitched vocalization, and opens a new field for the evaluation of possible selected isoforms of sAA as potential biomarkers of stress.

Salivary alpha-amylase activity and cortisol in horses with acute abdominal disease: a pilot study

BACKGROUND

The aim of this study was to evaluate salivary alpha-amylase (sAA), considered a non-invasive biomarker for sympathetic nervous system (SNS) activity, and salivary cortisol as possible pain-induced stress biomarker, in horses with acute abdominal disease. Therefore, a prospective observational study was performed in which both biomarkers were analyzed in a group of horses with acute abdomen syndrome, and compared with a group of healthy control horses by an unpaired Student's t-test. In addition, the possible relationship between both biomarkers, the score in Equine Acute Abdominal Pain scales version 1 (EAAPS-1 scale), Heart Rate (HR) and Respiratory Rate (RR), plasma lactate, the systemic inflammatory response syndrome (SIRS) score and serum amyloid A (SAA) concentration was assessed by a Spearman correlation test.

RESULTS

A total of 30 horses were included in the study, 19 with acute abdominal disease diagnosed as large colon displacements, simple impactions of the pelvic flexure, spasmodic colics and enteritis and 11 healthy ones. sAA activity (24.5 median-fold, P <  0.0001) and salivary cortisol (1.7 median-fold, P <  0.01) were significantly higher in horses with acute abdomen than in healthy horses. sAA activity was significantly correlated with EAAPS-1 scale (r = 0.78, 95% confidence interval [CI] 0.38-0.89, P < 0.001) and SIRS score (r = 0.49, 95% CI 0.03-0.78, P < 0.05). Neither sAA nor salivary cortisol correlated with HR, RR, plasma lactate and SAA.

CONCLUSIONS

Although this study should be considered as preliminary one, alpha-amylase measurements in saliva could be a biomarker of pain-induced stress in horses with acute abdominal disease.

Evaluation of adenosine deaminase in saliva and serum, and salivary α-amylase, in canine pyometra at diagnosis and after ovariohysterectomy

An assay for adenosine deaminase (ADA) was validated in serum and saliva in dogs. Changes in ADA and salivary α-amylase activities were analysed in 26 bitches diagnosed with pyometra and compared with activities in 19 healthy bitches. All animals were classified according to the American Society of Anaesthesiologists (ASA) scoring for physical status. In the validation study, the ADA assay had an imprecision<12% and determination coefficients>0.90 in linearity under dilution experiments, with recoveries of 99.2-114.4%. On the day of presentation, salivary ADA activity was significantly higher in dogs with pyometra than in healthy dogs (median values 7.1IU/L vs. 0.8IU/L, respectively; P<0.01). ADA had a moderate positive correlation with leucocyte and band neutrophil counts, haptoglobin, salivary α-amylase and ASA score, and a low positive correlation with C-reactive protein. There were no significant differences in salivary α-amylase activity between dogs with pyometra and healthy dogs (57.3IU/L vs. 27.4IU/L, respectively). Salivary α-amylase had a low correlation with ASA grade, and leucocyte and band neutrophil counts. In 7/26 bitches with pyometra that were sampled 3 and 10days after ovariohysterectomy, there were no significant changes in α-amylase or ADA activities. These results indicate that ADA activity is increased in the saliva of bitches with pyometra, probably related to systemic inflammation.

Diagnostic accuracy of porcine acute phase proteins in meat juice for detecting disease at abattoir

The aim of this work was to evaluate whether acute phase protein (APP) determinations could assist Official Veterinarians carrying out work in slaughterhouses. To test this hypothesis, the diagnostic accuracy of APP determinations in meat juice of pigs was analysed to differentiate between healthy and diseased pigs. One hundred and one pigs of two different origins were classified into two groups according to their health status (healthy and diseased pigs), which was determined by a veterinary clinical examination on the farm. To assess the pigs' immune status, against the main porcine diseases, serological analyses were monitored. A general idea of the degree of disease coverage was analysed by examining organ lesions postmortem. Haptoglobin (Hp) and C reactive protein (CRP) were measured in meat juice samples. 72.13 per cent of pigs appeared to be seropositive for the porcine respiratory and reproductive syndrome virus, and almost 86.2 per cent of them had concomitant infections with other pathogens, such as Porcine circovirus type 2 or Swine influenza virus. Median Hp and CRP concentrations were significantly higher in diseased animals at different stages of the production chain, when compared with levels found in healthy finishing pigs (P<0.0001). Receiver operating characteristic analysis showed the highest sensitivity-specificity pairs, nearly 80-90 per cent, at cut-off levels of 83 and 10 µg/ml for Hp and CRP determinations, respectively, with high AUCs 0.9. This cut-off could be useful for veterinary inspections at the time of slaughter, to differentiate between the carcase of a healthy animal and the carcase of an animal suffering from a systemic disease, which should be completely condemned.

