Pre- and Post-Transfusion Alloimmunization in Dogs Characterized by 2 Antiglobulin-Enhanced Cross-match Tests

Evaluation of post-transfusion RBC alloimmunization in dogs using a gel-column crossmatch with and without anti-canine globulin enhancement

A blood crossmatch is essential to ensure RBC compatibility for previously transfused dogs. There is no gold standard crossmatch method for dogs, although the standards used most commonly by academic institutions and reference laboratories are the tube and gel-column crossmatches. Addition of anti-canine globulin (ACG) has been suggested to increase detection of RBC incompatibilities. Our objective was to determine if there is a correlation between results of a standard and an ACG-enhanced gel-column crossmatch in detecting post-transfusion RBC alloimmunization. Pre- and post-transfusion serum or plasma samples were obtained from 33 dogs for major crossmatches to 1-6 (median: 3) blood donors. Crossmatches were performed with (n = 202) and without (n = 202) ACG, with results scored by 4 observers, 3 of whom were anonymized. Ten of 33 (30%) dogs had major crossmatch incompatibilities post-transfusion. RBC incompatibilities (2-4+ agglutination) were detected only with ACG in 4 dogs, only without ACG in 3 dogs, and with both methods in 3 dogs. There was fair correlation between crossmatch methods for determination of compatibility (ρ = 0.34; p < 0.001) and incompatibility (ρ = 0.35; p < 0.001) scores. Among 4 observers, there was near-perfect agreement in determining compatibility (κ = 0.97; p < 0.001) and substantial agreement in overall scoring of incompatibility (κ = 0.77; p < 0.001). Our results suggest that detection of RBC incompatibilities in dogs can be maximized by performing a gel-column crossmatch both with and without ACG enhancement.

Effect of donor blood storage on gel column crossmatch in dogs

BACKGROUND

Compared with fresh blood, stored equine donor blood results in spurious tube crossmatch incompatibilities. Interpretation of blood crossmatch results is considered subjective.

OBJECTIVES

We aimed to determine if the duration of canine donor blood storage impacts compatibility testing using a standard gel column crossmatch and evaluate interobserver variation in the interpretation of crossmatch results.

METHODS

Observational study. Whole blood segments were obtained from 23 canine packed red blood cell (RBC) units for use in crossmatches after storage for 0, 7, 14, 21, 28, and 35 days. Major and minor crossmatches were performed using serum and RBCs, respectively, from two to three healthy "recipient" dogs per unit. All crossmatch results were interpreted by four observers, of whom three were blinded.

RESULTS

All major crossmatches (n = 61) were compatible on day 0 and remained compatible through day 35 of storage. All minor crossmatches (n = 69) were compatible at all time points, except for five donor pairs with 1 to 3+ agglutination. Repeat testing of these five donor pairs confirmed crossmatch incompatibilities on days 0 through 35, with no change in the degree of incompatibility over time. There was substantial agreement among four observers in determining compatibility (κ = 0.94) and scoring incompatibility (κ = 0.76).

CONCLUSIONS

The current practice of performing canine crossmatches with whole blood segments stored for up to 35 days is acceptable, with no spurious changes in compatibility expected over time. The substantial interobserver agreement suggests that the gel column is suitable for performing canine crossmatches in a laboratory setting with multiple personnel.

Validation of a cage-side agglutination card for Dal blood typing in dogs

BACKGROUND

Although 98% of the canine population is Dal-positive, Dal-negative dogs are more common in some breeds such as Doberman Pinschers (42.4%) and Dalmatians (11.7%), and finding compatible blood for these breeds may be challenging, given limited access to Dal blood typing.

OBJECTIVES

To validate a cage-side agglutination card for Dal blood typing and determine the lowest packed cell volume (PCV threshold) at which interpretation remains accurate.

ANIMALS

One-hundred fifty dogs, including 38 blood donors, 52 Doberman Pinschers, 23 Dalmatians and 37 anemic dogs. Three additional Dal-positive canine blood donors were included to establish the PCV threshold.

