IDEXX Laboratories Research Articles

Diagnostic accuracy of Somaticell, California Mastitis Test, and microbiological examination of composite milk to detect Streptococcus agalactiae intramammary infections

The objectives of this study were to estimate the accuracy of Somaticell (Idexx Laboratories Inc., Westbrook, ME), California Mastitis Test (CMT), and microbiological examination of composite milk (MEC) to diagnose Streptococcus agalactiae intramammary infections (IMI), and to assess the agreement between Somaticell and CMT to detect these infections. A secondary objective was to estimate quarter- and cow-level prevalence of S. agalactiae IMI in the herds included in the study. Seven farms were included in the study. The CMT was performed and aseptic milk samples were collected from all quarters of all lactating cows. Composite milk samples were produced in the laboratory by mixing milk from all quarters of each sampled cow. The Somaticell test was performed on a subset of S. agalactiae-positive (n = 167) and S. agalactiae-negative (n = 152) quarter milk samples. Microbiological examination of quarter milk samples (MEQ) was considered the reference test for diagnosing S. agalactiae IMI. The accuracy of all tests at various thresholds was estimated using Bayesian latent class models. Apparent prevalence of S. agalactiae IMI was 15.8% (n = 184/1,164) at the quarter level (based on MEQ) and 28.5% (n = 83/291) at the cow level (based on MEC). True prevalence, as determined by Bayesian models, was 13.0% [95% credible interval (CR): 6.4-24.4%] at the quarter level, and 25.6% (95% CR: 15.3-39.5%) at the cow level. At the cow level (n = 285), sensitivity and specificity of MEC were 95.6 and 99.5%, respectively. The accuracy of Somaticell (n = 319 quarters) to identify S. agalactiae-infected quarters was 75.4, 86.4, 88.9, 89.4, and 91.0% at thresholds of 98,000, 147,000, 205,000, 244,000, and 282,000 cells/mL, respectively. The accuracy of CMT was 87.6, 90.7, 90.8, and 87.4% at thresholds of trace, 1, 2, and 3, respectively. The areas under the receiver operating characteristic curve for Somaticell and CMT were 94.5% (95% confidence interval: 91.8-97.2%) and 92.0% (88.6-95.4%), respectively. At the tested thresholds, the sensitivity of Somaticell ranged from 94.9 to 99.5% to detect S. agalactiae IMI, and specificity ranged from 48.1 to 87.1%. The sensitivity of Somaticell at the lowest threshold (69,000 cells/mL; sensitivity = 99.9%; 95% CR: 98.2-100%) was higher than that of CMT at any tested threshold. Results of this study could be used at the farm level to reduce the use of antimicrobials and reach specific goals in S. agalactiae eradication programs.

Association of paratuberculosis sero-status with milk production and somatic cell counts across 5 lactations, using multilevel mixed models, in dairy cows

The aim of this work was to investigate associations between individual cow Mycobacterium avium ssp. paratuberculosis (MAP) seropositivity, 305-d corrected milk production, and somatic cell count during 5 lactations lifespan in Portuguese dairy herds using multilevel mixed models. We used MAP serum ELISA (Idexx MAP Ac, Idexx Laboratories Inc., Westbrook, ME) results (n = 23,960) from all the 20,221 adult cows present in 329 farms and corresponding 47,586 lactation records from the National Dairy Improvement Association. Cows and farms were classified as positive or negative. Multilevel mixed models were used to investigate the association of cow MAP status with variation in milk production and somatic cell count. Cow MAP status, farm status, and lactation number were considered as independent variables. A quadratic function of lactation number was used to mimic the effect of lactation order on milk production. The models considered 3 levels: measurement occasion (level 1) within cow (level 2) and cow within farm (level 3). Four final models were produced, including all herds and cows, to address the effect of farm status (models 1 and 2) or the effect of cow status (models 3 and 4) on the outcome variables. Our results show that MAP status affects milk production. Losses are detectable from third lactation onward. During the first 5 lactations, positive cows accumulated an average loss of 1,284.8 kg of milk when compared with the negative cows. We also observed that somatic cell counts were higher in positive cows and a positive interaction occurs between cow status and lactation number, suggesting a positive association between MAP infection and increased somatic cell counts. Our results are in line with previous studies, suggesting a possible positive relation between cow milk production and susceptibility to MAP infection.

