Artifactual changes in canine blood following storage, detected using the ADVIA 120 hematology analyzer

BACKGROUND: Artifactual changes in blood may occur as a consequence of delayed analysis and may complicate interpretation of CBC data. OBJECTIVE: The aim of this study was to characterize artifactual changes in canine blood, due to storage, using the ADVIA 120 hematology analyzer. METHODS: Blood samples were collected into EDTA from 5 clinically healthy dogs. Within 1 hour after blood sample collection and at 12, 24, 36 and 48 hours after storage of the samples at either 4 degrees C or room temperature (approximately 24 degrees C), a CBC was done using the ADVIA 120 and multispecies software. A linear mixed model was used to statistically evaluate significant differences in values over time, compared with initial values. RESULTS: The HCT and MCV were increased significantly after 12 hours of collection at both 4 degrees C and 24 degrees C, and continued to increase through 48 hours. The MCHC initially decreased significantly at 12-24 hours and then continued to decrease through 48 hours at both temperatures. Changes in HCT, MCV, and MCHC were greater at 24 degrees C than at 4 degrees C at all time points. A significant increase in MPV and a decrease in mean platelet component concentration were observed at all time points at 24 degrees C. Samples stored at 24 degrees C for 48 hours had significantly higher percentages of normocytic-hypochromic RBCs, and macrocytic-normochromic RBCs, and lower platelet and total WBC counts. CONCLUSIONS: Delayed analysis of canine blood samples produces artifactual changes in CBC results, mainly in RBC morphology and platelet parameters, that are readily detected using the ADVIA 120. Refrigeration of specimens, even after 24 hours of storage at room temperature, is recommended to improve the accuracy of CBC results for canine blood samples.     

Effects of blood processing techniques on sodium and potassium values: a comparison between Aldabra tortoises (Geochelone gigantea) and Burmese mountain tortoises (Manouria emys)

Background: Hematologic and plasma biochemical evaluations are routinely used in evaluating the chelonian patient, but appropriate processing techniques have been minimally defined.
Objectives: This study was designed to compare the effects of temperature, time, anticoagulant, and species on sodium and potassium values in the Aldabra tortoise ( Geochelone gigantea ) and the Burmese mountain tortoise ( Manouria emys ).
Methods: Blood samples from 7 Aldabra tortoises and 8 Burmese mountain tortoises were collected into tubes without anticoagulant and tubes containing lithium heparin. Sodium and potassium concentrations were measured by flame photometry in serum and plasma harvested immediately after collection and from aliquots of whole blood stored at 4°C and 25°C for 5 to 120 minutes.
Results: In Aldabra tortoises, storage time and temperature had no significant effect on potassium concentrations in heparinized blood and in blood without anticoagulant. However, sodium concentrations in serum and plasma decreased significantly in samples without anticoagulant stored at 4°C and 25°C and in heparinized samples stored at 4°C. In Burmese mountain tortoises, potassium concentrations in serum and plasma increased significantly with time in samples without anticoagulant and in heparinized samples stored at 4°C and 25°C, but the increases were less at 4°C. Sodium concentrations in serum and plasma decreased significantly in blood without anticoagulant and heparinized blood stored at 4°C and 25°C.
Conclusions: Storage of blood samples with and without anticoagulant at 4°C significantly improved the stability of potassium and sodium concentrations in both species of tortoises. Early separation of red cells from serum or plasma after blood collection is especially important to ensure the reliability of potassium measurements.     