METHODS

Dal blood typing was performed on blood samples preserved in ethylenediaminetetraacetic acid (EDTA) <48 hours using the cage-side agglutination card and a gel column technique (gold standard). The PCV threshold was determined using plasma-diluted blood samples. All results were read by 2 observers, blinded to each other's interpretation and to the sample's origin.

RESULTS

Interobserver agreement was 98% and 100% using the card and gel column assays, respectively. Overall, the sensitivity and specificity of the cards were 86%-87.6% and 96.6%-100%, respectively, depending on the observer. However, 18 samples were mistyped using the agglutination cards (15/18 by both observers): 1 false-positive (Doberman Pinscher), and 17 false-negative samples including 13 anemic dogs (PCV range, 5%-24%; median, 13%). The PCV threshold allowing reliable interpretation was determined to be >20%.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dal agglutination cards are reliable as a cage-side test, but results should be interpreted cautiously in severely anemic patients.

Alloimmunization in dogs after transfusion: A serial cross-match study

BACKGROUND

Cross-matching is performed to determine the serological compatibility of donor and recipient blood. Current guidelines recommend that cross-matching should be performed in dogs when an initial transfusion was performed more than 4 days ago or when the transfusion history is unknown.

HYPOTHESIS

Determination at what time point alloantibodies are detected in dogs after transfusion. The hypothesis was that dogs would form alloantibodies within 4 days after a transfusion.

ANIMALS

Twenty-one anemic dogs were transfused and monitored for at least 4 subsequent days. Exclusion criteria were persistent red blood cell (RBC) agglutination and a previous transfusion.

METHODS

Prospective observational study. Cross-matching was performed before the initial DEA 1-compatible transfusion and on days 1, 2, 3, and 4 and if possible, between day 5 and 28, using the tube method without enhancement (major cross-match, recipient controls); recipients were monitored for transfusion reactions.

RESULTS

In 12/21 dogs a positive cross-match (microscopic degree of agglutination [AD] 1+ to 2+) was observed within 4 days after the transfusion. In a nonlinear regression model, no significant association was detected between type of anemia (P = .41), RBC storage time (P = .44), immunosuppressive treatment (P = .75) nor transfusion volume (P = .70) and the occurrence of positive cross-matches within 4 days after transfusion. Another 4 dogs developed a positive cross-match (microscopic AD 1+ to 2+) after 6 to 13 days.

CONCLUSIONS AND CLINICAL IMPORTANCE

Because production of alloantibodies was detected as early as 1 day after transfusion, cross-matching should be performed before every subsequent transfusion.

Comparison of a commercial immunochromatographic strip crossmatch kit and standard laboratory crossmatch methods for blood transfusion compatibility in dogs

OBJECTIVE

To evaluate agreement between 2 standard laboratory (SL) methods and an immunochromatographic strip (ICS) method to crossmatch dogs receiving RBC transfusions. A second objective was to evaluate uninterpretable SL crossmatch results as compared to ICS in the presence of autoagglutination.

DESIGN

Prospective observational study (September 2018 to October 2019).

SETTING

University teaching hospital.

ANIMALS

Forty anemic dogs receiving RBC transfusions.

INTERVENTIONS

None.

MEASUREMENT AND MAIN RESULTS

All dogs received DEA 1-negative packed RBCs. Three crossmatch methods were evaluated against the same unit transfused to each dog: SL method performed at institutional laboratory (SL-I), SL method sent to a commercial laboratory (SL-C), and a commercially available point-of-care ICS method. Major and minor crossmatches were incompatible for 2.5%/7.5% of ICS tests, 82.5%/52.5% of SL-I tests, and 52.5%/27.5% of SL-C tests. Agreement between ICS and SL-C major (κ = 0.05) and minor (κ = 0.02) crossmatches and between ICS and SL-I major (κ = 0.009) and minor (κ = 0.03) crossmatches was slight. Agreement between SL-C and SL-I major (κ = -0.06) and minor (κ = -0.12) crossmatches was poor. Results of major and minor crossmatches were uninterpretable due to autoagglutination in 38%/38% for SL-I and 29%/18% for SL-C crossmatches. ICS method was interpretable for 93% (major) and 98% (minor) crossmatches. After exclusion of uninterpretable SL pairings, agreement still remained poor to slight between all tests. Only 1 of 40 dogs (2.5%; 95% confidence interval: <1.0%-13.2%) had an immediate immunological transfusion reaction.