Evidence for Clinical Anaplasmosis and Borreliosis in Cats in Maine

The objectives of this study were to use data from client-owned cats in an Ixodes scapularis endemic area to evaluate for clinical associations with diagnostic test results for Anaplasma phagocytophilum and Borrelia burgdorferi and to provide information from a group of cats with possible borreliosis as the cause of clinical manifestations of disease. All cases were evaluated at one clinic, medical records were evaluated, and sera from all cats were tested using one of two commercially available assays labeled for the use with dog sera (SNAP 4Dx or SNAP 4Dx Plus; IDEXX Laboratories, Westbrook, ME). Of the 159 cats evaluated, 42 cats (26.4%) had clinical signs consistent with A. phagocytophilum or B. burgdorferi infection and 117 cats (73.6%) were apparently healthy. Antibodies against B. burgdorferi or A. phagocytophilum were detected in sera of 18.2% and 6.3% of the 159 cats, respectively. Cats with clinical signs of disease were 4 times more likely to have antibodies against one or both agents than healthy cats (95% confidence interval [CI] 1.7928-8.9246; P = .0007), cats allowed outdoors were 5 times more likely to have antibodies against one or both agents than cats housed exclusively indoors (95% CI 2.0196-12.4497; P = .0005), and cats of owners who purchased acaricides were more likely (odds ratio = .3977) to have antibodies against one or both agents than cats of owners who did not purchase acaricides (95% CI .1659-.9534; P = .0387). The cats in the case series were believed to have B. burgdorferi infection as the most likely cause of illness based on serological testing, select clinical information, and apparent response to administration of doxycycline. The results suggest that both A. phagocytophilum and B. burgdorferi are associated with clinical illness in cats. Owners of cats allowed outdoors should be diligent in the use of acaricides.

Q-Fever Antibodies in Romanian Small Ruminants

Small ruminants serum samples from Romanian Counties were investigated by iELISA Q-fever Coxiella burnetii Antibody test kit (IDEXX Laboratories, Liebefeld-Bern, Switzerland), according to the manufacturer’s instructions. In Giurgiu County 10/15 goats serum samples were positive and all sheep samples (6/6) were negative. In Sibiu County 5/75 sheep samples were positive. In Constanta County all goat samples (10/10) were negative. In Braila County all goat samples (95/95) were negative and 10/55 sheep samples were positive. Prevalence of sero-positive results and their distribution does not provide enough data to design a surveillance program, but support the hypothesis of the presence of the pathogen in Braila, Giurgiu and Sibiu Counties. Further studies must be carry on statistically relevant sampling system.

Prevalence and Association of Escherichia coli and Diarrheagenic Escherichia coli in Stored Foods for Young Children and Flies Caught in the Same Households in Rural Bangladesh

.Consumption of contaminated stored food can cause childhood diarrhea. Flies carry enteropathogens, although their contribution to food contamination remains unclear. We investigated the role of flies in contaminating stored food by collecting food and flies from the same households in rural Bangladesh. We selected 182 households with children ≤ 24 months old that had stored foods for later feeding at room temperature for ≥ 3 hours. We collected food samples and captured flies with fly tapes hung by the kitchen. We used the IDEXX Quanti-Tray System (Colilert-18 media; IDEXX Laboratories, Inc., Westbrook, ME) to enumerate Escherichia coli with the most probable number (MPN) method. Escherichia coli–positive IDEXX wells were analyzed by polymerase chain reaction for pathogenic E. coli genes (eae, ial, bfp, ipaH, st, lt, aat, aaiC, stx1, and stx2). Escherichia coli was detected in 61% (111/182) of food samples, with a mean of 1.1 log10 MPN/dry g. Fifteen samples (8%) contained pathogenic E. coli; seven (4%) had enteropathogenic E. coli (EPEC) genes (eae and/or bfp); and 10 (5%) had enteroaggregative E. coli genes (aat and/or aaiC). Of flies captured in 68 (37%) households, E. coli was detected in 41 (60%, mean 2.9 log10 MPN/fly), and one fly (1%) had an EPEC gene (eae). For paired fly-food samples, each log10 MPN E. coli increase in flies was associated with a 0.31 log10 MPN E. coli increase in stored food (95% confidence interval: 0.07, 0.55). In rural Bangladesh, flies possibly a likely route for fecal contamination of stored food. Controlling fly populations may reduce contamination of food stored for young children.

