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Objective: To evaluate the stability of canine and feline hemostatic proteins in freeze-thaw-cycled (FTC) fresh frozen plasma (FFP)., Design: Prospective study., Setting: Veterinary Teaching Hospital., Animals: Nine blood donor dogs and 10 blood donor cats., Interventions: Whole blood was collected and separated into packed RBC and plasma units according to standard methods. Each unit of plasma was divided into 2 equal aliquots and frozen (-41 °C). One aliquot from each donor (FTC) was then thawed and then refrozen (-41 °C) until time of analysis. The second aliquot (nonfreeze-thaw-cycled; NFTC) remained frozen until time of analysis. The hemostatic proteins assessed included coagulation factors, anticoagulant factors (antithrombin and Protein C), and adhesive proteins (fibrinogen and von Willebrand Factor). The coagulant activities of factors II, VII, VIII, IX, X, XI, and XII were measured in modified one-stage activated partial thromboplastin time or prothrombin time assays. Antithrombin and Protein C activities were measured in chromogenic substrate assays. Clottable fibrinogen was measured via the Clauss method, and von Willebrand Factor concentration (vWF:Ag) was measured in an ELISA. A paired t-test was utilized to identify differences in factor activity or concentration between FTC FFP and NFTC FFP., Measurements and Main Results: No clinically or statistically significant differences (all P>0.05) were identified between FTC FFP and NFTC FFP., Conclusions: Refreezing FFP within 1 hour of initial thawing appeared to have no deleterious effects on the hemostatic protein activity or content of that unit. Transfusion of FTC FFP is expected to provide the recipient with comparable replacement of hemostatic proteins as FFP that has remained frozen., (© Veterinary Emergency and Critical Care Society 2010.)

Objective: To describe the computed tomographic and magnetic resonance imaging features of segmental caudal vena cava aplasia and associated vascular anomalies in dogs., Methods: A retrospective study was performed reviewing computed tomographic and magnetic resonance imaging archives of eight institutions for dogs with segmental caudal vena cava aplasia. Inclusion criteria included a computed tomographic or magnetic resonance imaging study and supportive diagnostic and follow-up information. Abdominal vessels were reviewed for size, shape, location and course (including tributaries and branches) and classified as normal, abnormal or shunt vessels., Results: Ten dogs with segmental caudal vena cava aplasia were identified. In all dogs, postrenal caval blood was shunted to either a right or a left azygos vein, with seven different angiographic patterns. Affected dogs were predominantly female (70 per cent) and young (mean 2.6 years). Additional portocaval and porto-azygos shunt vessels were identified in two cases each. Computed tomographic angiography and magnetic resonance angiography depicted details of abdominal vessels including thrombus formation in one dog., Clinical Significance: Segmental caudal vena cava aplasia is a vascular congenital anomaly in the dog that can be associated with thrombosis and portosystemic shunts. Computed tomographic angiography and magnetic resonance angiography are excellent tools to demonstrate the complex vascular anatomy and to guide treatment planning for portosystemic shunts and thrombolytic therapy.

Vascular endothelial growth factor (VEGF) has potent angiogenic, mitogenic, and vascular permeability enhancing properties specific for endothelial cells. VEGF is present in high concentrations in inflammatory and neoplastic body cavity effusions and has been implicated in the pathogenesis of neoplastic and inflammatory effusion formation. In this study, VEGF was quantitated by solid-phase enzyme-linked immunoadsorbent assay (ELISA) in samples of pericardial, pleural, and peritoneal effusions (N = 38) from dogs (N = 35) with neoplastic and non-neoplastic diseases. VEGF was detected in 37 of 38 effusions (median, 754; range, 18-3,669 pg/mL) and was present in much higher concentrations than in previously established normal concentrations for canine plasma (median, < 1 pg/mL; range, < 1-18 pg/mL) or in those previously noted in the plasma of dogs with hemangiosarcoma (HSA; median, 17 pg/mL; range, < 1-67 pg/mL). In 4 dogs with HSA, the concurrent plasma VEGF concentration was much lower than in the abdominal effusion (P = .029). No significant correlation was demonstrated between VEGF effusion concentration and effusion total protein content or nucleated cell count. Mean VEGF concentrations were significantly higher in pericardial (median, 3,533; range, 709-3,669 pg/mL) and pleural effusions (median, 3,144; range, 0-3,663 pg/mL) compared to peritoneal effusions (median, 288; range, 18-2,607 pg/mL; P < .05). There was no marked difference demonstrated between effusions associated with malignant and nonmalignant diseases. Further studies are necessary to elucidate the role of VEGF in body cavity effusion formation in dogs.

Vascular endothelial growth factor (VEGF) is a dimeric glycosylated polypeptide growth factor with potent angiogenic, mitogenic, and vascular permeability-enhancing properties specific for endothelial cells. In humans, VEGF seems to play a major role in tumor growth, and plasma concentrations correlate with tumor burden, response to therapy, and disease progression. This study compared plasma VEGF concentrations in healthy client-owned dogs (n = 17) to dogs with hemangiosarcoma (HSA; n 16). Dogs with HSA were significantly more likely to have detectable concentrations of plasma VEGF (13/17) compared to healthy dogs (1/17; P < .001). The median plasma VEGF concentration for dogs with HSA was 17.2 pg/mL (range, < 1.0-66.7 pg/mL). Plasma VEGF concentrations in dogs with HSA did not correlate with stage of disease or tumor burden, but 1 dog had undetectable VEGF during chemotherapy that subsequently increased with disease progression.

Establishing and maintaining vascular access is often vital to the preoperative, intraoperative, and postoperative management of the small animal emergency surgical patient. Vascular access may be used for the delivery of crystalloids, colloids, blood components, medications, and anesthetic or sedative agents. It can also facilitate venous and arterial blood sampling and allow direct measurement of arterial and venous pressures. The small animal emergency and critical care veterinarian should have a thorough knowledge of vascular access techniques, including peripheral and central venous catheterization, intraosseous, and arterial access. Competence in percutaneous, percutaneous facilitative, and surgical cutdown approaches should ensure that vascular access can always be established in the critically ill patient.