CONCLUSIONS

Lack of agreement between all methodologies was noted. The high level of incompatibility predicted by SL methods despite lack of clinically relevant reactions suggests a high false incompatibility rate as compared to the ICS test. ICS testing was also able to give results more frequently in the face of autoagglutination. Further work is needed to investigate the ICS method's ability to predict clinically significant transfusion reactions.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS). Part 1: Definitions and clinical signs

OBJECTIVE

To use a systematic, evidence-based consensus process to develop definitions for transfusion reactions in dogs and cats.

DESIGN

Evidence evaluation of the literature was carried out for identified transfusion reaction types in dogs and cats. Reaction definitions were generated based on synthesis of human and veterinary literature. Consensus on the definitions was achieved through Delphi-style surveys. Draft recommendations were made available through industry specialty listservs and comments were incorporated.

RESULTS

Definitions with imputability criteria were developed for 14 types of transfusion reactions.

CONCLUSIONS

The evidence review and consensus process resulted in definitions that can be used to facilitate future veterinary transfusion reaction research.

Accuracy of a point-of-care major crossmatch test and risk factors for major crossmatch incompatibility in cats

Major crossmatch testing can help identify immunologic incompatibilities between blood donors and recipients; however, there are limited studies describing the accuracy of point-of-care crossmatch tests. The first aim of this study was to determine if a gel-based, point-of-care major crossmatch method (GEL-CM), without antiglobulin-enhancement, could accurately detect compatible and incompatible donor-recipient pairings, using an antiglobulin-enhanced laboratory-based major crossmatch method (LAB-CM) as the reference standard. The second aim was to describe the incidence of, and risk factors for, major crossmatch incompatibility in cats. Nineteen previously-transfused cats and 32 transfusion-naïve cats, representing 132 unique donor-recipient pairings, were included in this study. Both LAB-CM and GEL-CM tests were performed for most parings. There was poor agreement between the LAB-CM and GEL-CM results (kappa = 0.111; 95% confidence interval [CI], -0.093 to 0.314). Transfusion-naïve cats had incompatibility rates of 3% and 6% using LAB-CM and GEL-CM, respectively; previously-transfused cats had incompatibility rates of 32% and 26% using LAB-CM and GEL-CM, respectively. History of previous transfusion was the only identified cat risk factor for an incompatible LAB-CM (odds ratio [OR], 31.0; 95% CI, 3.77-254.98; P = 0.0019) and GEL-CM (OR, 5.7; 95% CI, 1.72-19.20; P = 0.0054). Further studies are needed to determine if GEL-CM can detect clinically-relevant immunologic incompatibilities that would result in transfusion reactions. Major crossmatch testing is of greater importance in cats that have previously received a transfusion.

Association of Veterinary Hematology and Transfusion Medicine (AVHTM) Transfusion Reaction Small Animal Consensus Statement (TRACS) Part 2: Prevention and monitoring

OBJECTIVE

To systematically review available evidence to develop guidelines for the prevention of transfusion reactions and monitoring of transfusion administration in dogs and cats.

DESIGN

Evidence evaluation of the literature (identified through Medline searches through Pubmed and Google Scholar searches) was carried out for identified transfusion reaction types in dogs and cats. Evidence was evaluated using PICO (Population, Intervention, Comparison, Outcome) questions generated for each reaction type. Evidence was categorized by level of evidence (LOE) and quality (Good, Fair, or Poor). Guidelines for prevention and monitoring were generated based on the synthesis of the evidence. Consensus on the final recommendations and a proposed transfusion administration monitoring form was achieved through Delphi-style surveys. Draft recommendations and the monitoring form were made available through veterinary specialty listservs and comments were incorporated.

RESULTS

Twenty-nine guidelines and a transfusion administration monitoring form were formulated from the evidence review with a high degree of consensus CONCLUSIONS: This systematic evidence evaluation process yielded recommended prevention and monitoring guidelines and a proposed transfusion administration form. However, significant knowledge gaps were identified, demonstrating the need for additional research in veterinary transfusion medicine.