Pseudomonas aeruginosa in Peniche coastal waters

Event Abstract Back to Event Pseudomonas aeruginosa in Peniche coastal waters Adriana P. Januário1*, Clélia N. Afonso1, Susana L. Mendes1 and Maria J. Rodrigues1 1 Polytechnic Institute of Leiria, MARE - Marine and Environmental Sciences Centre, Portugal P. aeruginosa is a ubiquitous organism with minimal requirements for survival and a remarkable ability to adapt to a variety of environmental conditions [1-2]. Members of this species can even survive for months in deionized or distilled water [3]. In the last decades, P. aeruginosa has become one of the most studied bacteria in the public health area due to the fact that a small percentage of strains, demonstrated to be a significant human threat [1]. It is primarily associated with ear, eye and skin infections, causing serious nosocomial infections in cystic fibrosis and burn patients [4-7]. Since the 60’s, that traditional microbiological techniques have been used for the detection and enumeration of P. aeruginosa, mostly the membrane filtration (MF) method, included in the ISO 16266:2006 [8]. Having several limitations, especially the fact that is time consuming, there is an urgent need for the development of alternative methods that overcome the limitations found in conventional methodologies. Pseudalert®/Quanti-Tray® MPN test is a new method, developed by IDEXX Laboratories Inc., which signals the presence of P. aeruginosa in just 24 hours, clearly reducing the time needed to obtain the results. But this methodology is only indicated for tap, pool and drinking water [9-10]. Results showed no significant differences (p-value>0.05) when comparing the new method with the traditional microbiological method, suggesting that Pseudalert®/Quanti-Tray® MPN test can be considered a faster, easier to perform, and safer alternative methodology to assess P. aeruginosa contamination in coastal waters. The major drawback of microbiological methods is the inability to detect viable but non-culturable (VNBC) forms [8]. PCR-based assays have become more attractive, but most authors still use a culture-enrichment step or a short grow step in the culture medium [11-12]. So, we developed a preliminary RT-PCR assay to detect P. aeruginosa without any of these previous steps. The estimated time of the assay was 6 hours, allowing the detection of P. aeruginosa through the amplification of the ecfX gene and using a TZ lysing solution to extract the bacterial genomic DNA of the membrane filters. This assay constitutes a viable alternative to the conventional methodologies, when applied to the detection of P. aeruginosa in seawater samples. Acknowledgements This study had financial support of Fundação para a Ciência e Tecnologia (FCT) through the strategic project UID/MAR/04292/2013 granted to MARE.

Hematological parameters and sorological detection of canine hemoparasitoses with SNAP 4DX

Introduction: The SNAP 4Dx is a rapid test device that uses ELISA (Enzyme-Linked Immunosorbent Assay) technology manufactured by the IDEXX Laboratory (Maine, USA) for rapid diagnosis of hemoparasitosis in dogs. SNAP® ELISA technology utilizes unique conjugate and substrate that amplifies the results. The bidirectional flow process evidences the antigen-antibody binding, providing high sensitivity and reliable results. Objective: evaluation of hematological parameters and serological detection of hemoparasitoses in dogs with Snap 4Dx. Methodology: A cross – sectional, descriptive and observational clinical research was carried out between September 2014 and October 2014 at Pet Dream Veterinary Medical Clinic, located in the city of Recife / PE. The hemogram was performed using a manual technique using blood collected with EDTA. The detection of the antigen of Dirofilaria immitis and the antibodies of Anaplasma phagocytophilum, Anaplasma platys, Borrelia burgdorferi, Ehrlichia canis and Ehrlichia ewingii, was performed with SNAP 4DX Plus device. Results and Discussion: 62 dogs of different races were used, without specifying age or sex, attended at the Clinic. The blood samples were collected by venipuncture cephalic or jugular, according to the size of the animal. The samples were packed in eppendorf microtubes containing EDTA as anticoagulant. The differential count was performed through blood smearing, stained in panopticus, observed with a 100X immersion objective. The rapid test for serological diagnosis showed the following result: Ehrlichia canis (32.25%), Anaplasma platys (6.45%), Dirofilaria immitis (6.45%). Discussion: The results found in the present study suggest that the 4DxPlus Kit was efficient for the diagnosis of hemoparasitoses, which cause diseases in small animals. Conclusion: hematological changes were varied, but thrombocytopenia was the main alteration. The animal with thrombocytopenia may present it silently or start to have symptoms such as: bleeding on the skin; nose bleeds; fever; cough; lethargy; urinary bleeding.

Reliability of symmetric dimethylarginine in dogs with myxomatous mitral valve disease as kidney biomarker.

