Diagnostic contribution of individual components of adrenal function tests to diagnose canine hyperadrenocorticism.

There is limited information regarding the value of constitutive components of the ACTH stimulation test (ACTHST) and low-dose dexamethasone suppression test (LDDST) including serum baseline cortisol (BC), difference between post-ACTH stimulation cortisol (PC) and BC (ΔACTHC), cortisol concentration 4h after dexamethasone administration (4HC), difference between 4HC and BC (Δ4C), and the difference between cortisol concentration 8h after dexamethasone administration and 4HC (Δ8C). Therefore, the objective of this study was to determine if these components can predict hyperadrenocorticism, pituitary-dependent hyperadrenocorticism (PDH), or functional adrenocortical tumor (FAT) in dogs. Cortisol concentrations were normalized, as fold change (FC), to the PC reference interval upper limit. A total of 1267 dogs were included, with hyperadrenocorticism diagnosed in 537 (PDH, n=356; FAT, n=28; undetermined, n=153) and excluded in 730. The area under the receiver operating curves for BC, ΔACTHC, 4HC, Δ4C, and Δ8C to predict hyperadrenocorticism were 0.76 (95% confidence interval (CI), 0.73-0.79), 0.91 (95% CI, 0.89-0.93), 0.83 (95% CI, 0.80-0.87), 0.55 (95% CI, 0.50-0.60), and 0.67 (95% CI, 0.62-0.72), respectively. A diagnostic limit of ≥0.78 FC for ΔACTHC had excellent sensitivity (1.00; 95% CI, 0.74-1.00), but poor specificity (0.67; 95% CI, 0.64-0.71), to predict FAT in dogs with a positive ACTHST. A diagnostic limit of ≥-0.26 FC for Δ4C had excellent sensitivity (1.00; 95% CI, 0.79-1.00), but poor specificity (0.21; 95% CI, 0.18-0.26), to predict FAT in dogs with a positive LDDST. In hyperadrenocorticoid dogs that have positive ACTHST or LDDST results, ΔACTHC or Δ4C, respectively, could be used to exclude FAT.

Continuous glucose monitoring in dogs and cats.

Use of continuous glucose monitoring in veterinary medicine is gaining popularity. Through use of a commercially available continuous glucose monitor system, insights into daily glucose changes in dogs and cats are achievable. The continuous glucose monitoring system measures glucose concentrations in the interstitial fluid of the subcutaneous space by use of a small, flexible probe. When placed in the subcutaneous tissue, the probe is connected to a recording device that is attached to the animal and records the interstitial fluid glucose concentration every 5 minutes (288 readings per 24 hours). Once attached and properly calibrated, the instrument can remain in place for several days, hospitalization of the patient is not necessary, and the normal daily routine of the animal can be maintained. The data from the recording device are then downloaded and a very detailed picture of the interstitial fluid glucose concentration over that time period can be obtained. Subcutaneous interstitial fluid glucose concentrations have a good correlation to blood glucose concentrations within a defined range. The continuous glucose monitoring system has distinct advantages over traditional blood glucose curves and is a valuable tool for managing diabetic dogs and cats. In addition, other clinical uses for continuous glucose monitoring are being developed. This review is designed to outline the technology behind the continuous glucose monitoring system, describe the clinical use of the instrument, provide clinical examples in which it may be useful, and discuss future directions for continuous glucose monitoring in dogs and cats.

Endocrine and immunologic effects of inhaled fluticasone propionate in healthy dogs.

BACKGROUND: Inhaled glucocorticoids reduce airway inflammation while minimizing systemic effects in several species. HYPOTHESIS: Inhaled fluticasone suppresses the hypothalamic-pituitary-adrenal axis (HPAA), modifies immune function, and induces clinical signs to a lesser extent than PO-administered prednisone in dogs. ANIMALS: Seven healthy adult pet dogs. METHODS: Dogs were randomized to 1 of 3 treatment groups in a crossover design: fluticasone propionate (220 mug actuation of a metered dose inhaler delivered via a spacer and mask, q12h), placebo (spacer and mask alone, q12h), or prednisone (1 mg/kg PO q24h). Each treatment was administered for 3 weeks followed by a 4-week washout. Appetite, attitude, and water consumption were recorded during the last week of each treatment period. Urine cortisol : creatinine ratios, ACTH stimulation tests, white blood cell counts, lymphocyte phenotype, and serum IgM and IgA concentrations were recorded at each baseline and after the last day of each treatment. Clinical observations were expressed descriptively. Friedman's test was applied to all data comparisons. Pairwise comparisons were made with a mixed model analysis when data were normally distributed, whereas signed rank tests were used otherwise (significance P-value <.01). RESULTS: Appetite and water consumption increased during prednisone treatment. Peak serum cortisol concentrations post-ACTH were significantly decreased in prednisone- and fluticasone-treated dogs compared with placebo (prednisone > fluticasone). Serum IgM concentrations were significantly decreased in dogs treated with prednisone. CONCLUSIONS AND CLINICAL IMPORTANCE: As used, fluticasone suppresses the HPAA to a lesser extent than prednisone and may avert systemic signs associated with PO-administered glucocorticoids in dogs.