Acute phase protein response in heartworm-infected dogs after adulticide treatment

During the adulticide treatment of Dirofilaria immitis the worms die releasing fragments of parasites and causing pulmonary thromboembolisms which could exacerbate the clinical condition. To determine the utility of acute phase proteins (APPs) to monitor the progression of the treatment, different positive [C-reactive protein (CRP), haptoglobin (hp)] and negative [albumin, paraoxonase-1(PON-1)] APPs were measured in 15 heartworm-infected dogs (5 with high and 10 with low parasite burden) following adulticide treatment. The results showed increased concentrations of CRP, decreased concentrations of haptoglobin and PON-1 in infected dogs before starting the treatment. Progressive but not significant increases were observed in PON-1 activity and albumin concentration along the treatment. After the treatment with doxycycline and ivermectine a decrease in CRP and Hp levels was experienced, which could reflect a reduction of the vascular inflammation caused by the elimination of Wolbachia and reduction of microfilariae. Fifteen days after the first melarsomine injection, marked increases in CRP and Hp were observed, which could be due to pulmonary inflammation and thromboembolism caused by the post-adulticide death of the worms. This increase was greater in dogs with high parasite burden. As the pathology disappeared, there was an improvement in the concentrations of CRP and Hp, returning into reference values in dogs with low parasite burden at the end of the treatment. The measurement of CRP and Hp could be a resource of support to evaluate the magnitude of the post-adulticide complications during the adulticide treatment of D. immitis.

Serum biomarkers of oxidative stress in cats with feline infectious peritonitis

The purpose of this study was to elucidate the possible presence of oxidative stress in cats naturally affected by feline infectious peritonitis (FIP) by investigating two antioxidant biomarkers in serum: paraoxonase-1 (PON1) and total antioxidant capacity (TAC). PON1 was measured by spectrophotometric assays using three different substrates: p-nitrophenyl acetate (pNA), phenyl acetate (PA) and 5-thiobutil butyrolactone (TBBL), in order to evaluate possible differences between them. The PA and TBBL assays for PON1 and the assay for TAC were validated, providing acceptable precision and linearity although PA and TAC assays showed limit of detection higher than the values found in some cats with FIP. Cats with FIP and other inflammatory conditions showed lower PON1 values compared with a group of healthy cats with the three assays used, and cats with FIP showed significant decreased TAC concentrations. This study demonstrated the existence of oxidative stress in cats with FIP.

Different stressors elicit different responses in the salivary biomarkers cortisol, haptoglobin, and chromogranin A in pigs

Most commonly, salivary cortisol is used in pig stress assessment, alternative salivary biomarkers are scarcely studied. Here, salivary cortisol and two alternative salivary biomarkers, haptoglobin and chromogranin A were measured in a pig stress study. Treatment pigs (n = 24) were exposed to mixing and feed deprivation, in two trials, and compared to untreated controls (n = 24). Haptoglobin differed for feed deprivation vs control. Other differences were only found within treatment. Treatment pigs had higher salivary cortisol concentrations on the mixing day (P < 0.05). Chromogranin A concentrations were increased on the day of refeeding (P < 0.05). Haptoglobin showed a similar pattern to chromogranin A. Overall correlations between the salivary biomarkers were positive. Cortisol and chromogranin A were moderately correlated (r = 0.49, P < 0.0001), correlations between other markers were weaker. The present results indicate that different types of stressors elicited different physiological stress responses in the pigs, and therefore including various salivary biomarkers in stress evaluation seems useful.

An automated turbidimetric method for fibrinogen determination in dogs

BACKGROUND

Several methods have been used for fibrinogen determination in dogs, but to the authors' knowledge, methods based on ammonium sulfate precipitation have not yet been reported in this species.

OBJECTIVES

The aim of this study was to develop and validate an automated method based on ammonium sulfate precipitation for canine fibrinogen determination.

METHODS

A reagent containing ammonium sulfate, sodium chloride, and K2 EDTA was used to precipitate fibrinogen at a final ammonium sulfate concentration of 0.57 M and final turbidity was measured on a Cobas Mira Plus autoanalyzer. Analytic validation included imprecision, accuracy, comparison with reference method (Clauss), limits of detection and quantification, and the evaluation of the influence of different anticoagulants. For diagnostic validation, fibrinogen was determined in a group of Beagle dogs before and after neutering, and in dogs affected by diseases known to produce low fibrinogen plasma concentration, such as liver insufficiency, disseminated intravascular coagulation, and protein-losing enteropathy.

RESULTS

Low imprecison (<4%), excellent recovery (>90%), and low bias (0.092 g/L) with respect to Clauss method indicated a high reproducibility and accuracy. Limits of detection and quantification were 0.01 and 0.22 g/L, respectively. The method was applicable in plasma samples anticoagulated with EDTA, heparin, or sodium citrate. The fibrinogen concentration in Beagle dogs after neutering was increased, and decreased in animals with disseminated intravascular coagulation, liver insufficiency, or gastrointestinal protein loss.