Identification of 5 novel feline erythrocyte antigens based on the presence of naturally occurring alloantibodies

Background

Since the discovery of the Mik antigen, several studies have described blood incompatibilities unrelated to the AB system in cats.

Objective

To estimate the prevalence of cats with non‐AB incompatibilities associated with naturally occurring alloantibodies (NOAb), and to begin mapping the corresponding feline erythrocyte antigens (FEA).

Animals

Two hundred and fifty‐eight type A cats.

Methods

Prospectively, cats were evaluated for the presence of NOAb by crossmatching in groups of 4‐6 cats. When NOAb were detected in a cat, its plasma was used as reagent to assess for the presence of the corresponding FEA in all cats included thereafter, and agreement observed between results of this extensive blood typing was evaluated.

Results

The chance of detecting incompatibilities by randomly crossmatching 2 cats was 3.9%, which resulted in at least 7% of type A cats having NOAb. Blood typing and agreement analyses performed with 7 newly detected NOAb allowed the identification of 5 presumably distinct FEA. Feline erythrocyte antigens 1 and 5 were most frequent with prevalence of 84% and 96%, respectively. Only FEA 1‐negative status was associated with a higher risk of presenting NOAb; with 16.7% of 42 FEA 1‐negative cats having NOAb compared to 5.1% of 216 FEA 1‐positive cats.

Conclusions and Clinical Importance

This study represents a first step of FEA identification outside the AB system. Because of its prevalence and association with NOAb, FEA 1 might correspond to the Mik antigen.

Accuracy of point-of-care crossmatching methods and crossmatch incompatibility in critically ill dogs

BACKGROUND

The performance of commercial point-of-care crossmatch (CM) tests compared to laboratory tube agglutination CM is unknown. Additionally, there is limited information regarding CM incompatibility in ill dogs.

OBJECTIVES

To determine if point-of-care major CM methods are accurate in detecting compatible and incompatible tests when compared to laboratory CM methods, and to identify factors associated with CM incompatibility in dogs.

ANIMALS

Part 1 (prospective) included 63 client-owned dogs potentially requiring blood transfusion. Part 2 (retrospective) included all dogs from part 1, plus medical records of 141 dogs with major CM results.

METHODS

For part 1, major CM was performed using a tube agglutination assay (LAB-CM), a gel-based point-of-care test (GEL-CM), and an immunochromatographic point-of-care test (IC-CM). For part 2, medical record data were collected to determine rates of and risk factors for CM incompatibility.

RESULTS

Kappa agreement between the LAB-CM and GEL-CM methods could not be calculated due to a relative lack of incompatible results. Kappa agreement between the LAB-CM and IC-CM methods was 0.16 (95% confidence interval [CI] = 0-0.31, P = .007) indicating no agreement. The LAB-CM incompatibility in transfusion-naïve vs dogs that had a transfusion was 25% and 35%, (P = .3).

CONCLUSIONS AND CLINICAL IMPORTANCE

Compared to laboratory methods, point-of-care methods evaluated in our study lacked sensitivity for detecting incompatibilities. Dogs had similar rates of major CM incompatibility regardless of transfusion history. This suggests CM testing prior to transfusion be considered in all dogs however our study did not investigate clinical relevancy of incompatible LAB-CM.

The dog erythrocyte antigen 1 blood group in nondomesticated canids and compatibility testing between domestic dog and nondomesticated canid blood

Background

The dog erythrocyte antigen (DEA) 1 blood group is considered as the most immunogenic and clinically important in dogs. Little is known in nondomesticated canids.

Objectives

To type DEA 1 in nondomesticated captive canids and to evaluate potential interspecific blood transfusions between domestic and nondomestic canids.

Animals

One hundred forty captive nondomesticated canids belonging to 13 species from 19 French zoos, and 63 domestic dogs.

Methods

Prospective study. Blood samples were typed for DEA 1 using immunochromatographic and flow cytometric techniques. A neutral gel column test was used for crossmatching.

