Effect of ascorbic acid on storage of Greyhound erythrocytes.

OBJECTIVE: To assess changes in biochemical and biophysical properties of canine RBCs during cold (1° to 6°C) storage in a licensed RBC additive solution (the RBC preservation solution designated AS-1) supplemented with ascorbic acid. SAMPLE: Blood samples from 7 neutered male Greyhounds; all dogs had negative results when tested for dog erythrocyte antigen 1.1. PROCEDURES: Blood was collected into citrate-phosphate-dextrose and stored in AS-1. Stored RBCs were supplemented with 7.1mM ascorbic acid or with saline (0.9% NaCl) solution (control samples). Several biochemical and biophysical properties of RBCs were measured, including percentage hemolysis, oxygen-hemoglobin equilibrium, and the kinetic rate constants for O2 dissociation, carbon monoxide association, and nitric oxide dioxygenation. RESULTS: Greyhound RBCs stored in AS-1 supplemented with ascorbic acid did not have significantly decreased hemolysis, compared with results for the control samples, during the storage period. CONCLUSIONS AND CLINICAL RELEVANCE: In this study, ascorbic acid did not reduce hemolysis during storage. Several changes in stored canine RBCs were identified as part of the hypothermic storage lesion.

Plasma N-terminal pro-B-type natriuretic peptide concentration in healthy retired racing Greyhounds.

BACKGROUND: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a cardiac biomarker whose plasma concentration is high in some dogs with cardiopulmonary disease. NT-proBNP is a diagnostic tool that can be used to help determine if a patient has congestive heart failure. Greyhounds have functional heart murmurs, relative cardiomegaly, and high serum cTnI concentration. OBJECTIVES: The purpose of the study was to evaluate the plasma concentration of NT-proBNP in healthy Greyhounds and compare it to non-Greyhound dogs. METHODS: We prospectively evaluated healthy client-owned dogs including retired racing Greyhounds and non-Greyhounds. Plasma was obtained and transferred into tubes containing a protease inhibitor and submitted for a specific NT-proBNP ELISA assay. RESULTS: The plasma NT-proBNP concentration in Greyhounds was significantly higher than in non-Greyhound control dogs (946 vs 632 pmol/L; P < .005); 46% of Greyhounds had NT-proBNP > 1000 pmol/L. CONCLUSIONS: Plasma NT-proBNP concentration in Greyhounds is high and should be interpreted with caution.

Evaluation of hemostatic activity of canine frozen plasma for transfusion by thromboelastography.

BACKGROUND: In humans, fresh frozen plasma (FFP) loses factor V and VIII activities after 1 year. It then becomes frozen plasma (FP), and theoretically is unsuitable for use in patients with coagulopathies. These findings have not been reported for dogs. HYPOTHESIS: Canine FP is hemostatically active after 5 years of storage. ANIMALS: Fresh plasma (Group FsP; n = 15) and 5-year-old FP (Group FzP; n = 10) from blood bank donors. METHODS: Group FsP and Group FzP samples were evaluated by thromboelastography (TEG), one-stage prothrombin time (OSPT), activated partial thromboplastin time (APTT), fibrinogen, and antithrombin. Fresh plasma (n = 6) and a subset of Group FzP (n = 8) were evaluated for clotting factor activities (V, VIII, IX, X). A 2nd experiment using short-term storage of thawed FP under suboptimal conditions (refrigerated [4°C] or refrozen [-20°C]) by TEG was performed to simulate general practice storage capabilities. RESULTS: Group FzP had shorter reaction time (P = .0007) and larger angle (P = .0004) compared with Group FsP by TEG, suggesting hypercoaguability. Factor VIII and X activities were lower in Group FzP (P = .02 and .005, respectively). Fibrinogen, OSPT, and APTT were significantly lower or longer for Group FzP than Group FsP (P < .05), but most values remained within reference intervals for dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: Five-year-old canine FP stored at -30°C is hemostatically active and should be clinically evaluated in patients with coagulopathies. If active, the monetary savings of using older plasma will be substantial.

Effect of sevoflurane anesthesia and blood donation on the sonographic appearance of the spleen in 60 healthy cats.