CONCLUSIONS

The automated method validated in this study represents a rapid, cheap, and easy protocol to quantify canine fibrinogen in routine practice.

Detection of potential markers for systemic disease in saliva of pigs by proteomics: a pilot study

Animals with different health status have been studied in order to extend the knowledge about protein composition of porcine saliva samples and to discover potential salivary markers for systemic disease in porcine production. Clinical examination of animals was performed at farm level where 10 healthy pigs and 10 animals with evident clinical signs of disease were randomly selected. Saliva and blood samples were obtained and afterwards animals were humanely sacrificed to perform a complete necropsy. Levels of two acute phase proteins, haptoglobin and C-reactive protein, were used to identify possible active infections of the animals. Moreover, serological analysis, to the main porcine infectious diseases in the area, was performed. Salivary proteins were separated by two-dimensional gel electrophoresis followed by mass spectrometry for the identification of specific proteins. A total of 58 spots out of 75 were successfully identified by MS, which correspond to 20 unique proteins. Two different approaches were used to perform a statistical comparison of saliva protein patterns from healthy and diseased animals using the relative spot volume (% spot volume/total volume of all spot in the gel, approach "A") or taking also into account the total protein content of each saliva sample (μg of spot/mL of saliva, approach "B"). Both analyses showed three proteins in common that are differentially regulated between states. However, approach B was selected for biomarker searching since it gave an estimation of protein concentration and showed differential expression of proteins between both health states in a total of 10 proteins, which were up-regulated in disease. Mass spectrometric analysis identified those proteins as salivary lipocalin, lipocalin 1, double headed protease inhibitor protein, adenosine deaminase, haptoglobin, albumin fragments, S100-A8, S100-A9, S100-A12 and pancreatic alpha amylase. These proteins could be considered as potential salivary markers of disease.

Why working with porcine circulating serum amyloid A is a pig of a job

Serum amyloid A (SAA) is a major acute phase protein in most species, and is widely employed as a health marker. Systemic SAA isoforms (SAA1, and SAA2) are apolipoproteins synthesized by the liver which associate with high density lipoproteins (HDL). Local SAA (SAA3) isoforms are synthesized in other tissues and are present in colostrums, mastitic milk and mammary dry secretions. Of systemic SAA the bulk is monomeric and bound to HDL, and a small proportion is found in serum in a multimeric form with a buried HDL binding site. In most species, systemic SAA could easily be studied by purifying it from serum of diseased individuals by hydrophobic interaction chromatography methods. For years, we were not able to isolate systemic pig SAA using the latter methods, and found that the bulk of pig SAA did not reside in the HDL-rich serum fractions but in the soluble protein fraction mainly as a multimeric protein. Based on these surprising results, we analysed in silico the theoretical properties and predicted the secondary structure of pig SAA by using the published pig primary SAA amino acid sequence. Results of the analysis confirmed that systemic pig SAA had the highest homology with local SAA3 which in other species is the isoform associated with non-hepatic production in tissues such as mammary gland and intestinal epithelium. Furthermore, the primary sequence of the pig SAA N-terminal HDL binding site did differ considerably from SAA1/2. Secondary structure analysis of the predicted alpha-helical structure of this HDL binding site showed a considerable reduction in hydrophobicity compared to SAA1/2. Based on these results, it is argued that systemic acute phase SAA in the pig has the structural properties of locally produced SAA (SAA3). It is proposed that in pig SAA multimers the charged N-terminal sequence is buried, which would explain their different properties. It is concluded that pig systemic SAA is unique compared to other species, which raises questions about the proposed importance of acute phase SAA in HDL metabolism during inflammation in this species.

Effects of thyroxin therapy on different analytes related to obesity and inflammation in dogs with hypothyroidism

Hypothyroidism in dogs is accompanied by changes in intermediary metabolism including alterations in bodyweight (BW), insulin resistance, and lipid profile. In this study, changes in selected adipokines (adiponectin, leptin), butyrylcholinesterase (BChE), and acute phase proteins, including C-reactive protein, haptoglobin (Hp) and serum amyloid A (SAA), were studied in dogs with hypothyroidism under thyroxin therapy. Blood samples were collected when hypothyroidism was diagnosed (before treatment) and after treatment with thyroxin. Twenty-eight of 39 dogs exhibited a good therapeutic response (group A), whereas the remainder were considered to have been insufficiently treated (group B). Following treatment, group A dogs demonstrated a statistically significant decrease in canine thyroid stimulating hormone (c-TSH) (P<0.001) and an increase in free thyroxine (fT4) (P<0.001) concentrations, associated with a significant decrease in BW (P<0.05), leptin (P<0.01), and adiponectin, (P<0.001) and an increase in BChE (P<0.01) and Hp (P<0.05). Group B dogs showed no statistically significant changes in c-TSH, but had a significant increase in fT4 (P<0.001) accompanied by a significant decrease in adiponectin (P<0.05) of lower magnitude than group A. No significant changes in the mean circulating levels of APPs were observed in both groups, with the exception of an increase in Hp (P<0.05) in group A. In summary, the successful treatment of hypothyroidism reduces circulating levels of adiponectin and leptin, while increasing BChE activity in dogs. The mean increase in Hp values and decrease in SAA for some of the dogs after treatment warrants further investigation.