The most common cause of heart failure in the canine population is myxomatous mitral valve disease, sometimes complicated by chronic kidney disease. Many studies have been done on the use of symmetric dimethylarginine as biomarker of renal impairment in dogs affected by chronic kidney disease, few studies have examined his reliability as biomarker in dogs affected by heart diseases. Aim of this study was to evaluate symmetric dimethylarginine in dogs affected by mitral valve disease in order to assess his reliability in heart diseases. This was a retrospective case-control study on a clinical population of dogs affected by mitral valve disease (cases) vs healthy dogs (controls). Both groups underwent a complete physical evaluation, echocardiographic examination, complete blood count, biochemical panel, including serum creatinine and urea and urine analysis with protein-to-creatinine ratio. Serum was frozen and sent to IDEXX laboratories for symmetric dimethylarginine determination. General linear model was applied to data. A total number of 24 cases and 7 controls were included. Symmetric dimethylarginine value was in the reference value in the 75% (n=18) of cases, and in the 43% (n=3) of controls. Once set symmetric dimethylarginine as dependent variable, no statistical significant differences were found for each variable considered (breed, age, sex, weight, class of cardiomyopathy, presence/absence of valvular disease, presence/absence of congestive heart failure, pharmacological therapy, creatinine and urea concentration). Blood concentration of SDMA resulted not influenced by the variables mentioned above, so it could be considered a reliable marker of early renal impairment in dogs affected by mitral valve disease.

Antibiotic residues in pasteurized and unpasteurized milk marketed in southwest of Paraná, Brazil

ABSTRACT: The treatment of dairy cattle with antibiotics may lead to milk contamination by drugs residues, which represents risks to human health. This study aimed to investigate the presence of antibiotic residues in milk, produced and marketed in Capanema microregion, Paraná, Brazil, through the analysis of pasteurized milk samples from different brands consumed by the local population and unpasteurized milk samples provided by a dairy industry. Enzyme immunoassays screening kits SNAPduo™ Beta-Tetra ST Test (Idexx Laboratories) were used, which verified the presence of β-lactam and tetracyclic drugs residues, as well as enzyme immunoassays screening kits Charm ROSA Test (Charm Sciences), which established the presence of quinolones and sulfonamides groups. Positive samples were reported for the four different classes of drugs, demonstrating failures in the inspection and monitoring of the sanitary and chemistry quality of the milk. Results obtained will form the basis to building a database about the quality of milk produced and marketed in the region, as well as the use of these materials to build up an initial theoretical framework for the development of research in animal health and public policies focused on the milk producers and dairy industry, to improve the quality of the milk produced.

Evaluation of 3 Serological Tests for Early Detection Of Leptospira-specific Antibodies in Experimentally Infected Dogs.

BackgroundLeptospirosis in dogs is a disease of global importance. Early detection and appropriate therapeutic intervention are necessary to resolve infection and prevent zoonotic transmission. However, its diagnosis is hindered by nonspecific clinical signs and lack of rapid diagnostic tests of early infection. Recently, 2 rapid point‐of‐care tests (WITNESS Lepto [WITNESS Lepto, Zoetis LLC, Kalamazoo, MI, USA] and SNAP Lepto [SNAP Lepto, IDEXX Laboratories, Westbrook, ME, USA]) for detection of Leptospira‐specific antibodies in canine sera were developed.HypothesisImmunoglobulin M‐based WITNESS Lepto containing multiple detection antigens can detect Leptospira‐specific antibodies to common leptospiral serovars earlier in the course of infection as compared to microscopic agglutination test (MAT) and SNAP Lepto.AnimalsFour groups of 8 6‐ to 8‐month‐old male Beagle dogs were used.MethodsThirty‐two healthy seronegative dogs were inoculated experimentally with serovars Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona (8 dogs/serovar). Acute‐phase sera were collected at regular intervals and monitored for Leptospira‐specific antibodies by WITNESS Lepto, MAT, and SNAP Lepto.ResultsSeroconversion was detected in all dogs by day 10 by WITNESS Lepto and in 30 of 32 dogs by day 14 by MAT. The SNAP Lepto test detected seroconversion in 3 dogs during the 2 weeks postchallenge.ConclusionsImmunoglobulin M‐based WITNESS Lepto detected immune responses specific to multiple leptospiral serovars early in the course of infection and identified seroconversion in all animals earlier than did the gold standard MAT. The SNAP Lepto test displayed considerably lower and inconsistent performance during the study period. At the point‐of‐care, WITNESS Lepto should be the test of choice for rapid and reliable screening of acutely ill dogs suspected to have leptospirosis.

