An 18-µm microaggregate blood filter does not cause hemolysis during in vitro whole blood transfusions in sea turtles

OBJECTIVE

Determine the hemolytic effect of an 18-µm microaggregate blood filter during in vitro sea turtle whole blood transfusions as well as describe the average diameter of leatherback (Dermochelys coriacea) and Kemp's ridley sea turtle (Lepidochelys kempii) RBCs.

ANIMALS

5 green (Chelonia mydas), 5 loggerhead (Caretta caretta), and 5 Kemp's ridley sea turtles (total n = 15).

METHODS

Heparinized sea turtle blood was infused at 60 mL/h through a microbore extension set without and then with a postsyringe, inline 18-µm microaggregate blood filter. Pre- and postfiltration PCV, Hct, total solids, sodium, chloride, potassium, glucose, and free plasma hemoglobin concentrations were measured. With the use of light microscopy and archived blood smears, the maximum and minimum diameter of 20 RBCs from each of the 5 leatherback and 5 Kemp's ridley sea turtles were measured with a calibrated ocular micrometer using 400X magnification.

RESULTS

There were no significant differences between pre- and postfiltration samples for Hct, total solids, sodium, chloride, potassium, glucose, and free plasma hemoglobin concentrations; however, there was a significant median postfiltration decrease in PCV of approximately 4%, representing a 13% decrease of the total RBCs transfused. Average maximum diameters for leatherback and Kemp's ridley sea turtle RBCs were 19.7 and 16.1 µm, respectively.

CLINICAL RELEVANCE

Although the 18-µm microaggregate blood filter does not hemolyze transfused sea turtle RBCs and is likely safe for in vivo blood transfusions, the filter's pores may retain a small proportion of infused RBCs given their diameter.

Effect of leukoreduction on the metabolism of equine packed red blood cells during refrigerated storage

BACKGROUND

Understanding of the biochemical and morphological lesions associated with storage of equine blood is limited.

OBJECTIVE

To demonstrate the temporal sequences of lipid and metabolic profiles of equine fresh and stored (up to 42 days) and leukoreduced packed red blood cells (LR-pRBC) and non-leukoreduced packed RBC (nLR-pRBC).

ANIMALS

Packed RBC units were obtained from 6 healthy blood donor horses enrolled in 2 blood banks.

METHODS

Observational study. Whole blood was collected from each donor using transfusion bags with a LR filter. Leukoreduction pRBC and nLR-pRBC units were obtained and stored at 4°C for up 42 days. Sterile weekly sampling was performed from each unit for analyses.

RESULTS

Red blood cells and supernatants progressively accumulated lactate products while high-energy phosphate compounds (adenosine triphosphate and 2,3-Diphosphoglycerate) declined. Hypoxanthine, xanthine, and free fatty acids accumulated in stored RBC and supernatants. These lesions were exacerbated in non-LR-pRBC.

CONCLUSION AND CLINICAL IMPORTANCE

Leukoreduction has a beneficial effect on RBC energy and redox metabolism of equine pRBC and the onset and severity of the metabolic storage lesions RBC.

Caprine whole blood appears sufficiently stable after 21 days in storage to be suitable for transfusion

OBJECTIVE

The objective of this study was to determine hematologic changes of stored caprine whole blood in citrate phosphate dextrose adenine solution over a 28-day period.

SAMPLE

Ten 250-mL bags of whole blood were collected from 10 female Boer goats from Louisiana State University's Division of Laboratory Animal Medicine herd.

METHODS

10 healthy blood donor goats were selected, and 250 mL of whole blood was drawn from each and stored at 2.78 °C. At the time of collection and every 7 days for a total of 28 days, samples were obtained from the blood bags to determine biochemical and hematologic values of collected blood. Only 5 of the 10 donors had baseline blood bag samples obtained for biochemical evaluation on day 0. At the end of 28 days, the remaining blood was submitted for aerobic and anaerobic culture.

RESULTS

Blood values remained within suitable limits for transfusion and below 1% hemolysis for up to 21 days in most samples. Packed cell volume did not change significantly from day 0 to day 28. Lactate significantly increased over the 28 days, though not as dramatically as expected on the basis of other blood storage studies. pH decreased due to anticoagulant acidity but did not drop below 7. Cultures were negative on all blood bags.

CLINICAL RELEVANCE

Changes over time are similar to that in other species, and caprine blood appears biochemically and hematologically stable for up to 21 days in storage. In vivo trials are needed for safety and efficacy.

Discordance between ABC blood phenotype and genotype in a domestic short-haired cat

An adult domestic short-haired feline leukemia virus-infected cat was referred for kidney failure and worsening anemia requiring transfusions. ABC blood typing was performed with an immunochromatographic strip assay at different occasions. Gel column systems were used for the major and minor crossmatching tests, and anti-A and anti-B titers were determined. No discrete A or B bands appeared on the immunochromatographic strips at any time point for the recipient cat. The recipient's plasma agglutinated RBCs from tested type A and B cats. The recipient's RBCs appeared compatible with plasma from 1 type A and 2 B donors, and incompatible with plasma from another type A cat. Genotyping of recipient blood revealed a single homozygous c.179G>T CMAH variant predicting a blood type B. These studies suggest an unusual weak type B or missing all ABC antigens. The latter resembles the exceedingly rare Bombay phenotype in the human ABO blood group system.

