Progression of lipase activity and pancreatic lipase immunoreactivity in dogs hospitalized for acute pancreatitis and correlation with clinical features.

BACKGROUND: Lipase activity and pancreatic lipase immunoreactivity (PLI) have not been compared in dogs hospitalized for acute pancreatitis (AP). OBJECTIVES: To describe the progression of lipase activity and PLI, and correlations with clinicopathologic features in dogs with AP. ANIMALS: Thirty-nine dogs with AP based on clinical signs and lipase activity >350 U/L (reference interval [RI], 24-108 U/L). METHODS: Retrospective study. Lipase activity (LIPC Roche), PLI (SpecPL), and clinical signs were recorded daily. Admission (d1) data (clinical, laboratory, and ultrasound [US] findings), and clinical signs during hospitalization (d2-d3) were assessed for correlation with lipases. RESULTS: Median (range) duration of clinical signs before presentation was 2 days (1-7 days). Median (range) lipase activity and PLI at d1 were 1070 U/L (range, 357-1500 U/L) and 1111 µg/L (range, 292-1500 µg/L). Strong correlation between assays at d1 (rs 0.96; P < .0001; n = 39), remained equally strong on d2 (rs 0.964; P < .0001; n = 39), and d3 (rs 0.966; P < .0001; n = 22). On d2, lipase activity and PLI were within RI in 13/39 (33%) and 18/39 (46%) of cases. Lipase activities were minimally increased (median, 124 U/L) in 5 dogs with d2 PLI <200 µg/L. On d3, 4 more dogs had normal lipase activity and PLI, and the nature and magnitude of change were always the same for both assays. Clinical signs were not associated with lipases. Only a hyperechoic mesentery, but not an US diagnosis of AP, correlated significantly with lipase activity and PLI. CONCLUSIONS AND CLINICAL IMPORTANCE: Lipase decreases rapidly to near or within RI within 2 days of treatment in the majority of dogs with AP. Both lipase assays yielded virtually identical results. Mesenteric echogenicity may be an early marker of AP in dogs.

Coagulation Status in Dogs Naturally Infected with Angiostrongylus vasorum.

Angiostrongylus vasorum infection has been associated with coagulopathies including hyperfibrinolysis. We compared coagulation status including thromboelastometry (ROTEM) parameters in dogs naturally infected with A. vasorum versus healthy dogs to determine clinicopathological parameters associated with bleeding, hypocoagulopathy, and hyperfibrinolysis. Clinical signs, white blood cell count, platelet count, hematocrit, plasmatic coagulation tests (PT, aPTT, fibrinogen concentration), D-dimer, and ROTEM S parameters (Ex-tem, In-tem, Fib-tem, Ap-tem) were analysed and compared between bleeding, nonbleeding, and control dogs and between hypo- and normocoagulable animals. Clinical signs of bleeding were present in 6/9 (67%) hypocoagulable and 1/9 (11%) normocoagulable dogs. PT, fibrinogen concentration, and several ROTEM parameters were significantly different between hypocoagulable and normocoagulabe A. vasorum infected dogs. Hyperfibrinolysis was identified in 44% of infected dogs and was significantly more common in bleeding and hypocoagulable dogs. Hyperfibrinolysis was significantly associated with low MCFFib-tem but not with low fibrinogen concentration or increased D-dimers. CFTEx-tem > 248 swas 100% sensitive and 89% specific to predict hyperfibrinolysis. Hyperfibrinolysis, hypocoagulability and bleeding are common in A. vasorum infected dogs. Only Ex-tem and Fib-tem parameters and potentially PT were associated with bleeding or hypocoagulability. Ex-tem analysis enables detection of bleeding, hypocoagulability and hyperfibrinolysis within minutes.

Triggers, risk factors and clinico-pathological features of urticaria in dogs - a prospective observational study of 24 cases.

BACKGROUND: Urticaria and anaphylaxis are frequently encountered in veterinary practice, but little is known about the causes and relative frequencies of these reactions. HYPOTHESIS/OBJECTIVES: This study was designed to improve current knowledge on the triggers, risk factors and clinico-pathological features of urticaria. ANIMALS: Twenty four dogs with signs of urticaria with or without anaphylaxis. METHODS: The study included dogs with cutaneous immediate-type hypersensitivity reactions. The cases were grouped by clinical severity into either an urticaria or an anaphylaxis group. All treatments and diagnostic tests (haematology, biochemical profile, allergy investigation) were recorded. A causality algorithm for urticaria and anaphylaxis (ALUA) was designed to determine the probability of the identified triggers and cofactors. Disease incidence, breed, age and gender predispositions were evaluated statistically. RESULTS: Sixteen of 24 urticaria cases were associated with anaphylaxis whilst 8 of 24 were confined to the skin. The annual hospital incidence was 0.12%. Females seemed to be over-represented (2.4:1) and most of the dog breeds were pure breed (22 of 24), with Rhodesian ridgeback, boxer, beagle, Jack Russell terrier, French bulldog and Vizslas over-represented. In addition to skin lesions, the most frequently and severely affected organ systems were the gastrointestinal and cardiovascular systems. The predominant blood abnormalities were elevated lipase and alanine aminotransferase values. Insects, food and drugs were the most commonly identified triggers. CONCLUSIONS: To the best of our knowledge, this is the first study describing the trigger factors and clinico-pathological features of dogs with urticaria in veterinary medicine. Insects, food and drugs were the most frequently detected triggers.