Artifactual changes in PCV, hemoglobin concentration, and cell counts in bovine, caprine, and porcine blood stored at room and refrigerator temperatures

BACKGROUND: Blood samples collected from farm animals for hematology testing may not reach the laboratory or be examined immediately upon collection, and in some cases may need to be transported for hours before reaching a laboratory. OBJECTIVE: The objective of this study was to investigate the artifactual changes that may occur in PCV, hemoglobin (Hgb) concentration, and cell counts in bovine, caprine, and porcine blood samples stored at room (30 degrees C) or refrigerator (5 degrees C) temperature. METHODS: Baseline values for PCV, Hgb concentration, and RBC and WBC counts were determined immediately after blood collection from 36 cattle, 32 goats, and 48 pigs using manual techniques. Blood samples were split into 2 aliquots and stored at 30 degrees C or 5 degrees C. Hematologic analyses were carried out at specified intervals during 120 hours of storage. Results were analyzed by repeated measure ANOVA; results at different temperatures were compared by paired t-tests. RESULTS: Compared to baseline values, there were no significant changes in Hgb concentration, RBC count, or WBC count in samples from cattle; in Hgb concentration and RBC count in samples from goats; and in Hgb concentration and WBC count in samples from pigs throughout the 120 hours of storage at both 30 degrees C and 5 degrees C. Significant changes (P <.05) from baseline occurred in PCV after 14 hours of storage at 30 degrees C and after 19 hours of storage at 5 degrees C in cattle and goats; and after 10 hours of storage at 30 degrees C and 14 hours of storage at 5 degrees C in pigs. Significant changes also were observed in Hgb concentration at 96 hours at 30 degrees C and 5 degrees C, and in RBC counts at 48 hours at 30 degrees C and 96 hours at 5 degrees C in porcine samples; and in total WBC counts at 120 hours at 30 degrees C and 5 degrees C in caprine samples. Artifactual changes were more pronounced in the samples stored at 30 degrees C. CONCLUSIONS: At both 30 degrees C and 5 degrees C, blood samples from cattle and goats can be stored for up to 12 hours, while blood samples from pigs can be stored for up to 8 hours without any significant changes in PCV. Blood samples from all 3 species can be stored for more than 24 hours without significant changes in Hgb concentration, RBC count, and total WBC count.     

Effect of storage on measurement of ionized calcium and acid-base variables in equine, bovine, ovine, and canine venous blood.

The stability of blood ionized calcium (Ca2+) and acid-base variables in equine, bovine, ovine, and canine venous blood samples (n = 15, in each group) stored at 4 C for 3, 6, 9, 24, or 48 hours was studied. Variables included blood Ca2+ and standard ionized calcium (Ca2+ corrected to pH 7.4) concentrations, pH, blood carbon dioxide and oxygen tensions, base excess, bicarbonate concentration, and total carbon dioxide content. Results indicate that storage of blood samples at 4 C for up to 48 hours, despite appreciable acid-base changes, is associated with less than 1.5% change in equine, bovine, and ovine blood Ca2+ concentrations. Similar changes were observed in canine blood during the first 9 hours' storage. After 24 and 48 hours' storage, clinically relevant decrease (10.5 and 15.5%) in canine blood Ca2+ concentration was measured. Therefore, Ca2+ concentration in equine, bovine, and ovine venous blood samples stored up to 48 hours, and in canine blood samples stored up to 9 hours at 4 C is of diagnostic use.     

Storage of equine red blood cells as a concentrate

The study was undertaken to determine how equine red blood cells (RBCs) survive in storage bags designed for use with human RBCs. Separated RBCs were stored in a routine manner for 35 days and examined every 7 days for storage lesions. Measured parameters included haematology, haemolysis, pH, potassium, lactate, adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG). All tests were performed in vitro. Haematology did not change significantly. Haemolysis increased during storage but did not exceed human limits. pH and 2,3-DPG decreased, while lactate, potassium and ATP increased. RBCs deteriorated somewhat during storage, but when compared with human in vitro parameters, remained suitable for transfusion. It is concluded that equine erythrocytes can be stored for at least 35 days before transfusion.     

