BackgroundThe sensitivity, specificity, and agreement of 4 diagnostic assays (SNAP canine pancreatic lipase (cPL), specific cPL (Spec cPL), VetScan cPL Rapid Test, and Precision PSL) for pancreatitis in dogs have not been directly compared.Hypothesis/ObjectivesTo determine the level of agreement among each of the 4 assays and a clinical suspicion score, level of agreement among the assays, and sensitivity and specificity of each assay in a clinically relevant patient group.AnimalsFifty client‐owned dogs with clinical signs of gastrointestinal disease.MethodsProspective study. History, physical examination, complete blood count, serum biochemistry, abdominal ultrasound examination, and the 4 diagnostic assays for pancreatitis were performed. Intraclass correlation coefficients (ICC) were used to determine the level of agreement between each assay and a clinical suspicion score determined by a panel of 5 board‐certified veterinary internists.ResultsThe ICC between the clinical suspicion score and the 4 assays were SNAP cPL, 0.61; Spec cPL, 0.68; VetScan cPL Rapid Test, 0.68; and Precision PSL, 0.60. The sensitivities of the assays ranged from 73.9 to 100.0%, whereas the specificities were SNAP cPL, 71.1–77.8%; Spec cPL, 74.1–81.1%; VetScan cPL Rapid Test, 76.9–83.8%; and Precision PSL, 64.0–74.3%.Conclusions and Clinical ImportanceA good to excellent level of agreement was demonstrated among the 4 assays. The previously unreported sensitivity and specificity of the VetScan cPL Rapid Test were 73.9–83.3% and 76.9–83.8%, respectively. Results of any of the 4 diagnostic assays alone, in the absence of supporting clinical findings, are insufficient to establish a diagnosis of clinical pancreatitis in dogs.

Cyclosporine is an immunomodulatory drug used to treat an increasing spectrum of diseases in dogs. Cyclosporine is a calcineurin inhibitor, ultimately exerting its inhibitory effects on T‐lymphocytes by decreasing production of cytokines, such as interleukin‐2. Although, in the United States, oral cyclosporine is approved in dogs only for treatment of atopic dermatitis, there are many other indications for its use. Cyclosporine is available in 2 oral formulations: the original oil‐based formulation and the more commonly used ultramicronized emulsion that facilitates oral absorption. Ultramicronized cyclosporine is available as an approved animal product, and human proprietary and generic preparations are also available. Bioavailability of the different formulations in dogs is likely to vary among the preparations. Cyclosporine is associated with a large number of drug interactions that can also influence blood cyclosporine concentrations. Therapeutic drug monitoring (TDM) can be used to assist in attaining consistent plasma cyclosporine concentrations despite the effects of varying bioavailability and drug interactions. TDM can facilitate therapeutic success by guiding dose adjustments on an individualized basis, and is recommended in cases that do not respond to initial oral dosing, or during treatment of severe, life‐threatening diseases for which a trial‐and‐error approach to dose adjustment is too risky. Pharmacodynamic assays that evaluate individual patient immune responses to cyclosporine can be used to augment information provided by TDM.

Background: Pharmacodynamic assays measure the immunosuppressive effects of cyclosporine on T-cells and offer an alternative assessment of efficacy in individual patients.Objective: To assess the immunosuppressive effects of high and low dosage cyclosporine on canine T-cells and to develop a novel testing system for individualized dose adjustment.Animals: Seven healthy female Walker hounds. Methods: Experimental study using a paired comparison design. Flow cytometry was used to measure T-cell expression of IL-2, IL-4, and IFN-c. Cytokine expression 8 days after oral administration of high and low dosages of cyclosporine was compared to baseline and washout values, respectively. The high dosage was initially 10 mg/kg q12h and was then adjusted to attain established immunosuppressive trough blood drug concentrations (>600 ng/mL). The low dosage was 5 mg/kg q24h.Results: High dosage cyclosporine resulted in significant decreases in IL-2 and IFN-c expression (P = .0156, P = .0156), but not IL-4 expression (P = .2188). Low dosage cyclosporine was associated with a significant decrease in IFN-c expression (P = .0156), while IL-2 expression was not affected (P = .1094).Conclusions and Clinical Importance: T-cell function is suppressed at trough blood drug concentrations exceeding 600 ng/mL, and is at least partially suppressed in some dogs at low dosages. Direct evaluation of T-cell function could be an effective, more sensitive alternative to measuring blood drug concentrations for monitoring immunosuppressive therapy.

