Elizabeth G. Welles

Seroprevalence of Ehrlichia canis, Ehrlichia chaffeensis and Ehrlichia ewingii in dogs in North America

BackgroundThis study evaluated the exposure of dogs to three different Ehrlichia spp. in the south and central regions of the United States where vector-borne disease prevalence has been previously difficult to ascertain, particularly beyond the metropolitan areas.MethodsDog blood samples (n = 8,662) were submitted from 14 veterinary colleges, 6 private veterinary practices and 4 diagnostic laboratories across this region. Samples were tested for E. canis, E. chaffeensis and E. ewingii specific antibodies using peptide microtiter ELISAs.ResultsOverall, E. canis, E. chaffeensis and E. ewingii seroprevalence was 0.8%, 2.8%, and 5.1%, respectively. The highest E. canis seroprevalence (2.3%) was found in a region encompassing Arkansas, Louisiana, Oklahoma, Tennessee and Texas. E. chaffeensis seroreactivity was 6.6% in the central region (Arkansas, Kansas, Missouri, and Oklahoma) and 4.6% in the southeast region (Georgia, Maryland, North Carolina, South Carolina, Tennessee and Virginia). Seroreactivity to E. ewingii was also highest in the central region (14.6%) followed by the southeast region (5.9%). The geospatial pattern derived from E. chaffeensis and E. ewingii seropositive samples was similar to previous reports based on E. chaffeensis seroreactivity in white-tailed deer and the distribution of human monocytic ehrlichiosis (HME) cases reported by the CDC.ConclusionsThe results of this study provide the first large scale regional documentation of exposure to E. canis, E. chaffeensis and E. ewingii in pet dogs, highlighting regional differences in seroprevalence and providing the basis for heightened awareness of these emerging vector-borne pathogens by veterinarians and public health agencies.

Canine complete blood counts: a comparison of four in-office instruments with the ADVIA 120 and manual differential counts

BACKGROUND With more use of bench-top in-office hematology analyzers, the accuracy of reported values is increasingly important. Instruments use varied methods for cell counting and differentiation, and blood smears may not always be examined. OBJECTIVE The purpose of this study was to compare canine CBC results using 4 bench-top instruments (Hemavet 950, Heska CBC-Diff, IDEXX LaserCyte, and IDEXX VetAutoread) with ADVIA 120 and manual leukocyte counts. METHODS EDTA-anticoagulated canine blood samples (n=100) were analyzed on each instrument. Manual differentials were based on 100-cell counts. Linear regression, difference plots, paired t-tests, and estimation of diagnostic equivalence were used to analyze results. RESULTS Correlations of HCT, WBC, and platelet counts were very good to excellent between all in-office instruments and the ADVIA 120, but results varied in accuracy (comparability). Hemavet 950 and Heska CBC-Diff results compared best with ADVIA results and manual leukocyte differentials. HCT and platelet counts on the IDEXX VetAutoread compared well with those from the ADVIA. Except for neutrophil counts, leukocyte differentials from all instruments compared poorly with ADVIA and manual counts. Reticulocyte counts on the LaserCyte and VetAutoread compared poorly with those from the ADVIA. CONCLUSIONS The Hemavet 950 and Heska CBC-Diff performed best of the 4 analyzers we compared. HCT, WBC, and platelet counts on the LaserCyte had minimally sufficient comparability for diagnostic use. Except for neutrophils (granulocytes), leukocyte differential counts were unreliable on all in-office analyzers. Instruments with a 5-part leukocyte differential provided no added benefit over a 3-part differential. Assessment of erythrocyte regeneration on the LaserCyte and VetAutoread was unreliable compared with the ADVIA 120.

Antithrombotic and Fibrinolytic Factors: A Review

Excessive or nonphysiologic thrombogenesis and fibrinolysis accompanies many diseases. Several specific proteins involved in the physiologic regulation and maintenance of blood in a fluid state are reviewed in this article. Assays for these proteins or evidence of their function (antithrombin III, protein C, protein S, plasminogen/plasmin, tissue plasminogen activator, plasminogen activator inhibitor I, fibrinogen/fibrin degradation products, and thrombin/antithrombin complexes) are described. Principles, general methodology, and application in veterinary medicine are discussed. Although most of the investigative work and knowledge concerning these proteins and assays has been in human beings, their use and application in veterinary medicine is becoming more available in research laboratories at referral centers and some larger commercial veterinary laboratories. Use and interpretation of these assays will help clinicians and researchers better understand pathophysiologic processes occurring in various diseases associated with thrombogenesis and excessive fibrinolysis.

Automated In-Clinic Hematology Instruments for Small Animal Practitioners: What is Available, What Can They Really Do, and How Do I Make a Choice?

To have an in-clinic hematology instrument in your practice and how it is used are decisions that precede the purchase of an instrument. Advantages and limitations of the various instruments should be considered. Initial purchase cost, reagent/disposable costs, costs of training personnel in the use and care of the instrument, and service/repair contract costs need to be considered. Once the decision is made to have an in-office hematology instrument in your practice you should benefit from having nearly immediate CBC data results that enable you to provide better quality medicine, more rapid clinical decisions, more closely monitor patients for complications of disease or response to treatment. It should also generate revenue and allow some of your staff members to expand and develop their technical skills as they learn the nuances of a new diagnostic tool and how to provide you with the most accurate CBC information. In the final assessment, the addition of an in-office hematology instrument should improve the quality and efficiency of the medical care you provide patients and generate additional practice income.