Effect of calcitriol on in vitro whole blood cytokine production in critically ill dogs.

Hypovitaminosis D has been identified as a predictor of mortality in human beings, dogs, cats and foals. However, the immunomodulatory effects of vitamin D in critically ill dogs has not been evaluated. The aim of this study was to evaluate the effect of calcitriol on cytokine production from whole blood collected from critically ill dogs in vitro. Twelve critically ill dogs admitted to a veterinary intensive care unit (ICU) were enrolled in a prospective cohort study. Whole blood from these dogs was incubated with calcitriol (2×10-7M) or ethanol (control) for 24h. Subsequent to this incubation, lipopolysaccharide (LPS)-stimulated whole blood production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were measured using a canine-specific multiplex assay. Calcitriol significantly increased LPS-stimulated whole blood production of IL-10 and decreased TNF-α production without significantly altering IL-6 production. There was no significant difference in whole blood cytokine production capacity between survivors and non-survivors at the time of discharge from the ICU or 30days after discharge. These data suggests that calcitriol induces an anti-inflammatory phenotype in vitro in whole blood from critically ill dogs.

Gallbladder Mucocele: Variables Associated with Outcome and the Utility of Ultrasonography to Identify Gallbladder Rupture in 219 Dogs (2007-2016).

BACKGROUND: Gallbladder mucocele (GBM) is an increasingly recognized extrahepatic biliary disease in dogs. OBJECTIVES: To investigate cases of GBM and identify variables associated with survival and the sensitivity and specificity of ultrasonography to identify gallbladder rupture. ANIMALS: Two hundred and nineteen client-owned dogs with GBM. METHODS: Multicenter, retrospective study of dogs with GBM, presented from January 2007 to November 2016 to 6 academic veterinary hospitals in the United States. Interrogation of hospital databases identified all cases with the inclusion criteria of a gross and histopathologic diagnosis of GBM after cholecystectomy and intraoperative bacteriologic cultures of at least 1 of the following: gallbladder wall, gallbladder contents, or abdominal effusion. RESULTS: Two hundred and nineteen dogs fulfilled the inclusion criteria. Dogs with GBM and gallbladder rupture with bile peritonitis at the time of surgery were 2.7 times more likely to die than dogs without gallbladder rupture and bile peritonitis (P = 0.001; 95% confidence interval [CI], 1.50-4.68; n = 41). No significant associations were identified between survival and positive bacteriologic cultures, antibiotic administration, or time (days) from ultrasonographic identification of GBM to the time of surgery. The sensitivity, specificity, positive, and negative likelihood ratios for ultrasonographic identification of gallbladder rupture were 56.1% (95% CI, 39.9-71.2), 91.7% (95% CI, 85.3-95.6), 6.74, and 0.44, respectively. CONCLUSION AND CLINICAL IMPORTANCE: Dogs in our study with GBM and intraoperative evidence of gallbladder rupture and bile peritonitis had a significantly higher risk of death. Additionally, abdominal ultrasonography had low sensitivity for identification of gallbladder rupture.

Desoxycorticosterone Pivalate Duration of Action and Individualized Dosing Intervals in Dogs with Primary Hypoadrenocorticism.

BACKGROUND: Clinicians alter dosing for desoxycorticosterone pivalate (DOCP) to mitigate costs, but this practice has not been critically evaluated in a prospective clinical trial. HYPOTHESIS/OBJECTIVES: The duration of action of DOCP is longer than 30 days in dogs with primary hypoadrenocorticism (PH). ANIMALS: A total of 53 client-owned dogs with PH. Twenty-four dogs with newly diagnosed PH (Group 1) and 29 dogs with treated PH (Group 2). METHODS: Prospective, multicenter, clinical trial. For phase I, DOCP was administered and plasma sodium and potassium concentrations were measured until the dog developed hyponatremia or hyperkalemia at a planned evaluation, or displayed clinical signs with plasma electrolyte concentrations outside of the reference interval independent of a planned evaluation, thus defining DOCP duration of action. Plasma electrolyte concentrations then were assessed at the end of the individualized dosing interval (IDI; i.e., DOCP duration of action minus 7 days, phase II and at least 3 months after concluding phase II, phase III). RESULTS: The duration of action of DOCP in dogs in phase I with naïve PH (n = 24) ranged from 32 to 94 days (median, 62 days; 95% confidence interval [CI], 57, 65) and previously treated PH (n = 29) from 41 to 124 days (median, 67 days; CI, 56, 72). Overall, the final DOCP dosing interval for all dogs that completed phase II (n = 36) ranged from 38 days to 90 days (median, 58 days; CI, 53, 61). No dog that completed phase III (n = 15) required reduction in the IDI. The DOCP duration of action, independent of group, was not significantly associated with several baseline variables. The median drug cost reduction using IDI was approximately 57.5% per year. CONCLUSION AND CLINICAL IMPORTANCE: The duration of action of DOCP in dogs with PH is >30 days, and plasma sodium and potassium concentrations can be maintained with an IDI >30 days long term.