Results

Of 140 nondomesticated canids, 72.9% were DEA 1+ and 27.1% were DEA 1− using immunochromatographic technique and 74.3% were DEA 1+ and 25.7% were DEA 1− by flow cytometric technique.

Crossmatch (XM) between 140 nondomesticated canid red blood cells (RBCs) and plasma from a previously DEA 1+ sensitized DEA 1− dog revealed 112 incompatibilities (80%). Crossmatches between 130 nondomesticated canid serum and 1 or up to 8 donor dogs' RBCs revealed 99 of 130 (76%) compatibilities. Crossmatches between 115 nondomesticated canid RBCs and donor dogs' serum revealed 59 of 115 (51%) compatibilities.

Conclusions and Clinical Importance

Dog erythrocyte antigen 1 blood type is present in nondomesticated canids with variable prevalence depending on species. The majority of tested nondomesticated canids appear to have no naturally occurring alloantibodies against domestic dogs' RBCs. Therefore xenotransfusion of blood from domestic dogs can be considered when species specific blood is not available. Cross matching is essential before xenotransfusion.

Dal-induced red blood cell incompatibilities in a Doberman Pinscher with von Willebrand factor deficiency and ehrlichiosis

OBJECTIVE

To describe a complex case involving the management of a dog with von Willebrand disease (vWD), active ehrlichiosis infection, nonregenerative anemia, and blood type incompatibility related to the Dal antigen.

CASE SUMMARY

A 13-week-oldintact male Doberman Pinscher weighing 7.2 kg was presented to the emergency service for a previous hemorrhaging event and progressive nonregenerative anemia. The dog had received a fresh whole blood transfusion 8 days prior to presentation due to severe anemia. Upon presentation, the puppy was tachycardic, and his mucous membranes were pale. A CBC revealed a nonregenerative anemia with a PCV of 0.11 L/L (11%). von Willebrand factor deficiency was suspected and later confirmed. The dog's blood type was dog erythrocyte antigen (DEA) 1 positive, but cross-matching to 4 RBC units, both DEA 1 positive and negative, failed to yield any compatible units. Antibody against a possible Dal RBC antigen was suspected, and 11 blood donors (Dalmatians and Dobermans) were cross-matched to find 2 compatible donors. After an uneventful fresh whole blood transfusion, a bone marrow biopsy revealed a hypocellular bone marrow and erythroid hypoplasia. A SNAP4DxPlus test and subsequent polymerase chain reaction (PCR) testing were positive for Ehrlichia ewingii and E. canis. Treatment with doxycycline was started, and the PCV was 0.17 L/L (17%) at discharge. At the 1-week follow-up, the PCV was 0.24 L/L (24%), and the puppy was doing well.

NEW OR UNIQUE INFORMATION PROVIDED

This is a unique case of a dog presenting with several challenging disorders, including vWD resulting in hemorrhage, ehrlichiosis potentially contributing to a nonregenerative anemia, and a blood type incompatibility due to the Dal antigen. Doberman Pinschers have a high prevalence of vWD- and Dal-negative phenotype, which emphasizes the value of cross-matching and the recognition of antigen prevalence in specific breeds.

Small Animal Transfusion Medicine

Transfusion medicine can be a lifesaving intervention. Component therapy has expanded the availability and blood products available. Patient safety and minimizing risk is important and can be accomplished through proper donor screening, collection, storage, compatibility testing, administration, and monitoring. The pros and cons of available products must be considered and tailored to each individual patient. Recent discoveries include new antigens and blood types, microbial effects on blood type, and the association between blood type and disease prevalence.