The Effects of Active Peripheral Skin Warming on Perioperative Hypothermia in Dogs

Objective — This study evaluates the efficacy of three perioperative warming protocols to improve control of body temperature in anesthetized dogs.
Study Design — A randomized controlled clinical trial.
Animals or Sample Population — Thirty-two client-owned dogs.
Methods — We prospectively studied dogs entering the University of Pennsylvania Veterinary Teaching Hospital for orthopedic or dental procedures and assigned them to one of three perianes-thetic warming protocols. Group 1 (n = 10) had a single circulating warm water mattress applied over the trunk (single-trunk warming). Group 2 (n = 12) had two circulating warm water mattresses, one placed over and one under the trunk (double-trunk warming). Group 3 (n = 10) had warm circulating mattresses applied only around the feet and legs of all available limbs (peripheral warming). The warm water mattresses were prewarmed and maintained at 40°C (104°F) and applied immediately after induction of general anesthesia. All dogs had a layer of thick terry cloth toweling beneath and above the trunk. Body temperature measurements were recorded every 15 minutes for the first 2.5 hours of anesthesia.
Results — The lowest mean temperature for dogs in group 3 was 37.4 ± 0.2°C (99.5°F), compared with 36.4 ± 0.2°C (97.4°F) and 36.7 ± 0.2°C (98.0°F) in groups 1 and 2, respectively.
Conclusions — Dogs in the peripheral warming group maintained significantly higher core body temperatures than dogs in either trunk warming groups throughout the 2.5-hour study period.
Clinical Relevance — To maintain body heat in dogs during anesthesia, it is more effective to warm the feet and legs than to warm the trunk.     

Effects of syringe material and temperature and duration of storage on the stability of equine arterial blood gas variables

OBJECTIVES: To evaluate the consistency of partial pressures (P) of arterial oxygen (aO(2)), arterial carbon dioxide (aCO(2)) and pH measurements in equine carotid arterial blood samples taken into syringes made from three different materials and stored at room temperature or placed in iced water for measurement at three different times. STUDY DESIGN: Prospective observational study over 19 days. ANIMALS: Four clinically normal Thoroughbred or Thoroughbred-cross horses (three geldings, one mare, mean age 6.25 years, range 5-7 years). METHODS: Identical blood samples were taken on two separate occasions from the carotid arteries of the four horses into syringes made of glass, plastic and polypropylene. PaO(2), PaCO(2) and pH determinations were performed on blood from each syringe type at 10, 60 and 120 minutes post-sampling with samples stored at room temperature (approximately 20 degrees C) or in iced water (approximately 0 degrees C). Data were analysed by anova and a split plot model fitting syringe within horse X pair and time within temperature within syringe. RESULTS: Syringe material, storage temperature and time before analysis all had significant effects on PaO(2) (p < 0.001). PaCO(2) was unaffected by syringe material or storage temperature. However, over 120 minutes, storage duration significantly (p = 0.002) affected values. Temperature of storage and duration prior to analysis both significantly affected pH values (p = 0.005 and p < 0.001, respectively), but syringe material did not. Several significant interactions between these variables were noted. CONCLUSIONS: Equine arterial blood gas determination has a different sensitivity to storage conditions compared to other veterinary species. CLINICAL RELEVANCE: For accurate equine arterial blood analysis, PaO(2) samples need to be analysed within 10 minutes or taken into glass syringes, stored on ice and analysed at 2 hours post-sampling. PaCO(2) and pH measurements can be performed on samples stored in glass, plastic or polypropylene syringes at room temperature for up to 1 hour post-sampling.     

Alterations in normal canine platelets during storage in EDTA anticoagulated blood