Evaluation of immunomodulatory effect of recombinant human granulocyte-macrophage colony-stimulating factor on polymorphonuclear cell from dogs with cancer in vitro.

The objective of this in vitro study was to evaluate the immunomodulatory effects of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) on polymorphonuclear cell (PMN) function in dogs with cancer. PMNs were harvested from dogs with naturally developing cancer as a pre-clinical model to evaluate the immunomodulatory effects of rhGM-CSF on PMN phagocytic and cytotoxic functions, cytokine production and receptor expression. Some aspects of cancer-related PMN dysfunction in dogs with cancer were restored following incubation with rhGM-CSF including PMN phagocytosis, respiratory burst and LPS-induced TNF-α production. In addition, rhGM-CSF increased surface HLA-DR expression on the PMNs of dogs with cancer. These data suggests that dysfunction of innate immune response in dogs with cancer may be improved by rhGM-CSF. The results of this study provided a pathophysiologic rationale for the initiation of clinical trials to continue evaluating rhGM-CSF as an immunomodulatory therapy in dogs with cancer.

Plasma inflammatory mediator concentrations at ICU admission in dogs with naturally developing sepsis.

BACKGROUND: Identifying biomarkers to aide in the diagnosis and prognostication of sepsis in dogs would be valuable to veterinarians. OBJECTIVE: To compare plasma inflammatory mediator concentrations among dogs with sepsis, noninfectious systemic inflammatory response syndrome (NSIRS), and healthy dogs. ANIMALS: Dogs with sepsis (n = 22), NSIRS (n = 23), and healthy dogs (n = 13) presenting to the intensive care unit (ICU) at a veterinary teaching hospital. METHODS: Prospective observational study. Clinical parameters were recorded for each dog and plasma tumor necrosis factor (TNF) bioactivity and concentrations of interleukin (IL)-6, CXC chemokine ligand (CXCL)-8 and IL-10 were determined at ICU presentation. RESULTS: Dogs with sepsis and NSIRS were significantly more likely to have measurable TNF activity (sepsis 20/22; NSIRS 19/20; healthy 0/13) and IL-6 concentration (sepsis 12/22; NSIRS 15/23; healthy 2/13), than healthy dogs. Healthy dogs (9/13) were significantly more likely to have measurable plasma IL-10 concentrations than dogs with sepsis (4/19), but not NSIRS (7/20). None of the inflammatory mediators evaluated had optimal sensitivity or specificity for the diagnosis of sepsis. Twelve of 22 dogs with sepsis and 15/23 dogs with NSIRS survived to discharge; none of the measured biomarkers correlated with survival to discharge. CONCLUSIONS AND CLINICAL IMPORTANCE: Sepsis and NSIRS are associated with increased production of the proinflammatory cytokines TNF and IL-6. In addition, sepsis is associated with decreased production of the anti-inflammatory cytokine IL-10. Despite this, plasma TNF, IL-6, CXCL-8, and IL-10 measured at ICU presentation do not appear to be valuable biomarkers to differentiate sepsis from NSIRS, or predict hospital outcome.

Pathogen associated molecular pattern motifs from Gram-positive and Gram-negative bacteria induce different inflammatory mediator profiles in equine blood.

Although the incidence of Gram-positive infection in horses is increasing, little is known about differences in inflammatory response between Gram-positive and Gram-negative organisms in this species. Equine blood was stimulated with components of both Gram-negative and Gram-positive organisms: lipopolysaccharide (LPS); lipoteichoic acid (LTA); peptidoglycan (PG); with combinations of LPS, LTA and PG; and with phosphate buffered saline (control). LPS, LTA and PG stimulated tumor necrosis factor (TNF) and interleukin (IL)-6 production but only LTA and PG stimulated IL-1ß production from whole blood. LPS was a more potent inducer of TNF than either LTA or PG and both LPS and LTA were more potent inducers of IL-6 than PG. Generally, combinations of pathogen associated molecular patterns (PAMPs) did not elicit greater inflammatory mediator responses when compared to LPS, LTA or PG alone, although there was some synergism between the effects of LPS and LTA. The repertoire of inflammatory mediators provoked by Gram-positive vs. Gram-negative motifs is thus distinctly different. As novel immunomodulatory therapies are developed for use in the horse, care should be exercised when applying treatments for endotoxemia to animals with Gram-positive infections given the different cytokine response profiles.