Survey of Blood Groups DEA 1, DEA 4, DEA 5, Dal, and Kai 1/Kai 2 in Different Canine Breeds From a Diagnostic Laboratory in Germany

More than twelve blood group systems have been described in dogs, but little is known about their distribution frequencies within breed populations. Here, we report on an extensive typing survey carried out using available reagents and either established or new clinical kits in purebred dogs from Germany. Leftover anticoagulated blood samples were examined using an immunochromatographic strip method for DEA 1, a gel column technique for Dal and Kai 1/2, and new card agglutination tests for DEA 4 and DEA 5 (which were partially compared with the gel column technique). Monoclonal antibodies were used for DEA 1 and Kai 1/2 typing, and polyclonal antibodies were used for all other types. Among the 206 dogs, 59.2% were DEA 1+, 100% DEA 4+, 9% (Card)/11% (Gel) DEA 5+, 89.3% Dal+, 96.6% Kai 1+, and 2.9% Kai 2+. None of the dogs were Kai 1+/2+, and only one was Kai 1-/2-. Dal- dogs were found in several breeds. Erythrocytes from most DEA 1+ dogs bound strongly on the strips. The agglutination reactions for DEA 5 on the new card tests were generally less than those on the gel column. The blood group pattern DEA 4+, DEA 5-, Dal+, Kai 1+/2- and either DEA 1+ or DEA 1- was found among 80% of the dogs. In this first extensive blood typing survey of purebred dogs from Europe, the proportions of positive and negative blood types were similar to those found in the United States and, for DEA 1, were also similar to those from other European countries, with considerable breed variation in blood types. The newer typing techniques seem to work well and will likely be useful for detecting and preventing specific blood type incompatibilities in the clinic.

Alloimmunization of a dog erythrocyte antigen 1- dog transfused with weakly dog erythrocyte antigen 1+ blood

BACKGROUND

Acute hemolytic transfusion reactions because of dog erythrocyte antigen (DEA) 1 sensitization after mismatched transfusions are serious complications. Dog erythrocyte antigen 1 expression varies from negative to weakly to strongly positive.

OBJECTIVES

To assess alloimmunization after transfusion of weakly DEA 1+ blood to a DEA 1- dog.

ANIMALS

One DEA 1- recipient and 1 weakly DEA 1+ donor, and 106 control dogs.

METHODS

Long-term follow-up study. Matched for DEA 3, 4, 5, and 7, Dal, and Kai 1 and 2, weakly DEA 1+ donor packed red blood cells (RBCs) were transfused 3 times (0.45 mL/kg at Day 0, 16, and 37) to a DEA 1- recipient. Alloantibodies against RBCs from donor and 106 controls were determined in recipient's plasma samples using a commercial antiglobulin-enhanced immunochromatographic strip and gel tube crossmatches. Alloantibody titers were determined.

RESULTS

The DEA 1- recipient was sensitized after 16 days to ≥1657 days after transfusion to weakly DEA 1+ and otherwise matched RBCs. Strong to moderate crossmatch incompatibilities were observed between recipient's plasma and all 61 DEA 1+ crossmatched controls. Moderate to weak incompatibilities were also observed to DEA 1- controls. Anti-DEA 1 and other alloantibodies were detected over the 4.5 year observation period.

CONCLUSIONS AND CLINICAL IMPORTANCE

Blood from a weakly DEA 1+ donor induces a strong and durable alloimmunization in a DEA 1- recipient dog. Additional alloantibodies developed against yet to be defined RBC antigens. Those results support the recommendation of typing dogs against DEA 1, considering weakly DEA 1+ as immunogenic, and crossmatching all previously transfused dogs.

Detection of naturally occurring alloantibody by an in-clinic antiglobulin-enhanced and standard crossmatch gel column test in non-transfused domestic shorthair cats

Background

Blood typing for the A and B antigens is essential and crossmatching testing is generally recommended before transfusing blood to cats.

Objective

To evaluate 2 crossmatch (XM) tests.

Animals

Forty‐nine healthy domestic shorthair cats that had not received a blood transfusion.

Methods

Prospective study. Blood samples were typed for AB using immunochromatographic and flow cytometric techniques. A gel column (GC) and a feline antiglobulin‐enhanced gel column (AGC) XM tests were used for crossmatching.

Results

The population included 34 type A, 13 B, and 2 AB cats, with concordant results (r = 1, P < .005) by flow cytometry and immunochromatographic strip kit. The plasma from type A cats had either no or weak anti‐B alloantibodies. The plasma of 12 of 13 type B cats contained strong anti‐A alloantibodies. For crossmatching, plasma to RBC pairings were prepared using the GC (n = 446) and AGC (n = 630) tests. Both methods showed compatibilities in 329 and incompatibilities in 102 pairings including all A‐B mismatches. Additionally 15 pairings showed agglutination by the AGC but not GC method. Fourteen incompatibilities outside the expected A‐B mismatches were only revealed by AGC.