Abstract: Flow cytometric detection of platelet surface-associated IgG (PSAIgG) can be used to determine whether immunologic factors are contributing to thrombocytopenia in dogs. In vitro alterations in platelet activation and morphology, however, could impact the results of this test. The purpose of this study was to determine whether the PSAIgG test for immune-mediated thrombocytopenia was valid on whole blood in EDTA anticoagulant after 24–72 hours of storage, and to characterize other alterations in canine platelets that could impact immunologic testing. Platelets were harvested and analyzed immediately after blood collection and after 24, 48, and 72 hours of storage at 4°C. Spontaneous and thrombin-induced changes in the following platelet parameters were evaluated using flow cytometric techniques: PSAIgG, platelet microparticle formation, membrane expression of P-selectin and glycoprotein CD61, exogenous IgG binding, surface-exposed phosphatidylserine, and fibrinogen binding. The amount of PSAIgG increased 6-to 9-fold in stored samples compared with fresh samples. Platelet microparticle formation was spontaneous in stored samples and increased significantly over time. Membrane phosphatidylserine, P-selectin, and fibrinogen binding were not altered by storage, indicating that platelet activation was minimal in stored samples. Although storage decreased the percentage of platelets positive for CD61 by 8-to 10-fold compared with fresh samples, activation by high-dose thrombin partially restored the percentage of CD61-positive platelets in 24-hour-old samples. In conclusion, even though platelets stored in EDTA for up to 72 hours remain in a resting state, aged platelets have an increased tendency to form microparticles and have increased surface IgG and decreased surface CD61, which may contribute to false-positive results for tests of immune-mediated thrombocytopenia.     

Use of a prestorage leukoreduction filter effectively removes leukocytes from canine whole blood while preserving red blood cell viability

Leukoreduction of blood products is a technique used to prevent leukocyte-induced transfusion reactions. Filters currently used for human blood products achieve at least a 99.9% reduction in leukocyte numbers per unit (450 mL) of blood. Goals of this study were to determine if a prestorage leukoreduction filter could effectively achieve leukoreduction of canine blood and to determine if viability of the leukoreduced red blood cell (RBC) product could be maintained after 35 days of storage. Blood collected from each dog was filtered through a leukoreduction filter at either room temperature or after cooling (4 degrees C) for 4 hours. Filtration efficacy was determined by measurement of pre- and postfiltration leukocyte counts. In vitro viability of RBCs was determined by comparing RBC adenosine triphosphate concentration and percent hemolysis before and after the storage period. In vivo viability of stored cells was determined using a biotin-streptavidin-phycoerythrin labeling technique and flow cytometry. Blood filtered within 30 minutes of collection versus blood filtered after cooling had mean reductions in leukocyte numbers of 88.90 and 99.99%, respectively. The mean ATP and hemoglobin concentrations from the in vitro analysis were comparable to those obtained in previously for canine RBC adequately stored for 35 days. The mean in vivo 24-hour survival of the stored RBC was 84.7%. The leukoreduction filter used did not adversely affect in vitro or in vivo viability of canine RBCs. The filter effectively removed leukocytes from blood, with maximal efficiency of filtration achieved with use of cooled blood.     

Dissipation of Heat During Polymerization of Acrylics Used for External Skeletal Fixator Connecting Bars

Objective — To determine the amount of heat conducted by transfixation intramedullary pins (IP) and Kirschner wires (KW) during polymerization of acrylics used for external skeletal fixator (ESF) connecting bars.
Study Design — Thermal conduction was measured using thermistors applied to IP and KW surfaces during the polymerization phase of acrylics.
Methods — Type II ESF were created from IP or KW placed into wooden dowels and plastic tubing used to create connecting bars filled with one of two types of acrylic (Acrylic Pin External Fixation System or Technovit, Jorgensen Laboratories, Loveland, CO). Thermistors were positioned on the acrylic column surface and on IP or KW surfaces 5 or 10 mm from the acrylic column. Five ESF test groups were created. The maximum temperature (Tmax) of the acrylic column (Tmax-A), IP (Tmax-IP), KW (Tmax-KW), and duration that Tmax-IP or Tmax-KW remained greater than or equal to 55°C were calculated.
Results — All IP and KW thermistors placed 5 mm from acrylic columns reached mean temperatures greater than 50°C and had peak temperature ranges greater than 55°C compared with all IP and KW thermistors placed 10 mm from the acrylic columns in all groups. Thermistors placed 5 mm from the acrylic column in two groups maintained temperatures greater than 55°C for greater than or equal to 0.5 minutes.
Conclusions — Acrylic columns positioned 5 mm from a thermistor on a IP or KW had the potential to reach or exceed temperatures that have been reported to cause thermal necrosis of tissues.
Clinical Relevance — Acrylic Pin External Fixation System or Technovit acrylic connecting bars used in ESF designs have the potential to cause thermal injury to soft and bony tissue by thermal conduction along transfixation pins or wires.     