Evaluation of Dirofilaria immitis antigen detection comparing heated and unheated serum in dogs with experimental heartworm infections

BackgroundTo evaluate whether heated serum allows for earlier detection of Dirofilaria immitis antigen, dogs with experimental D. immitis infections underwent weekly blood sampling to compare antigen results using both heated and unheated serum.MethodsOne of two isolates (JYD-34 or Big Head™) were used to infect naïve laboratory beagle dogs. Serum was collected from dogs weekly and divided into two aliquots, heated and unheated. The samples designated as heated were placed in a heat block at 104 °C for 10 min then centrifuged with collection of the resulting supernatant. Two commercial ELISAs, DiroCHEK® (Synbiotics Corporation, Zoetis) and PetChek® (IDEXX Laboratories, Inc.), were used to conduct D. immitis antigen testing on all serum samples.ResultsThere was no statistical difference in the mean number of days from infection to positive D. immitis antigen status between the two commercial testing kits (DiroCHEK® versus PetChek®) with either heated or unheated serum. When unheated serum was utilized, very strong agreement between the two assays was demonstrated using Lin’s concordance correlation coefficient (Rc = 0.98). However, when heated serum was compared, Lin’s concordance correlation coefficient was only Rc = 0.64, showing a lesser agreement. There was a statistical difference in the mean number of days from infection to a positive test result for unheated serum when compared to mean days to positive status with heated serum. For DiroCHEK® the heated serum yielded a positive result 126.9 ± 18.9 days postinfection while the unheated serum yielded a positive result 162.6 ± 23.0 days postinfection; this was a significant 35.7 ± 32.2 days longer, on average, compared with heated serum. With PetChek® the heated serum yielded a positive result 131.5 ± 11.7 days postinfection while the unheated serum yielded a positive result 162.8 ± 23.8 days postinfection; this was a significant 31.3 ± 25.5 days longer, on average, compared with heated serum. The detection of D. immitis antigen earlier using heated serum was consistent for both heartworm isolates.ConclusionOur results suggest heat treatment of serum may allow earlier detection of D. immitis antigen but with less consistency demonstrated across two testing platforms as compared with antigen detection using unheated serum.

Comparative evaluation of commercially available point-of-care heartworm antigen tests using well-characterized canine plasma samples

BackgroundDirofilaria immitis is a worldwide parasite that is endemic in many parts of the United States. There are many commercial assays available for the detection of D. immitis antigen, one of which was modified and has reentered the market. Our objective was to compare the recently reintroduced Witness® Heartworm (HW) Antigen test Kit (Zoetis, Florham Park, NJ) and the SNAP® Heartworm RT (IDEXX Laboratories, Inc., Westbrook, ME) to the well-based ELISA DiroChek® Heartworm Antigen Test Kit (Zoetis, Florham Park, NJ).MethodsCanine plasma samples were either received at the Auburn Diagnostic Parasitology Laboratory from veterinarians submitting samples for additional heartworm testing (n = 100) from 2008 to 2016 or purchased from purpose-bred beagles (n = 50, presumed negative) in 2016. Samples were categorized as “positive,” “borderline” or “negative” using our established spectrophotometric cutoff value with the DiroChek® assay when a sample was initially received and processed. Three commercially available heartworm antigen tests (DiroChek®, Witness® HW, and SNAP® RT) were utilized for simultaneous testing of the 150 samples in random order as per their package insert with the addition of spectrophotometric optical density (OD) readings of the DiroChek® assay. Any samples yielding discordant test results between assays were further evaluated by heat treatment of plasma and retesting. Chi-square tests for the equality of proportions were utilized for statistical analyses.ResultsConcordant results occurred in 140/150 (93.3%) samples. Discrepant results occurred in 10/150 samples tested (6.6%): 9/10 occurring in the borderline heartworm (HW) category and 1/10 occurring in the negative HW category.The sensitivity and specificity of each test compared to the DiroChek® read by spectrophotometer was similar to what has been reported previously (Witness®: sensitivity 97.0% [94.1–99.4%], specificity 96.4% [95.5–100.0%]; SNAP® RT: sensitivity 90.9% [78.0–100.0%], specificity 98.8% [96.0–100.0%]). There were significant differences detected when comparing the sensitivities of the SNAP® RT and the Witness® HW to the DiroChek® among the 150 total samples (p = 0.003) and the 50 “borderline” samples (p = 0.001).ConclusionsIn this study, the sensitivity of the Witness® HW was higher than the sensitivity of the SNAP® RT when compared with the DiroChek® test results prior to heat treatment of samples.