Acute phase response to Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' infection in FIV-infected and non-FIV-infected cats

The pathogenicity of Haemoplasma spp. in cats varies with 'Candidatus Mycoplasma haemominutum' (CMhm) causing subclinical infection while Mycoplasma haemofelis (Mhf) often induces haemolytic anaemia. The aims of this study were to characterise the acute phase response (APR) of the cat to experimental infection with Mhf or CMhm, and to determine whether chronic feline immunodeficiency virus (FIV) infection influences this response. The acute phase proteins serum amyloid A (SAA), haptoglobin (Hp) and α-1-acid glycoprotein (AGP) concentrations were measured pre-infection and every 7-14 days up to day 100 post-infection (pi) in cats infected with either Mhf or CMhm. Half of each group of cats (6/12) were chronically and subclinically infected with FIV. Marbofloxacin treatment was given on days 16-44 pi to half of the Mhf-infected cats, and on days 49-77 pi to half of the CMhm-infected cats. FIV-infected animals had significantly lower AGP concentrations, and significantly greater Hp concentrations than non-FIV-infected cats when infected with CMhm and Mhf, respectively. Both CMhm and Mhf infection were associated with significant increases in SAA concentrations, while AGP concentrations were only significantly increased by Mhf infection. Mhf-infected cats had significantly greater SAA concentrations than CMhm-infected animals. Both Mhf and CMhm infections were associated with an APR, with Mhf infection inducing a greater response. Chronic FIV infection appeared to modify the APR, which varied with the infecting Haemoplasma species.

Local identification of porcine haptoglobin in salivary gland and diaphragmatic muscle tissues

In order to clarify the origin of the haptoglobin (Hp) quantified in saliva and meat juice samples, the extrahepatic localization of Hp in salivary gland and in diaphragmatic muscle, as part of the systemic acute phase response in pigs, was studied by immunohistochemistry. For this purpose a specific monoclonal antibody (mAb) produced by immunising mice with purified porcine Hp was used. Reactivity of the mAb was assessed by direct ELISA and by western blot, which showed the ability and specificity of the mAb to identify porcine haptoglobin as a purified antigen or in porcine serum in a native or denatured but non-reduced state. Five healthy and five diseased pigs were sampled at slaughter for serum and tissue procurement. Hepatic immunohistochemical analysis was used as control of the acute phase reaction status. In the liver, cell immunostaining revealed a perinuclear, cytoplasmic localization of Hp within hepatocytes, following mainly a periacinar pattern. Extrahepatic immunohistochemical analysis revealed positive cells in the glandular acini and duct epithelial cells of the salivary gland and intrasarcoplasmic immunolabelling of random diaphragmatic myofibers. A possible role of both salivary gland and diaphragmatic muscle on local Hp production could be postulated based on the present immunohistochemical study, which supports the concept that other cells besides hepatocytes may have the potential to produce Hp in the pig.

Acute phase proteins as a tool for differential diagnosis of wasting diseases in growing pigs

The concentrations of haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA) were measured in wasted pigs, first to evaluate their usefulness in the diagnosis of infectious, wasting diseases in pigs, and second, to evaluate whether their concentrations can distinguish the lymphoid depletion score in the lymph tissues of wasted affected pigs. Fifty-three wasted pigs and seven specific pathogen free (SPF) pigs were postmortem examined. Gross lesions were evaluated and samples for histopathological, immunohistochemical, molecular biology and microbiological analysis were taken. Thirty-one pigs were diagnosed as postweaning multisystemic wasting syndrome (PMWS) and 22 as porcine respiratory disease complex (PRDC). Lymphoid depletion degree in lymph tissues of PMWS and PRDC affected pigs was determined. Serum Hp was significantly higher in pigs with PRDC in comparison with the PMWS affected pigs. Serum CRP concentration was significantly lower in pigs with PRDC than in PMWS affected pigs (P<0.001). CRP and SAA levels increased with the lymphoid depletion score, presenting statistical differences between pigs with no depletion and pigs with low, moderate or severe lymphoid depletion (P<0.05, P<0.05 and P<0.001 for CRP and P<0.01, P<0.01 and P<0.01 for SAA, respectively). Hp was higher in pigs with no or low depletion compared with the pigs suffering severe lymphoid depletion (P<0.001 and P<0.05, respectively).