Effect of temperature,storage time,and sample type on sorbitol dehydrogenase activity in llama serum and plasma

Abstract: Serum and heparinized plasma samples were collected from 11 adult, clinically healthy llamas. Aliquots were assayed for sorbitol dehydrogenase (SDH) activity after storage at room temperature (20°C), 4°C, or −20°C for defined time intervals up to 1 week postcollection. Sorbitol dehydrogenase activity in all samples was within reference intervals for our laboratory. No difference was found between serum and plasma SDH activity when measured immediately (within 1 hour) after collection. Sorbitol dehydrogenase activity decreased to 79% of initial activity by 24 hours in serum stored at room temperature; plasma had 94% of initial SDH activity under the same conditions. Sorbitol dehydrogenase activity was stable in both plasma and serum stored for up to 1 week at 4°C or −20°C. With the exception of serum stored at 20°C for > 8 hours, in vitro stability of llama SDH was adequate for its use in diagnostic testing.     

Incidence of Transfusion Reactions and Retention of Procoagulant and Anticoagulant Factor Activities in Equine Plasma

Background: The extent of preservation of clotting factors and incidence of transfusion reactions to noncommercial equine plasma is not documented.
Hypothesis: Equine frozen plasma would retain its coagulation factor activity within the reference range and the incidence of transfusion reactions would be low.
Animals: Ten plasma donor horses. Fifty clinically ill hospitalized horses receiving plasma were reviewed to determine the incidence of reactions.
Methods: In vitro study and retrospective case review. Plasma was prepared by gravity sedimentation from whole blood refrigerated for 48 hours. The activities of factors VII through XII, antithrombin (AT), and Protein C were measured. Factor activities were compared for plasma samples obtained before blood collection (S0), after 48 hours of gravity sedimentation at 5 °C and after plasma separation (S1), and after 90 days of storage at −20 °C (S90). The medical records of 50 consecutive clinically ill horses receiving frozen plasma were reviewed to determine the incidence of transfusion reactions.
Results: The combined effect of plasma harvest, gravity sedimentation, decantation, and freezing caused significant reductions in factors IX, (43% P = .0013), X, (33% P = .0001), XI, (48% P = .0008), AT, (10% P = .02), and Protein C (26% P = .0001). Activities for all factors analyzed, except factor X, remained within the reference ranges. Transfusion reactions were recorded for 5/50 horses.
Conclusions and Clinical Relevance: Clotting factors, AT, and Protein C were well preserved. The incidence of reactions to frozen plasma was 10%.     

EXAMINATION OF STOCKFEEDS FOR SALMONELLA

SUMMARY Of 100 stockfeeds examined for Salmonella 45 were positive by pre-enrichment followed by selective enrichment of 10 times 25 g samples. Forty-three were positive by selective enrichment of pooled aliquots of the pre-enrichment broths from the 10 times 25 g samples.
Aliquots of the pre-enrichment broths from the 10 times 25 g samples of 77 of the feeds were stored at 4°C and retested after 6 days. One hundred and ten of these (770) subsamples were found to contain salmonellas initially, and 107 were found to contain salmonellas after storage for 6 days.
The testing of feeds by the examination of multiple 25 g samples and pooled pre-enrichment broths is recommended. Aliquots of the pre-enrichment broths may be stored at 4°C for 6 days and retested if an estimation of the numbers in the feed is required. Further pre-enrichment after cold storage is not required.     