Effect of hypothyroidism on insulin sensitivity and glucose tolerance in dogs.

OBJECTIVE: To determine the effects of hypothyroidism on insulin sensitivity, glucose tolerance, and concentrations of hormones counter-regulatory to insulin in dogs. ANIMALS: 8 anestrous mixed-breed bitches with experimentally induced hypothyroidism and 8 euthyroid control dogs. PROCEDURES: The insulin-modified frequently sampled IV glucose tolerance test and minimal model analysis were used to determine basal plasma insulin and glucose concentrations, acute insulin response to glucose, insulin sensitivity, glucose effectiveness, and disposition index. Growth hormone response was assessed by stimulation and suppression tests. Additionally, basal serum growth hormone (GH) and insulin-like growth factor-1 (IGF-1) concentrations and urine cortisol-to-creatinine concentration ratios were measured and dual energy x-ray absorptiometry was performed to evaluate body composition. RESULTS: Insulin sensitivity was lower in the hypothyroid group than in the euthyroid group, whereas acute insulin response to glucose was higher. Glucose effectiveness and disposition index were not different between groups. Basal serum GH and IGF-1 concentrations as well as abdominal fat content were high in hypothyroid dogs, but urine cortisol-to-creatinine concentration ratios were unchanged. CONCLUSIONS AND CLINICAL RELEVANCE: Hypothyroidism appeared to negatively affect glucose homeostasis by inducing insulin resistance, but overall glucose tolerance was maintained by increased insulin secretion in hypothyroid dogs. Possible factors affecting insulin sensitivity are high serum GH and IGF-1 concentrations and an increase in abdominal fat. In dogs with diseases involving impaired insulin secretion such as diabetes mellitus, concurrent hypothyroidism can have important clinical implications.

Simultaneous application of the vascular endothelial growth factor (VEGF) receptor inhibitor PTK787/ZK 222584 and ionizing radiation does not further reduce the growth of canine oral melanoma xenografts in nude mice.

PTK787/ZK 222584 is an inhibitor of the vascular endothelial growth factor (VEGF) receptor tyrosine kinases. In this study, the effectiveness of PTK787/ZK 222584 and radiation on canine oral melanoma xenografts was assessed. Xenografts were treated with radiotherapy (4x6Gy), or with PTK787/ZK 222584, or with a combination of both. Treatment efficacy was assessed using a tumour growth delay assay, serial power Doppler and pO(2) measurements during and after therapy. There was a significant growth delay for the group treated with radiation alone and for the combined treatment group. However, tumour growth delay was similar in both groups. Tumours were hypoxic before irradiation and no significant re-oxygenation occurred during therapy. In all tumours, vascularity and perfusion were significantly lower at the end of the study but no significant differences in perfusion, vascularity and oxygenation status were observed between and within treatment groups. The combination of PTK787/ZK 222584 and radiotherapy did not perform better than radiotherapy alone in this model.

Preliminary study of plasma vascular endothelial growth factor (VEGF) during low- and high-dose radiation therapy of dogs with spontaneous tumors.

High plasma vascular endothelial growth factor (VEGF) concentrations are associated with radiation resistance and poor prognosis. After an exposure to ionizing radiation in cell culture an early phase and a late phase of increased VEGF have been documented. The activation was dependent on the radiation dose. Therefore, the purpose of this study was to measure baseline plasma VEGF and changes in VEGF over the course of fractionated radiation therapy in dogs with spontaneous tumors. Dogs with tumors had a significantly higher pretreatment plasma VEGF than did dogs without tumors. Immediately after irradiation no increased plasma VEGF was observed. Over the course of radiation therapy there was an increased plasma VEGF in dogs treated with low doses per fraction/high total dose, whereas plasma VEGF remained stable in dogs irradiated with high doses per fraction/low total dose. The regulatory mechanisms are very complex, and therefore the value of plasma VEGF measurements as an indirect marker of angiogenesis induced by radiotherapy is limited.

Oxygenation of spontaneous canine tumors during fractionated radiation therapy.

BACKGROUND AND PURPOSE: Tumor oxygenation predicts treatment outcome, and reoxygenation is considered important in the efficacy of fractionated radiation therapy. Therefore, the purpose of this study was to document the changes of the oxygenation status in spontaneous canine tumors during fractionated radiation therapy using polarographic needle electrodes. MATERIAL AND METHODS: Tumor oxygen partial pressure (pO(2)) measurements were performed with the Eppendorf-pO(2)-Histograph. The measurements were done under general anesthesia, and probe tracks were guided with ultrasound. pO(2) was measured before radiation therapy in all dogs. In patients treated with curative intent, measurements were done sequentially up to eight times (total dose: 45-59.5 Gy). Oxygenation status of the palliative patient group was examined before each fraction of radiation therapy up to five times (total dose: 24-30 Gy). RESULTS: 15/26 tumors had a pretreatment median pO(2) < or = 10 mmHg. The pO(2) values appeared to be quite variable in individual tumors during fractionated radiation therapy. The pO(2) of initially hypoxic tumors (pretreatment median pO(2) < or = 10 mmHg) remained unchanged during fractionated radiotherapy, whereas in initially normoxic tumors the pO(2) decreased. CONCLUSION: Hypoxia is common in spontaneous canine tumors, as 57.7% of the recorded values were < or = 10 mmHg. The data of this study showed that initially hypoxic tumors remained hypoxic, whereas normoxic tumors became more hypoxic.