Validation of three commercially available immunoassays for quantification of IgA, IgG, and IgM in porcine saliva samples

The objectives of this study were to perform the optimization and validation of three commercially available immunoassays for the measurement of IgA, IgG, and IgM (Igs) in porcine saliva samples and to determinate if their concentrations may be used to distinguish healthy from diseased animals. Intra and inter assay coefficients of variation were lower than 15% in all cases. All methods showed good linearity and recovery; and detection limits were low enough to detect Igs levels in healthy and diseased animals. The clinical validation showed an increase statistically significant (P<0.05) in the group of diseased animals versus healthy pigs. Therefore, these assays may be used in porcine saliva samples, in addition, the measurement of Igs in saliva could be a practical tool, simple and minimally invasive, to evaluate the humoral immune status of pigs.

Development and validation of a novel competitive ELISA for the detection of serum amyloid A in pigs

The objective of this study was to develop a novel competitive ELISA to measure the acute phase protein serum amyloid A (SAA) in pigs using species-specific reagents. Polyclonal antibodies were produced in rabbits immunised with recombinant porcine SAA (rSAA) expressed in Escherichia coli. Both the rSAA and polyclonal antibodies were used to develop a novel competitive assay that was analytically and clinically validated. This assay had within- and between-run coefficients of variation of 8.6% and 25%, respectively, and demonstrated a high level of accuracy as determined by linearity-under-dilution (correlation coefficient, r=0.965). The analytical and functional limits of detection were 3.3 and 105.02mg/L, and the upper and lower quantification limits were 66.9 and 2.8mg/L, respectively. Statistically significant differences (P<0.0001) were found between the concentrations of SAA in healthy and diseased pigs. This novel assay precisely and sensitively measures SAA levels in pigs and will facilitate the more accurate assessment and study of the acute phase response in this species.

Acute phase response in porcine reproductive and respiratory syndrome virus infection

This study was focused on the changes observed in the serum concentration of haptoglobin (Hp), C-reactive protein (CRP), serum amyloid A (SAA) and Pig-major acute protein (Pig-MAP), during experimental porcine reproductive and respiratory syndrome virus (PRRSV) infection and in their relationship with the expression of interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α). Hp and Pig-MAP serum levels were increased at 10 dpi, but CRP and SAA showed a delayed and highly variable increase. All three proinflammatory cytokines were poorly expressed, and only a mild increase in IL-1β was observed at 7 dpi. The increased expression of Hp coincided with the light enhancement observed in both IL-6 and TNF-α, and might be related with an increased expression of IL-10. The low expression of TNF-α might point to a possible mechanism of viral evasion of host-immune response. This issue and the delayed expression of CRP and SAA should be taken into account in future studies about modulation of the immune response by PRRSV infection.

Use of saliva for haptoglobin and C-reactive protein quantifications in porcine respiratory and reproductive syndrome affected pigs in field conditions

The purpose of this study was to study the use of saliva samples as alternative to serum for acute phase protein (APP) quantifications in pigs at field conditions. To this end, haptoglobin (Hp) and C-reactive protein (CRP) concentrations were examined in 100 animals at different ages. Sixty pigs were from a farm with chronic PRRS virus infection and 40 from a specific pathogen free (SPF) farm. A serological study was performed to obtain an overview of the immune status of animals and to evaluate possible concomitant infections in animals with PRRS infection. The results reported in this study showed that both saliva and serum samples had higher APP concentrations in PRRS pigs aged 8-9, 17-18 and 24-25 weeks in conventional herds than SPF pigs of the same age (p<0.05). In addition, increases in APP were obtained with age independently of the health status of the animals. According to the ROC analyses performed, saliva could be a better specimen than serum to quantify Hp and CRP levels in field conditions and may contribute to a more efficient detection of diseased animals at farm level.

C-reactive protein quantification in porcine saliva: a minimally invasive test for pig health monitoring

Study objectives were to investigate whether C-reactive protein (CRP) in pig saliva could be quantified using an adapted, time-resolved immunofluorometry assay (TR-IFMA), and to determine whether the assay could distinguish healthy from diseased animals. The test method had intra- and inter-assay coefficients of variation of 5.75% and 9.73%, respectively, the limit of detection was 0.47ng/mL and the coefficient of determination was 0.98. Analysis of CRP concentrations in paired serum and saliva samples from 50 pigs gave a positive correlation (r=0.702, P<0.01) and the salivary CRP concentration was able to distinguish healthy from diseased animals in 62 samples from pigs with naturally occurring or experimentally-induced inflammation. The results suggest that this minimally invasive, straightforward and sensitive assay may be useful in pig health and welfare monitoring.