Conclusions and Clinical Importance

AB typing using immunochromatographic strip is as accurate as laboratory flow cytometry. The 2 XM methods had good agreement with additional incompatibilities being recognized by the AGC XM beyond A‐B incompatibilities. In clinic, feline AB typing and sensitive XM test kits are available and recommended before each transfusion, although the clinical implications of incompatible XM test results and clinical benefits of such crossmatching have not been documented.

Comparison of cross-matching method for detection of DEA 7 blood incompatibility

We compared 3 major cross-match (XM) tests to identify dog erythrocyte antigen (DEA) 7 blood incompatibilities in dogs as a result of anti-DEA 7 antibodies: gel (GEL), standard tube (TUBE) agglutination, and immunochromatography strips (STRIP). Blood samples from 42 dogs were typed for DEA 7; 2 tested DEA 7-positive (DEA 7+). The 40 DEA 7-negative (DEA 7-) plasma samples were cross-matched against the 2 DEA 7+ and 3 DEA 7- red blood cell (RBC) samples by GEL to identify samples with anti-DEA 7 antibodies. Twenty DEA 7- plasma samples without and with anti-DEA 7 antibodies were cross-matched with samples of the 2 DEA 7+ RBCs in a double-blind fashion using the TUBE and STRIP XM methods. GEL results were used as the reference method for comparison. To determine relationships between results, 2 × 2 tables were used. Cohen kappa coefficient (κ) was calculated between results of GEL and the other 2 methods. With GEL, 21 of 40 XM tests were positive and 19 of 40 negative for anti-DEA 7 antibodies. The same results were obtained by TUBE, whereas only 1 of 40 XM tests was positive by STRIP. There was a statistically significant relationship between results of GEL and TUBE ( p < 0.000) with perfect agreement (κ = 1.000), but not between GEL and STRIP results ( p = 1.000) in which agreement was equivalent to chance (κ = 0.0453). The GEL and TUBE XM tests, but not STRIP, are useful methods for identification of DEA 7 incompatibilities caused by anti-DEA 7 antibodies.

Phenylephrine use for blood sparing during splenectomy in a dog

A dog with immune-mediated haemolytic anaemia was presented for splenectomy. Phenylephrine administration immediately before the removal of the spleen induced splenic contraction and significantly elevated packed cell volume. This technique conserved red blood cells and may be beneficial in euvolaemic animals to reduce the likelihood of a transfusion being required in the event of surgical haemorrhage.

Carbon Monoxide-Releasing Molecule Enhances Coagulation and Decreases Fibrinolysis in Normal Canine Plasma

The dog is an important companion animal and also purpose-bred for research studies. Coagulopathies in dogs are common, although the availability of blood products for therapy is inconsistent throughout the profession. A pro-coagulant therapeutic that is readily available and easily stored would be useful for the treatment of coagulopathies. Tricarbonyldichlororuthenium (II) dimer [Carbon monoxide-releasing molecule-2 (CORM-2)] acts as a prothrombotic agent in plasma by increasing the velocity of clot formation and clot strength, and by decreasing the clot's vulnerability to fibrinolysis. We sought to test CORM-2's effect on coagulation and fibrinolysis in vitro in canine plasma using thromboelastography. Measures of the rate of clot formation and clot strength in plasma without CORM-2 were highly correlated with fibrinogen concentration. We found that CORM-2 significantly enhanced the rate of clot formation and clot strength and significantly reduced the rate of fibrinolysis and the clot lysis time. The per cent change in rate of clot formation and clot strength was not significantly correlated with fibrinogen concentration, indicating that CORM-2's pro-coagulant effect is not dependent on fibrinogen concentration. This study corroborates studies in other species that show that CORM-2 is pro-coagulant in plasma, and lays the groundwork for developing CORM-2 as a therapeutic agent for canine coagulopathies. Future studies will evaluate the effect of CORM-2 on whole blood both in vitro and in vivo.