The aims of this prospective study were to describe the normal sonographic size and appearance of the feline spleen, and to test effects of sevoflurane anesthesia and blood collection on sonographic characteristics. Sonographic evaluations were performed in 60 healthy blood donor cats prior to anesthesia and blood collection (baseline), after anesthesia induction, after completion of blood collection while under anesthesia, and 7-10 days after blood collection. Transverse sonographic images of the splenic mid-body were made. Splenic height, width, cross-sectional area, echogenicity relative to the left renal cortex, and echotexture were recorded. Height, width, and cross-sectional area were compared across time periods using linear-mixed effects models. Holm's method was applied to adjust for multiplicity and control the overall Type 1 error rate at α = 0.05. Normal transverse sonographic splenic measurements (mean ± standard deviation) at baseline were: height 8.2 ± 1.4 mm; width 26.7 ± 4.4 mm; and CSA 1.6 ± 0.5 cm(2) . While there were statistically significant differences in splenic height, width, and cross-sectional area after sevoflurane anesthesia and/or blood collection, differences were of low magnitude. The spleen was diffusely homogenous and subjectively isoechoic or mildly hyperechoic relative to the left renal cortex. In 77% of castrated male cats, the spleen was isoechoic to the left renal cortex. We conclude that sevoflurane anesthesia and blood donation do not subjectively alter splenic dimensions, echogenicity and echotexture in normal cats.

Epsilon aminocaproic acid for the prevention of delayed postoperative bleeding in retired racing greyhounds undergoing gonadectomy.

OBJECTIVE: To evaluate the effects of epsilon aminocaproic acid (EACA) on the prevalence of postoperative bleeding in retired racing Greyhounds (RRG), and to assess its effects on selected thrombelastography (TEG) and fibrinolysis variables. STUDY DESIGN: Double-blinded, prospective, randomized study. METHODS: 100 RRG had elective ovariohysterectomy or orchiectomy and were administered EACA or placebo for 3 days after surgery. TEG variables were analyzed preoperatively and 24, 48, and 72 hours after surgery. RESULTS: Thirty percent (15/50) of RRG in the placebo group had delayed postoperative bleeding starting 36-48 hours after surgery compared with 10% (5/50) in the EACA group (P = .012). On the TEG variables, the slopes for R and K time were significantly different between treatment groups (P <.05); the R and K time decreased over time in the EACA group after surgery whereas they increased in the placebo group. The angle, maximal amplitude (MA), and G slopes were also significantly different between treatment groups (P = .001, .001, and .006, respectively). The angle, MA, and G increased postoperatively over time in the EACA group and decreased in the placebo group. All these changes are supportive of hypercoagulability associated with EACA administration. CONCLUSION: Postoperative administration of EACA significantly decreased the prevalence of postoperative bleeding in RRG undergoing surgery by increasing the clot strength.

Retrospective evaluation of the effectiveness of epsilon aminocaproic acid for the prevention of postamputation bleeding in retired racing Greyhounds with appendicular bone tumors: 46 cases (2003-2008).

OBJECTIVES: To determine the frequency of delayed postoperative bleeding in retired racing Greyhounds with appendicular bone tumors undergoing limb amputations. To identify if administration of epsilon-aminocaproic acid (EACA) was effective on the prevention of postoperative bleeding. DESIGN: Retrospective study from December 2003 to December 2008. SETTING: Veterinary university teaching hospital. ANIMALS: Forty-six retired racing Greyhounds (RRGs) diagnosed with primary appendicular bone tumors that underwent limb amputation were included in the study. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Thirteen of 46 RRGs (28%) included in the study had delayed postoperative bleeding starting 48-72 h after surgery. Bleeding episodes included cutaneous, subcutaneous, and external bleeding that extended from the area of the surgical site that became widespread within hours, and that required administration of blood components. A paired t-test suggests that there was a significant decrease in PCV postoperatively for both dogs that bled and dogs that did not bleed (P < 0.0001). Forty of 46 RRGs (86%) received either fresh frozen plasma (FFP) or EACA or both, for the prevention of postoperative bleeding. A logistic regression model determined that dogs that did not receive EACA were 5.7 times more likely to bleed than dogs that did receive EACA, when controlling for whether or not they received FFP (95% CI: 1.02-32.15, P = 0.047). CONCLUSION: This retrospective study suggests that preemptive postoperative administration of EACA appears to be efficacious in decreasing the frequency of bleeding in RRGs undergoing limb amputation; however, a prospective study is warranted to corroborate its effectiveness.