Establishment of the European College of Veterinary Clinical Pathology (ECVCP) and the current status of veterinary clinical pathology in Europe

After 5 years of development, the European College of Veterinary Clinical Pathology (ECVCP) was formally recognized and approved on July 4, 2007 by the European Board of Veterinary Specialisation (EBVS), the European regulatory body that oversees specialization in veterinary medicine and which has approved 23 colleges. The objectives, committees, basis for membership, constitution, bylaws, information brochure and certifying examination of the ECVCP have remained unchanged during this time except as directed by EBVS. The ECVCP declared full functionality based on the following criteria: 1) a critical mass of 65 members: 15 original diplomates approved by the EBVS to establish the ECVCP, 37 de facto diplomates, 7 diplomates certified by examination, and 5 elected honorary members; 2) the development and certification of training programs, laboratories, and qualified supervisors for residents; currently there are 18 resident training programs in Europe; 3) administration of 3 annual board-certifying examinations thus far, with an overall pass rate of 70%; 4) European consensus criteria for assessing the continuing education of specialists every 5 years; 5) organization of 8 annual scientific congresses and a joint journal (with the American Society for Veterinary Clinical Pathology) for communication of scientific research and information; the College also maintains a website, a joint listserv, and a newsletter; 6) collaboration in training and continuing education with relevant colleges in medicine and pathology; 7) development and strict adherence to a constitution and bylaws compliant with the EBVS; and 8) demonstration of compelling rationale, supporting data, and the support of members and other colleges for independence as a specialty college. Formal EBVS recognition of ECVCP as the regulatory body for the science and practice of veterinary clinical pathology in Europe will facilitate growth and development of the discipline and compliance of academic, commercial diagnostic, and industry laboratories in veterinary clinical pathology. Future needs are in developing sponsorship for resident positions, increasing employment opportunities, increasing compliance with laboratory, training, and continuing education standards, and advancing relevant science and technology.

Effects of haemolysis, lipaemia and bilirubinaemia in canine C-reactive protein and haptoglobin determination by time-resolved fluorometry: short communication

C-reactive protein (CRP) and haptoglobin (Hp) are well-known acute phase proteins in the dog. Currently, a commercial ELISA and a colorimetric assay are the methods of choice for measuring CRP and Hp, respectively; however, these assays showed interference when using haemolysed, lipaemic or hyperbilirubinaemic samples. Recently, time-resolved immunofluorometric assays (TR-IFMAs) have been developed for measuring canine CRP and Hp. The aim of the present study was to evaluate the effect of increasing concentrations of haemoglobin, lipids and bilirubin in CRP and Hp serum measurements using these new fluoroimmunoassays. Haemolysis was produced by freezing blood cells at -20 degrees C. The haemolysate was added to pooled sera at final concentrations of 0, 2.5, 5, 10, 20 and 40 g/L. A commercial emulsion of triglycerides was added to homologous pooled sera at 0, 0.35, 0.7, 1.4, 2.8, 5.6 and 11.2 mmol/L. Bilirubin, initially dissolved in dimethyl sulphoxide, was added to pooled sera at 0, 64.2, 128.4, 256.8, 513.7 and 1027.4 micromol/L. Addition of fresh haemolysate, triglycerides or bilirubin to serum samples did not affect either CRP or Hp concentrations (P > or = 0.18), so the TR-IFMAs could be an alternative to the traditional tests for measuring canine CRP and Hp in those laboratories where immunofluorometric assays are available.

Analytical validation of commercially available methods for acute phase proteins quantification in pigs

The aim of this study was to validate commercially available methods for porcine haptoglobin (Hp), C-reactive protein (CRP), serum amyloid A (SAA) and major acute phase protein (Pig-MAP) determinations. Intra and inter assay coefficients of variation (CVs) were lower than 20% in all cases with exception of inter assay CVs for CRP and Pig-MAP assays with samples of low acute phase proteins concentration, and for SAA assay at any acute phase proteins concentration. All methods showed good linearity and detection limits were low enough to detect APPs levels in healthy animals. Hp and SAA were very affected by haemolysis. Lipaemia influenced mainly on SAA determination. Over 15-fold increase was observed in CRP and SAA concentrations after artificially induced inflammation by a single subcutaneous dose of turpentine, whereas Hp and Pig-MAP increased less than 5-fold.