Validation of immune complex dissociation methods for use with heartworm antigen tests

BackgroundAntigen testing is routinely used to diagnose canine Dirofilaria immitis infections. Immune complex dissociation (ICD) methods, which were employed in the original heartworm antigen tests to release antigen that was bound by endogenous canine antibodies, were discontinued with improvements in assay reagents. The purpose of this study was to evaluate different ICD methods for detection of heartworm antigen by microtiter plate ELISA and assess the performance in samples from pet dogs.MethodsThe original PetChek® Heartworm Test (IDEXX Laboratories, Inc.) utilized pepsin at an acidic pH for ICD prior to antigen testing. Performance and characteristics of the pepsin ICD method were compared with those for heat treatment (with and without EDTA) and acid treatment.ResultsAll four methods released complexed antigen in serum samples when tested using microtiter plate ELISA. Heat treatment required ≥600 μL of serum or plasma, whereas pepsin and acid methods needed only a 50-μL sample. Samples from 1115 dogs submitted to IDEXX Laboratories between 2014 and 2016 for investigation of discrepant heartworm results were evaluated with and without pepsin ICD using the PetChek Heartworm Test. Samples from 10% (n = 112) of the dogs were antigen positive with the ICD protocol only while 90% of the results remained unchanged. In a prospective study, antigen levels with and without ICD were evaluated for 12 dogs receiving pre-adulticide heartworm treatment with a macrocyclic lactone and doxycycline for 28 days. Serial samples revealed that three dogs had a reduction in detectable heartworm antigen within 4 weeks of initiating treatment. In these cases, heartworm antigen levels could be recovered with ICD.ConclusionsHeartworm antigen testing with ICD can be a valuable diagnostic tool for patients with discrepant results that have had intermittent use of a preventive, or have been treated with a macrocyclic lactone and doxycycline. Heartworm therapies may reduce antigen production and favor immune complexing in some dogs, resulting in false-negative results. Therefore, it is important to confirm positive heartworm antigen test results before initiating therapy.

Short communication: Relationship between methods for measurement of serum electrolytes and the relationship between ionized and total calcium and neutrophil oxidative burst activity in early postpartum dairy cows

The objectives of this study were to (1) compare a test for serum measurement of total Ca (tCa), Mg, and P (VetTest Chemistry Analyzer, IDEXX Laboratories Inc., Westbrook, ME) to reference methods (spectrophotometric assays on a Beckman Coulter 640e automated clinical chemistry analyzer; Beckman Coulter, Brea, CA), (2) determine the relationship between ionized Ca (iCa) and reference method tCa in the immediate postpartum period, and (3) assess the relative value of these blood Ca indices as predictors of neutrophil oxidative burst activity. Samples were collected from multiparous Holstein cows (n = 33) over the first 5 d in milk. A total of 183 samples for objective 1 and 181 samples for objective 2 were available. Neutrophil oxidative burst activity was assessed once between 2 and 5 d in milk (n = 29). Linear regression demonstrated strong relationships between serum tCa, Mg, and P concentrations measured by the VetTest compared with the reference method. Bland Altman analysis indicated that the VetTest values were higher than the reference method by 0.22 mmol/L for tCa, 0.12 mmol/L for Mg, and 0.16 mmol/L for P. Compared with hypocalcemia categorized at ≤2.0 or ≤2.125 mmol/L with the reference method tCa, thresholds for the VetTest measured tCa of ≤2.23 mmol/L (sensitivity = 87%, specificity = 89%) or ≤2.30 mmol/L (sensitivity = 86%, specificity = 96%) could be used. The relationship between whole-blood iCa and reference method serum tCa differed by sampling time point after calving. Compared with identification of hypocalcemia with serum tCa measurements from the reference method (thresholds of ≤2.0 and 2.125 mmol/L), a whole-blood iCa threshold of ≤1.17 mmol/L resulted in the highest combined sensitivities (94 and 82%) and specificities (80 and 94%) at either threshold. Ionized Ca measurements were more consistently related to outcomes of neutrophil oxidative burst activity measured in vitro. The VetTest measurements of serum tCa reliably identified hypocalcemia when thresholds were adjusted to account for the bias of the test. The variation in the relationship between iCa and reference method tCa in the days following parturition suggest that these measures cannot be used interchangeably as indicators of Ca status. The more consistent associations between iCa and in vitro measures of neutrophil function, compared with tCa, indicated that this may be a more sensitive predictor of functional outcomes associated with postpartum Ca status.

Plasma Symmetric Dimethylarginine Concentration in Dogs with Acute Kidney Injury and Chronic Kidney Disease.