Equine immune-mediated hemolytic anemia associated with Clostridium perfringens infection

Background: Previous studies have suggested an association between equine immune-mediated hemolytic anemia and clostridial infections or neck abscesses.
Objective: The purpose of this report was to describe and characterize the hematologic abnormalities in a horse with Clostridium -associated immune-mediated hemolytic anemia. We also retrospectively evaluated hematologic abnormalities in 8 horses with clostridial myositis or subcutaneous emphysema.
Methods: A 7-year-old Foreign Warm-Blood gelding was evaluated for anemia and a cervical abscess. CBCs and reticulocyte counts were obtained using an Advia 120 analyzer and evaluation of Wright's-stained smears. All cases of equine Clostridium spp. myositis or subcutaneous emphysema over a 7-year period were identified in a retrospective search of the University of Minnesota Veterinary Teaching Hospital database. Clinical, hematologic, and microbiological findings were recorded.
Results: Clostridium perfringens genotype A was isolated from the neck wound of the gelding. The CBC was characterized by severe regenerative anemia, intravascular hemolysis, and RBC agglutination. A direct Coombs' test was positive. Moderate numbers of spheroechinocytes were observed. The total automated reticulocyte count was 4.5% (56,700/μL), with most reticulocytes having low absorbance (mature reticulocytes). The anemia responded to penicillin and steroidal and nonsteroidal immunosuppressive drugs. Of 8 horses with myositis, all of which involved the cervical region, 5 were anemic, 1 had a positive direct Coombs' test, and 2 had increased numbers of type III echinocytes and spheroechinocytes.
Conclusions: The presence of type III echinocytes or spheroechinocytes may be helpful in diagnosing immune-mediated hemolytic anemia associated with clostridial infections in horses. Automated reticulocyte counts may detect very low levels of reticulocytosis in hemolytic anemia in horses.     

Effects of fecal collection and storage factors on strongylid egg counts in horses

Fecal analyses are becoming increasingly important for equine establishments as a means of parasite surveillance and detection of anthelmintic resistance. Although several studies have evaluated various egg counting techniques, little is known about the quantitative effects of pre-analytic factors such as collection and storage of fecal samples. This study evaluated the effects of storage temperature, storage time and airtight versus open-air storage on fecal egg counts. The experimental protocols were replicated in two study locations: Copenhagen, Denmark and Athens, Georgia, USA. In both locations, the experiment was repeated three times, and five repeated egg counts were performed at each time point of analysis. In experiment A, feces were collected rectally and stored airtight at freezer (−10 to −18 °C), refrigerator (4 °C), room (18–24 °C), or incubator (37–38 °C) temperatures. Egg counts were performed after 0, 6, 12, 24, 48, and 120 h of storage. In experiment B, feces were collected rectally and stored airtight or in the open air in the horse barn for up to 24 h. Egg counts were performed after 0, 3, 6, 12, and 24 h of storage. In experiment A at both locations, samples kept in the refrigerator showed no decline in egg counts, whereas storage in the freezer and incubator led to significantly declining egg numbers during the study. In contrast, storage at room temperature yielded marked differences between the two study locations: egg counts remained stable in the U.S. study, whereas the Danish study revealed a significant decline after 24 h. In experiment B, the Danish study showed no differences between airtight and open-air storage and no changes over time, while the U.S. study found a significant decline for open-air storage after 12 h. This difference was attributed to the different barn temperatures in the two studies. To our knowledge, this is the first study to evaluate the pre-analytic factors affecting egg counts in horses using an experimental protocol replicated in two contrasting geographic and climatic locations. Our results demonstrate that refrigeration is the best method for storage of fecal samples intended for egg count analysis, but that accurate results can be derived from fecal samples collected from the ground within 12 h of passage.     