Laryngeal dysfunction induced by gastroesophageal reflux as occurred in the patient described in this report is a previously undocumented association in the veterinary literature. This association could be a potential consideration in dogs with concurrent respiratory and gastrointestinal signs. The present report may provide a basis for further studies investigating this association.

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Title of Study: Effects of aspirin dose escalation on platelet function and urinary thromboxane and prostacyclin levels in normal dogs Pages in Study: 75Candidate for Degree of Master of Science Eight dogs were enrolled in a randomized, cross-over study that used optical aggregometry and a platelet function analyzer to evaluate platelet function before and after the administration of 5 aspirin dosages: 0.5 mg/kg q24h, 1 mg/kg q24h, 2 mg/kg q24h, 4 mg/kg q24h and 10 mg/kg q12h. Urine 11-dehydro-thromboxane-B2 (11-dTXB2) and 6-keto-prostaglandin-F1alpha (6-keto-PGF1alpha), were measured. Compared to pretreatment, there were significant decreases in maximum aggregometry amplitude and increases in PFA-100 closure times for all doses except 0.5 mg/kg q24h. There was no difference in amplitude or closure time between the 2 mg/kg, 4 mg/kg, and 10 mg/kg q12h dosages. At 2 mg/kg q24h, 100 percent (aggregometry) of dogs were aspirin responders. There was a significant decrease in urinary 11-dTXB2-and 6-keto-PGF1alpha-to-creatinine ratios with aspirin administration. An aspirin dosage of 2 mg/kg q24h consistently inhibits platelet function in healthy dogs without decreasing prostacyclin synthesis significantly more than lower aspirin dosages.ii DEDICATION I would like to dedicate this research to my parents,

Cyclosporine is an immunosuppressive agent that inhibits T-cell function by decreasing production of cytokines such as interleukin-2 (IL-2) and interferon-γ (IFN-γ). In dogs, there is currently no reliable analytical method for determining effective cyclosporine dosages in individual patients. Our laboratory has developed a quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR) assay that measures IL-2 and IFN-γ gene expression, with the goal of quantifying immunosuppression in dogs treated with cyclosporine. This study focuses on analytical validation of our assay, and on the effects of sample storage conditions on cyclosporine-exposed samples. Heparinized whole blood collected from healthy adult dogs was exposed to a typical post-treatment blood concentration for cyclosporine (500 ng/ml) for 1 hour, and then stored for 0, 24, and 48 hours at both room temperature and 4°C. The study was then repeated using a cyclosporine concentration of 75 ng/ml, with sample storage for 0, 24, and 48 hours at 4°C. Cytokine gene expression was measured using RT-qPCR, and assay efficiency and inter- and intra-assay variability were determined. Storage for up to 24 hours at room temperature, and up to 48 hours at 4°C, did not significantly alter results compared to samples that were processed immediately. Validation studies showed our assay to be highly efficient and reproducible and robust enough to be feasible under standard practice submission conditions.

The duration of immunosuppressive effects following oral cyclosporine in dogs is unknown. This study used flow cytometry and quantitative reverse transcription–polymerase chain reaction (qRT-PCR) to evaluate the effects of high-dose oral cyclosporine across a 12-h dosing interval. Expression of interleukin-2 (IL-2) and interferon-gamma (IFN-γ) was compared before and after 8 days of cyclosporine at 10 mg/kg every 12 h in six healthy dogs. Samples were collected at 0, 2, 4, and 8 h postdosing for analysis of unactivated and activated T-cell and whole blood cytokine expression using flow cytometry and qRT-PCR, respectively, and at 0, 2, 4, 6, 8, and 10 h postdosing for measurement of cyclosporine concentrations. Flow cytometry and qRT-PCR both demonstrated significant marked reductions in IL-2 and IFN-γ levels at 0, 2, 4, and 8 h after dosing compared to pretreatment levels (P < 0.05) for activated samples, with less consistent effects observed for unactivated samples. Both flow cytometry and qRT-PCR are viable techniques for measuring cyclosporine pharmacodynamics in dogs, yielding comparable results with activated samples. Two hours postdrug administration is the preferred time for concurrent assessment of peak drug concentration and cytokine expression, and T-cell activation is needed for optimal results.