BackgroundSymmetric dimethylarginine (SDMA) is considered a biomarker for early detection of renal dysfunction in human patients with acute kidney injury (AKI). At present, no studies exist analyzing the relevance of SDMA in dogs with AKI.Hypothesis/objectives SDMA would correctly identify dogs with renal disease but would not be able to differentiate between AKI and CKD.AnimalsEighteen healthy control dogs, 48 dogs with AKI, and 29 dogs with CKD.MethodsProspective study. Dogs with kidney disease were categorized as having AKI or CKD according to the history, clinical signs, laboratory findings, and results of diagnostic imaging. Plasma SDMA concentration was measured by IDEXX Laboratories. SDMA/creatinine ratio was calculated in dogs with AKI or CKD.ResultsMedian SDMA concentrations were 8.5 μg/dL (6–12 μg/dL), 39.5 μg/dL (8–>100 μg/dL), and 35 μg/dL (12–>100 μg/dL), in healthy, AKI, and CKD, respectively. SDMA concentrations were significantly higher in dogs with AKI (P < .0001) or CKD (P < .0001) in comparison with healthy dogs. Median SDMA/creatinine ratio in dogs with AKI and CKD was 6.5 (1.7–20.9) and 10 (2.4–33.9) (P = .0004), respectively. Although there was overlap of the SDMA/creatinine ratio in dogs with AKI or CKD, it was significantly higher in dogs with CKD compared to dogs with AKI (P = .0004).Conclusions and Clinical ImportanceIn this population, SDMA was suitable for identifying dogs affected by AKI or CKD, but could not differentiate between them.

Seroprevalence of foot-and-mouth disease in large ruminants in periurban dairy farms near Islamabad, Pakistan

Abstract Background Foot-and-mouth disease (FMD) is an enzootic viral disease affecting livestock in Pakistan. Objectives To determine the seroprevalence of FMD in large ruminants in periurban dairy farms near Islamabad. Methods Serum samples were collected from 636 large ruminants during 2011 to 2012; 584 (92%) were buffaloes (Bos bubalis bubalis) and 52 (18%) were cattle (Bos taurus indicus). The population sampled was mainly adult (n = 514) and female (n = 596). Sera were assayed for antibodies against a nonstructural protein of the FMD virus using a Chekit FMD-3ABC bo-ov enzyme immunoassay Kit (Idexx Laboratories). Data were analyzed using a χ2 test and multiple logistic regression. Results The seroprevalence of FMD in the ruminants was 46% (n = 293, 95% confidence interval (CI); 42.18- 49.95) and was significantly higher in buffaloes (285, 97%; χ2 = 21.46; P &lt; 0.001) than in cattle (8, 3%). The risk of seropositivity increased significantly with age (χ2 = 72.71; P &lt; 0.001); adult animals were 7.05 times more likely (odds ratio (OR) 7.05, 95% CI 3.60-13.79; P &lt; 0.001) to be seropositive after adjusting for the effect of species. Buffaloes were more likely to be seropositive (OR 3.99, 95% CI 1.78-8.92, P = 0.001). Sex was not significantly associated with FMD seropositivity (OR 0.58, 95% CI 0.17-1.95, P = 0.38). Conclusions Large ruminants in periurban dairy farms near Islamabad have a high FMD virus seroprevalence and play a potential role in the persistence and transmission of FMD in Pakistan.

Performance of the Angio Detect™ in-clinic test kit for detection of Angiostrongylus vasorum infection in dog samples from Europe

Angiostrongylosis is a crucial differential diagnosis in any dog with respiratory, bleeding, neurological, or syncopal signs of unknown etiology in endemic areas. Many cases of angiostrongylosis have a fatal outcome; subclinical angiostrongylosis also has been reported. The most common method for supporting diagnosis of angiostrongylosis has been identification of Angiostrongylus vasorum first stage larvae in the feces by the Baermann-Wetzel method. Although considered as gold standard, this method has technical and sampling challenges and cannot detect infections during prepatency or in case of intermittent shedding of the larvae. A rapid in-clinic antigen test has been developed for serologic detection of A. vasorum infections using blood samples (Angio Detect™, IDEXX Laboratories Inc., Westbrook, Maine, USA). The study reported here was conducted to determine diagnostic sensitivity and specificity of the Angio Detect test kit by comparing Angio Detect testing results using serum or plasma samples with the results of Baermann-Wetzel testing using matched fecal samples. Samples from 214 dogs [with clinically suspected (N=195) or diagnosed angiostrongylosis (N=19)] were used for this evaluation. Baermann-Wetzel testing was performed independently at commercial reference laboratories or at university hospitals. All serum/plasma samples were blinded and randomized before testing with Angio Detect. The Angio Detect test was positive for 34 of the 35 cases found positive by the Baermann-Wetzel method; sensitivity of the Angio Detect test was 97.1% (95%CI: 85.1%–99.9%). The Angio Detect test was negative for 177 of 179 samples that were negative by the Baermann-Wetzel test; specificity was 98.9% (95%CI: 96.0%–99.9%). In cross-reactivity testing, all 89 samples from dogs confirmed to be infected with other common nematodes (Dirofilaria immitis, D. repens, Crenosoma vulpis, hookworms, ascarids, or whipworms) were all negative for A. vasorum by the Angio Detect antigen test. Angio Detect provides a rapid and reliable method for diagnosis of A. vasorum in clinically suspected dogs at risk for infection. The test requires minimal steps by the operator and provides results in 15min, allowing the clinician to initiate treatment for positive dogs before leaving the clinic.