Proliferation of Streptococcus zooepidemicus and Pseudomonas aeruginosa within a simulated subpalpebral lavage flushed with equine serum

Objective  To evaluate whether equine serum administered via a simulated subpalpebral lavage system (SPL) supports proliferation of Streptococcus zooepidemicus or Pseudomonas aeruginosa within the tubing.
Procedures  A sterile i.v. catheter with injection cap was inserted into sterilized silicone tubing (Mila^®). To mimic an SPL within the dorsal conjunctival fornix, the tubing was secured to an elevated platform. The tip of the tubing extended from the platform into a vial containing culture medium just inoculated with approximately 1.5 × 10⁸ CFU/mL P. aeruginosa or S. zooepidemicus . To mimic administration of medication, the tubing was infused twice daily with equine serum, sterile saline (negative control), or culture medium (positive control) followed by air. Incubation was at 25 or 37 °C. At 24, 48, and 72 h postinoculation, samples were obtained for bacterial culture from one simulated SPL for each experimental variant. The following sections were cultured: (i) tubing tip previously submerged in the inoculated culture medium, (ii) tubing mid-section, and (iii) tip of the i.v. catheter. The experiment was performed in triplicate.
Results  Streptococcus zooepidemicus or P. aeruginosa were isolated from 100% of the tubing tips. Streptococcus zooepidemicus was isolated from one mid-section flushed with culture medium incubated at 37 °C. All other samples were negative for growth of the inoculated agents.
Conclusions  Streptococcus zooepidemicus and P. aeruginosa did not proliferate within silicone tubing infused with equine serum. These data suggest that topical serum can be safely administered through a superiorly placed SPL in clinical cases.     

Comparison of 4 blood storage methods in a protocol for equine pre-operative autologous donation

OBJECTIVE: To compare viability of equine whole blood stored by 4 different methods, and to establish optimal storage protocols for an equine autologous blood donation program. STUDY DESIGN: In vitro study of stored equine whole blood. Animals- Six healthy adult horses. METHODS: Blood from each horse was collected into 4 different containers: glass bottles containing acid-citrate-dextrose solution (ACD), plastic bags containing ACD, citrate-phosphate-dextrose (CPD), and CPD with supplemental adenine (CPDA-1). Blood was stored for 5 weeks and sampled at 2-day intervals. Standard hematologic and biochemical variables were evaluated, and adenosine-5-triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) concentrations were measured and normalized to total hemoglobin content. RESULTS: Plasma hemoglobin, % hemolysis, lactate, potassium, ammonia, and lactate dehydrogenase (LDH) increased, whereas glucose concentration and pH decreased in all stored blood over 5 weeks. There was a temporal increase in hemolysis with all storage methods, but the increase was greatest in glass bottles. Lactate and ammonia were highest in CPD and CPDA-1 samples, indicating more active red blood cell (RBC) metabolism. 2,3-DPG concentrations decreased during storage, but were optimally preserved with CPDA-1. ATP concentrations were significantly higher for blood stored in CPDA-1, and were lowest in glass bottles. CONCLUSIONS: Hematologic and biochemical values measured for blood stored in CPDA-1 are suggestive of improved RBC viability compared with other storage methods. With the exception of ATP, results from stored equine blood were similar to those reported for other species. CLINICAL RELEVANCE: Commercial CPDA-1 bags appear to be the optimal storage method for equine whole blood.     

The Effect of Triple Pelvic Osteotomy on the Articular Contact Area of the Hip Joint in Dysplastic Dogs: An in Vitro Experimental Study

Objective —To investigate the effect of triple pelvic osteotomy (TPO) on articular contact area and acetabular coverage of dysplastic hip joints in dogs.
Study Design —Articular contact area and femoral head coverage by the acetabulum were computed in vitro in normal and dysplastic canine hips. The effect of TPO on articular contact and coverage was then analyzed in the dysplastic hips.
Sample Population—Five normal and six dysplastic canine cadaver specimens.
Methods —Contact area and coverage of loaded hips were computed using serial computed tomography scan images before and after TPO. Three angles of acetabular ventroversion (AVV) were studied (20°, 30°, and 40°). Using a custom-designed hinge plate, angles of spontaneous hip reduction in dysplastic hips were compared with previously recorded angles of reduction determined by the Ortolani test.
Results —Contact area significantly increased from 0° to 30° of AVV, then remained virtually unchanged. Coverage significantly increased from 0° to 20° of AVV. Both contact and coverage of normal hips were similar, yet significantly smaller than those of dysplastic hips once reduction had occurred. The experimental angles of reduction were significantly smaller and poorly correlated with the angles of reduction determined by the Ortolani test. Although coverage continued to increase with AVV, the actual joint contact area did not significantly vary after relocation of the femoral head.
Conclusions —This study suggests that increasing AVV beyond 20° does not significantly improve the beneficial effects of TPO and therefore should be carefully weighed against increased risks of postoperative complications associated with large angles of AVV.     