Serum concentrations of IgG, IgA, and IgM in retired racing Greyhound dogs.

BACKGROUND: Greyhound dogs have significant physiologic, hematologic, and biochemical differences when compared with other breeds, including significantly lower serum globulin concentration owing to decreases in the α- and ß-globulin fractions. The specific proteins that account for differences in globulin concentrations are not known, but IgA and IgM, both ß-globulins, are potential candidates. OBJECTIVES: The aims of this study were to measure serum IgG, IgA, and IgM in clinically healthy retired racing Greyhounds and compare the results with those of age- and sex-matched non-Greyhound dogs. METHODS: Study animals included 25 Greyhound and 20 non-Greyhound dogs. Total protein, albumin, and total globulin concentrations were determined. IgG, IgA, and IgM concentrations were measured using a commercially available radial immunodiffusion kit. The Student t-test assuming equal variances was used to compare concentrations of immunoglobulins between groups. RESULTS: Serum concentrations of IgA and IgM in Greyhounds (IgA=49±20 mg/dL; IgM=132±47 mg/dL) were significantly lower than concentrations in non-Greyound dogs (IgA=70±39 mg/dL; Ig M=212±78 mg/dL). Concentrations of IgG did not differ between groups. CONCLUSIONS: Mean serum IgA and IgM concentrations in Greyhounds were lower than those in non-Greyhound dogs. This may contribute to low serum concentrations of ß-globulins in Greyhounds. Specific reference intervals are recommended for Greyhounds to avoid possible misdiagnosis of IgA or IgM deficiency.

Acute phase protein concentrations in retired racing Greyhounds.

BACKGROUND: Retired racing Greyhounds are popular as pets. Greyhounds have several differences in physiological values compared with other breeds, including lower serum alpha- and beta-globulin concentrations. We hypothesized that lower acute phase protein (APP) concentrations could contribute to lower alpha- and beta-globulin concentrations in this breed. OBJECTIVES: The purpose of this study was to compare serum concentrations of several APPs in Greyhounds with those of other dog breeds. METHODS: We measured the serum concentrations of C-reactive protein (CRP), haptoglobin (Hp), acid-soluble glycoprotein (ASG), ceruloplasmin (CP), and serum amyloid A (SAA) in 15 clinically healthy retired racing Greyhounds and 11 age- and gender-matched healthy nonGreyhound controls using previously validated methods. Results were compared by Student's t-tests. RESULTS: The concentration of Hp by both colorimetric and immunoturbidimetric methods was significantly lower in Greyhounds than in nonGreyhound dogs (P=.0009 and .019, respectively). The concentration of ASG was also significantly (P=.007) lower in Greyhounds, but CRP and CP concentrations were not significantly different between groups. SAA concentration was below the detection limit of the method in all dogs. CONCLUSIONS: The low serum concentrations of Hp and ASG should be taken into consideration when interpreting APP results in Greyhounds. Because both Hp and some ASG migrate in the alpha-globulin fraction, these results may explain the low alpha-globulin concentrations in Greyhounds.

Effects of blood collection for transfusion on arterial blood pressure, heart rate, and PCV in cats.

BACKGROUND: Collection of 50 mL of blood (standard unit) in cats is a common procedure. There are several studies on the health status of donors, but to our knowledge there are no reports on the effects of blood collection on the feline donor. HYPOTHESIS: Collection of a standard unit of blood from cats does not significantly change arterial blood pressure (BP), mean arterial pressure (MAP), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), PCV, and heart rate (HR) in healthy blood donor cats. ANIMALS: Twenty-six healthy blood donor cats (6 spayed females and 20 castrated males). METHODS: An oscillometric method was used to measure MAP, SAP, DAP, and to quantify HR before and after blood collection; PCV was obtained before and immediately after blood collection. RESULTS: Despite a significant decrease (P < .05) in all variables (ie, BP, PCV, HR) after blood collection, no adverse events were observed. CONCLUSIONS AND CLINICAL IMPORTANCE: The collection of a unit of blood for transfusion from healthy donor cats weighing more than 5 kg appears to be safe, but this procedure leads to a decrease in arterial BP, PCV, and HR.