Validation of a commercially available human immunoturbidimetric assay for haptoglobin determination in canine serum samples

Haptoglobin is a positive acute-phase protein with a valuable role as a marker of inflammation in both human and veterinary medicine. The aim of this study was to validate a commercially available immunoturbidimetric method designed for human haptoglobin determination (Izasa SA, Barcelona, Spain) for its use in canine samples. Cross-reactivity between anti-human haptoglobin antiserum and canine haptoglobin was found when agarose gel immunodiffusion and ELISA tests were performed. The use of canine pooled serum with haptoglobin concentration of 6.3 g/L as standard provided higher analytical range than commercially available standards. Intra-assay and inter-assay coefficients of variation were 2.49% and 4.60%, respectively. A linear regression model between immunoturbidimetric results and a previously validated spectrophotometric method (Tridelta Development Limited, Ireland) yielded a slope at 95% confidence interval of 0.94 (0.86, 1.02) and y-intercept at 95% confidence interval of 0.11 (-0.59, 0.82). No significant differences were produced by anticoagulants, lipaemia and bilirubinaemia, although haemolysis significantly decreased haptoglobin. A significant increase of haptoglobin concentration was detected in inflammatory conditions such as pyometra and leishmaniasis, in neoplastic conditions, and after glucocorticoid administration. Canine serum haptoglobin concentration can be reliably measured using the commercially available Izasa immunoturbidimetric method developed for human haptoglobin determination. This method is precise and accurate, provides a wider analytical range than previous reported methods, and can be easily automated and used for routine haptoglobin determination in canine samples.

Porcine Acute Phase Protein Concentrations in Different Diseases in Field Conditions

Five acute phase proteins (APPs) [C-reactive protein (CRP), serum amyloid A (SAA), haptoglobin (Hp), pig-MAP and albumin] were measured in pigs with naturally occurring infections by porcine reproductive and respiratory syndrome virus (PRRSV), Aujeszky's disease virus (ADV), porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae, and in animals with tail and ear bites, arthritis and other acute inflammatory processes. Healthy specific pathogen-free (SPF) pigs were used as controls. In PRRSV-infected pigs, all APPs with the exception of pig-MAP exhibited significant changes compared with controls. In animals affected with ADV only Hp presented changes of statistical significance, whereas pigs with PCV2 showed marked modifications in all APPs tested. Animals affected with Mycoplasmosis showed concentrations of all positive APPs significantly above levels obtained in SPF pigs, though albumin concentrations did not differ from controls. Finally, all APPs studied showed substantial changes in pigs with acute inflammation. The results indicated that an acute phase response was developed in the different diseases studied, this response being higher in animals with clinical signs and concurrent bacterial processes. Haptoglobin would be the APP that better reflects pathological states; however, to get more complete and valuable information it might be advisable to perform APPs profiles including another APP, such as CRP or SAA.

Response of Broilers to Feeding Low-Calcium and Phosphorus Diets Plus Phytase Under Different Environmental Conditions: Body Weight and Tibiotarsus Mineralization

Three experiments on Ross broiler chickens were conducted in 3 locations: cages (Experiment 1), floor pens (Experiment 2), and commercial farms (Experiment 3). The effect of low-total P (TP) wheat-soybean based diets plus microbial phytase (Natuphos) was evaluated. Four experimental starter and finisher diets were used in a 2-phase feeding program, as follows: control diet (SC until 21 d, FC from 22 to 42 d); 2 diets (SL400 and SL600 until 21 d, FL400 and FL600 from 22 to 42 d) with low TP (0.61% for starter and 0.54% for finisher), including 400 and 600 U/kg of phytase, respectively; and a very low-TP (0.52% for starter and 0.44% for finisher) diet (SVL600 until 21 d, FVL600 from 22 to 42 d) with 600 U/kg of phytase. In Experiment 1 (broilers in cages had movement limitation and no access to litter), no differences in BW, tibiotarsus mineralization, or mineral metabolism were observed among diets. In Experiment 2 (broilers in floor pens had movement limitation and access to litter), at 21 d of age, the lowest tibiotarsus ash percentage and BW were shown by birds fed the SVL600 diet. At 42 d of age, broilers fed the FC diet were the lightest. For the rest of the parameters of tibiotarsus mineralization and mineral metabolism measured in Experiment 2, no differences were shown. In Experiment 3 (broilers in commercial farms had access to litter without movement limitation), the BW of broilers fed the SC diet was the highest at 21 d of age. At 42 d of age, the broilers fed FL400 and FL600 diets were the heaviest. At the end of Experiment 3, broilers fed the FC diet had the highest dry litter Ca and P, whereas broilers fed the FVL600 diet had the lowest values. In conclusion, the very low-TP wheat-soybean based diet supplemented with 600 U/kg of phytase was sufficient to optimize all the parameters measured in Experiment 1 but not in Experiments 2 and 3. Therefore, when evaluating Ca and P in phytase-supplemented diets for broilers, it is necessary to bear in mind the environmental conditions of experimentation.