In this issue - September 2016: Portable negative pressure wound therapy for skin grafts in dogs · Wellness testing in small animals · Effects of pimobendan on myocardial perfusion and pulmonary transit time in dogs · Rispens CVI988 vaccine virus and Marek's disease virus in poultry · A field study of ovulation in oestrus mares · Post-weaning growth of beef

In this issue - September 2016: Portable negative pressure wound therapy for skin grafts in dogs · Wellness testing in small animals · Effects of pimobendan on myocardial perfusion and pulmonary transit time in dogs · Rispens CVI988 vaccine virus and Marek's disease virus in poultry · A field study of ovulation in oestrus mares · Post-weaning growth of beef

Molecular identification of Giardia duodenalis isolates from domestic dogs and cats in Wroclaw, Poland.

Giardia duodenalis (G. intestinalis) is a common protozoan causing gastrointestinal disorders in many species of mammals. The genus of Giardia has high molecular diversity. Dogs and cats, in addition to their typical infection with assemblages C, D and F, may be a reservoir of zoonotic assemblages (A and B). The aim of this study was a genetic characteristic of Giardia isolates of dogs and cats from the area of Wroclaw (Poland). A total of 128 and 33 faecal samples from dogs and cats, respectively, were analyzed by routine coprological methods. The animals were diagnosed on the presence of G. duodenalis antigens in faeces soluble with the use of SNAP Giardia (IDEXX Laboratories) immunosorbent assay. 27 DNA isolates of Giardia were subjected to molecular identification (PCR-RFLP). The prevalence of G. duodenalis was 21.1% (27/128) in dogs and 15.1% (5/33) in cats. In dogs, C assemblage was present in 18 (81%) positive stool samples, D assemblage in 2 (9%) samples, B assemblage present in one (4.5%), and mixed assemblages (C and D) occurred in one (4.5%) sample. F assemblage was found in 4 (80%) cats' positive stool samples and A assemblage occurred in one case (20%). Confirmation of the presence of A and B zoonotic assemblages suggests that infected pets can be a threat to human health. This study describes for the first time the presence of mixed infections within host-specific C and D assemblages in dogs in Poland.

Evaluation of rapid diagnostic test kits for feline leukemia virus infection using samples from naturally infected cats.

ObjectivesFeline leukemia virus (FeLV) is a potentially life-threatening oncogenic retrovirus. The p27 viral core protein is produced by the virus in infected feline cells, is found in the cytoplasm in several blood cells and can be free in the serum and plasma. ELISA or particle-based immunoassay are commonly used to detect the presence of the p27 core protein in samples obtained from blood. The objective of this study was to compare the performance of several in-clinic tests: the SNAP Feline Triple Test (IDEXX Laboratories), the WITNESS FeLV-FIV Test (Zoetis) and the VetScan Feline FeLV/FIV Rapid Test (Abaxis).MethodsThe sample population (100 positive, 105 negative samples) consisted of serum and plasma samples submitted to IDEXX’s worldwide reference laboratory for feline retrovirus testing. Virus isolation and reverse transcriptase PCR results were not available and so samples were judged to be positive or negative based on the results of the ViraCHEK FeLV (Zoetis) microtiter plate assay.ResultsThe percentage of samples positive and negative for FeLV p27 antigen using the three in-clinic tests compared with the ViraCHEK method were as follows: IDEXX Feline Triple (positive 98.0%, negative 100%); Zoetis WITNESS (positive 79.0%, negative 97.1%); Abaxis VetScan (positive 73.0%, negative 97.1%).Conclusions and relevanceThe SNAP Feline Triple Test demonstrated a high level of agreement for FeLV-positive and FeLV-negative samples when assessed in this model. Results of FeLV assays can vary among tests.