Effect of opioids on CXCL-8 production in healthy cats.

The aim of this study was to evaluate the effect of opioid exposure on CXC chemokine ligand (CXCL)-8 production in cats using whole blood culture. Morphine, buprenorphine, fentanyl, and saline control were administered intravenously to five cats and whole blood pathogen associated molecular pattern motif-induced CXCL-8 production capacity was evaluated. Morphine potentiated CXCL-8 production. To further characterize this effect of morphine, morphine was incubated with whole blood ex vivo and pathogen associated molecular pattern motif-induced CXCL-8 production capacity was measured. There was a time and concentration dependent effect on CXCL-8 production, suggesting the proinflammatory effect of morphine is at least partially mediated by direct stimulatory effects on leukocytes. Additional investigation is indicated to assess the implications of the immunomodulatory actions of opioids in cats.

Evaluation of serum NT-pCNP as a diagnostic and prognostic biomarker for sepsis in dogs.

BACKGROUND: There is a need for diagnostic biomarkers that can rapidly differentiate dogs with sepsis from dogs with noninfectious forms of systemic inflammatory response syndrome (NSIRS). OBJECTIVES: To compare serum NT-pCNP concentrations among dogs with various forms of sepsis, NSIRS, and healthy controls and to evaluate the use of serum NT-pCNP for the diagnosis of various forms of sepsis in dogs. ANIMALS: One hundred and twelve dogs including 63 critically ill dogs (sepsis n = 29; NSIRS n = 34) and 49 healthy control dogs. METHODS: Prospective clinical investigation. Serum samples were collected for NT-pCNP measurement from dogs with sepsis or NSIRS within 24 hours of intensive care unit admission or at the time of presentation for healthy dogs. Dogs with sepsis were subclassified based on the anatomic region of infection. Serum NT-pCNP concentrations were compared among sepsis, NSIRS and healthy groups as well as among sepsis subgroups. The area under the curve (AUC), sensitivity, and specificity for identifying dogs with sepsis were determined. RESULTS: Using a cut-off value of 10.1 pmol/L, AUC, sensitivity, and specificity of NT-pCNP for differentiating dogs with sepsis from dogs with NSIRS or healthy control dogs were 0.71 (95% CI, 0.58-0.85), 65.5% (45.7-82.1%), and 89.2% (80.4-94.9%), respectively. Serum NT-pCNP had poor sensitivity for peritoneal sources of sepsis; AUC [0.92 (0.81-1.0)], sensitivity [94% (71-100%)], and specificity [89% (80-95%)] improved when these dogs were excluded. Serum NT-pCNP concentration was not associated with survival in the sepsis group. CONCLUSIONS AND CLINICAL IMPORTANCE: Serum NT-pCNP is a promising diagnostic biomarker for sepsis but is a poor indicator of septic peritonitis.

Plasma nitrate/nitrite concentrations in dogs with naturally developing sepsis and non-infectious forms of the systemic inflammatory response syndrome.

The aim of this prospective observational study was to evaluate the differences in plasma nitrate/nitrite concentrations between dogs with sepsis and those with non-infectious forms of the systemic inflammatory response syndrome (SIRS). Eighteen dogs with sepsis, 20 dogs with SIRS and 29 healthy control dogs were enrolled. Blood samples were obtained from the dogs within 12 hours of admission to the University of Missouri Veterinary Medical Teaching Hospital (MU VMTH) Intensive Care Unit (ICU) in lithium heparin blood tubes. Plasma nitrate/nitrite concentrations were measured using the Greiss reaction. Plasma nitrate/nitrite concentrations at presentation, clinical parameters, organ dysfunction and in-hospital mortality were compared between groups. Plasma total nitrate/nitrite was significantly greater in the sepsis group compared with the control group (P=0.005) and SIRS group (P=0.037). There was no statistical difference in plasma nitrate/nitrite concentration between the SIRS and control groups (P=0.489). The sensitivity was 66.7 per cent (95 per cent CI, 41 to 87 per cent) and the specificity was 75.5 per cent (95 per cent CI, 61 to 87 per cent) for differentiating dogs with sepsis from dogs without sepsis.