Concentrations of C-reactive protein in effusions in dogs

The concentration of C-reactive protein (CRP) was measured in effusions from 50 dogs to assess the potential for measuring this protein to differentiate body cavity fluids. The effusions were classified as either transudates, modified transudates or exudates according to their total protein concentration, total nucleated cell count, cytological findings and aetiology, and the concentration of CRP was determined by a time-resolved immunofluorometric assay. There were significant differences between the concentrations of CRP in the three types of effusion; the highest concentrations were observed in the exudates (4.47 to 54.59 microg/ml), the lowest were in the transudates (0.0094 to 7.87 microg/ml), and the modified transudates contained intermediate concentrations of CRP (0.045 to 10.78 microg/ml). A cut-off value of 4 microg/ml had a sensitivity of 100 per cent and a specificity of 94.4 per cent for differentiating transudates from exudates, and a cut-off value of 11 microg/ml had a sensitivity of 88.2 per cent and a specificity of 100 per cent for distinguishing modified transudates from exudates. However, a cut-off value of 1 microg/ml had a lower sensitivity (80 per cent) and an unacceptably low specificity (66.7 per cent) for differentiating transudates from modified transudates.

Preliminary studies of serum acute-phase protein concentrations in hematologic and neoplastic diseases of the dog

Serum concentrations of acute-phase proteins (APPs): haptoglobin (Hp), ceruloplasmin (Cp), serum amyloid A (SAA), and C-reactive protein (CRP) were determined in healthy dogs (n = 15) and dogs with different diseases grouped as acute inflammation (I, n = 12), hematologic neoplasias (HT, including leukemia and lymphoma, n = 16), nonhematologic neoplasias (NHT, including epithelial, mesenchymal, and mixed, n = 20), and autoimmune hemolytic anemia (AIHA, n = 8). SAA and CRP were analyzed using commercially available enzyme-linked immunosorbent assay (ELISA) kits, and Hp and Cp were measured using colorimetric methods, all previously validated for use in dogs. Increased concentrations of all APPs were observed in all groups of diseased dogs, but statistical significance only was observed with Hp (I, P < .001; HT, P < .05), Cp (I, P < .05; AIHA, P < .01), and CRP (I, P < .001; HT, P < .001; AIHA, CRP P < .05). High variability in individual APPs within each group of diseases was found with no significant differences between leukemia and lymphoma as well as among different types of neoplasia. The AIHA group had smaller increases in Hp, SAA, and CRP but higher concentrations of Cp. When follow-up of individual cases was possible, a decrease in APPs generally was found in cases with favorable outcome. The results of this study suggest that neoplasia and hematologic diseases such as AIHA should be considered as possible causes of mild increases in APPs in dogs. Measurement of APPs may be helpful to assess clinical evolution and monitor treatment of these processes.

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).

Effects of different glucocorticoid treatments on serum acute phase proteins in dogs

The serum concentrations of haptoglobin, caeruloplasmin, C-reactive protein and serum amyloid A were measured in three groups of seven healthy dogs. Group 1 received a single dose of 1.1 mg/kg methylprednisolone acetate, administered subcutaneously; group 2 received 1 mg/kg per day of prednisone administered orally for three weeks; and group 3 received 2.2 mg/kg per day of prednisone administered orally for seven days. Before the administration of the glucocorticoids the serum concentrations of all the acute phase proteins were within the authors' laboratory reference ranges. After the administration of the drugs there were significant increases in the concentration of haptoglobin in all three groups, the increases being larger in groups 2 and 3. In contrast, the concentrations of C-reactive protein, caeruloplasmin and serum amyloid A were not affected.

Cortisol and free thyroxine determination by time-resolved fluorometry in canine serum

Validation for canine serum of 2 commercially available time-resolved fluoroimmunoassays (TR-FIAs) designed for analysis of cortisol and free thyroxine (fT4) in human serum was carried out. Included was the study of interference by hemolysis, lipemia, and bilirubinemia. With the dissociation enhancement lanthanide fluoroimmunoassay kits, the intra-assay coefficient of variation (CV) ranged from 6.4% to 8.7% for cortisol and from 5.3% to 9.8% for fT4; the interassay CVs ranged from 5.8% to 10.8% and from 3.9% to 14.1%, respectively. Accuracy was evaluated by comparing cortisol and fT4 results obtained with TR-FIA and those obtained with a validated enzyme-linked immunosorbent assay (ELISA) and an equilibrium dialysis (ED) assay, respectively. The regression equations obtained were y = 0.57x + 1.18 (r2 = 0.90) for cortisol and y = 0.87x + 0.82 (r2 = 0.93) for fT4. The limits of detection for cortisol and fT4 were 4.84 nmol/L and 2.68 pmol/L, respectively. The results of adrenocorticotropin-stimulation and dexamethasone-suppression tests were similar to those published previously; likewise, serial dilution of a canine serum sample with a high cortisol content demonstrated that the TR-FIA was immunologically specific. Serial dilution of a serum sample with a high fT4 concentration showed a methodologic bias, a dependence on serum binding capacity, which indicates that the results obtained with this method should be interpreted with caution. Finally, hemolysis and lipemia significantly interfered with cortisol and fT4 measurements, whereas bilirubinemia did not affect the results.