Validation of a Commercially Available Immunoassay for the Measurement of Bovine Cardiac Troponin I

Background: Commercially available cardiac troponin I (cTnI) assays developed for use in humans have not yet been validated for use in cattle.
Hypotheses: The ADVIA Centaur TnI-Ultra immunoassay can be used for the detection of bovine cTnI. In healthy cattle, serum cTnI is undetectable or is present only in trace amounts.
Methods: Purified bovine cTnI and cTnI-free bovine serum were used for the evaluation of assay performance including intra- and inter-assay precision, sensitivity, interference, linearity, and recovery. Effects of storage at 23, 4, −20, and −80 °C for 2 days, and at −20 and −80 °C for 7 and 14 days and repeated freeze-thaw cycles on recovery of cTnI were analyzed. Serum cTnI concentrations in 30 healthy dairy cows were determined.
Results: Intra- and inter-assay precisions (mean ± SD) were 4.48 ± 2.26 and 13.36 ± 6.59%, respectively. The assay demonstrated linearity at 0.5, 2, 15, and 30 ng/mL cTnI. Mean recovery was 100.81, 85.26, 87.72, and 114.42%, respectively. Skeletal muscle homogenate added to serum of known cTnI concentration did not alter the concentration of the analyte ( P > .05). Concentration of cTnI significantly decreased when samples were stored at 4 and 23 °C for 2 days ( P < .05). Repeated freeze-thaw cycles and storage at −20 °C for 7 days had no significant influence on cTnI concentration ( P > .05). Serum cTnI concentration in healthy cattle was ≤0.03 ng/mL.
Conclusion and Clinical Importance: ADVIA Centaur can be used reliably for the detection of serum cTnI concentration in cattle.     

Stability of hematologic analytes in monkey, rabbit, rat, and mouse blood stored at 4°C in EDTA using the ADVIA 120 hematology analyzer

Background: The time from sampling to analysis can be delayed when blood samples are shipped to distant reference laboratories or when analysis cannot be readily performed. Objective: The objective of this study was to evaluate the stability of hematologic analytes in blood samples from monkeys, rabbits, rats, and mice when samples were stored for up to 72 hours at 4°C. Methods: Blood samples from 30 monkeys, 15 rabbits, 20 rats, and 30 mice were collected into EDTA‐containing tubes and were initially analyzed within 1 hour of collection using the ADVIA 120 analyzer. The samples were then stored at 4°C and reanalyzed at 24, 48, and 72 hours after collection. Results: Significant (P<.0003) changes in hematologic analytes and calculations included increased HCT and MCV and decreased MCHC and cell hemoglobin concentration mean (CHCM) at 72 hours and increased MPV at 24 hours in monkeys; increased MCV at 72 hours and MPV at 48 hours and decreased monocyte count at 24 hours in rabbits; increased MCV and decreased MCHC, CHCM, and monocyte count at 24 hours in rats; increased MCV, red cell distribution width, and MPV and decreased MCHC, CHCM, and monocyte count at 24 hours in mice. Conclusions: Although most of the changes in the hematologic analytes in blood from monkeys, rabbits, rats, and mice when samples were stored at 4°C were analytically acceptable and clinically negligible, the best practice in measuring hematologic analytes in these animals is timely processing of blood samples, preferably within 1 hour after collection.