Human intravenous immunoglobulin use for hematological immune-mediated disease in dogs

OBJECTIVE

To report on survival rates and risk factors in dogs with immune-mediated hemolytic anemia (IMHA) and immune-mediated thrombocytopenia (ITP) treated with human IV immunoglobulin (hIVIG; Privigen). We hypothesized that hIVIG could be used as a salvage treatment to improve survival and reduce the requirement for ongoing blood transfusion therapy in IMHA and ITP patients.

ANIMALS

52 client-owned dogs with IMHA or ITP were included, comprising 31 females (28 spayed and 3 entire) and 21 males (19 castrated and 2 entire). Miniature Schnauzers were the most common breed (5), with a further 24 different breeds identified.

PROCEDURES

A retrospective cohort study was conducted between January 2006 and January 2022 that assessed the survival rates, risk factors, and need for ongoing transfusion in dogs with IMHA and ITP treated with hIVIG compared with those not receiving hIVIG.

RESULTS

Of 36 dogs that did not receive hIVIG, 29 (80%) survived and 7 (24%) died, and of 16 dogs administered hIVIG, 11 (69%) survived and 5 (31%) died (P = .56). No effect of PCV at admission or age on the risk of death was detected (OR, 1.00; 95% CI, 0.94 to 1.08; P = .89; and OR, 1.10; 95% CI, 0.85 to 1.47; P = .47, respectively).

CLINICAL RELEVANCE

This was the largest study to date of dogs with hematological immune-mediated disease treated with hIVIG. There was no difference in survival rates for dogs that received hIVIG versus those treated with standard immunosuppression. The benefit of hIVIG as a salvage treatment appears limited.

Retrospective study of canine blood xenotransfusion compared with type-matched feline blood allotransfusion to cats: indications, effectiveness, limitations and adverse effects

OBJECTIVES

Xenotransfusion is the transfusion of blood from one species to another. With varying availability of allogenic feline blood (AFB) and in emergency conditions, circumstances occur when canine blood is transfused to cats. This study aimed to characterise the indications, effectiveness, limitations, and acute and late transfusion-related adverse effects of canine blood xenotransfusion compared with matched AFB to anaemic cats, and their survival and longer-term outcome.

METHODS

This retrospective study (2013-2020) examined cats receiving canine blood xenotransfusions or AFB.

RESULTS

The study included 311 cats (xenotransfusion [X-group], n = 105; allotransfusion [A-group], n = 206). Xenotransfusion was more frequent among cats sustaining haemorrhage than in those with haemolysis (P <0.01) or hypoproliferative anaemia (P <0.001). Financial constraints were the most common reason to elect xenotransfusion (49%). The post-transfusion mean packed cell volume was higher (P <0.001) in the X-group (22%) compared with the A-group (18%), and also higher (P <0.001) at 48-96 h post-transfusion (23% vs 18%, respectively). Transfusion-related adverse effects (TRAEs) were more frequent (P = 0.001) in the X-group (37.1%) compared with the A-group (19.4%), as were delayed haemolytic transfusion reactions (85% vs 42.5%, respectively; P <0.001). Acute transfusion reactions (ATRs) were more frequent (P <0.001) in the A-group (60%) compared with the X-group (20%). TRAEs were unassociated with survival to discharge. The survival to discharge rate of the X-group (55%) was lower (P = 0.007) than in the A-group (73%), while post-discharge survival rates to 30 days of cats surviving to discharge were 90% and 88%, respectively (P = 0.85).

CONCLUSIONS AND RELEVANCE

Canine blood xenotransfusions to cats might save lives in emergency conditions when AFB is unavailable or blood typing is infeasible. The survival to discharge rate of the X-group was lower than that of the A-group. The longer-term survival rate of cats administered xenotransfusions and surviving to discharge from the hospital was good.

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.

Whole blood transfusion in common marmosets: a clinical evaluation

In veterinary medicine, blood transfusion is commonly performed on companion animals. The common marmoset is a small nonhuman primate with increasing popularity as an animal model in biomedical research. Because of its small whole blood volume, the marmoset is at high risk of exsanguination, and blood transfusion is required to care for life-threatening bleeding. However, few clinical evaluations exist on transfusions for marmosets. This study performed whole blood transfusion with cross-matching on nine marmosets and surveyed the therapeutic effects. Recipients included clinical cases with persistent bleeding, anemia, and coma, as well as animals subjected to postoperative bleeding prophylaxis. Donors were selected from healthy marmosets, including littermates. Cross-match assay before transfusion were all negative, and recipients showed no visible signs of transfusion-related adverse reactions. Whole blood transfusions caused hemostasis and successful recovery in bleeding marmosets, including long-term improvement of anemia cases. Our results indicated that blood transfusion is effective for marmosets with severe anemia and persistent hemorrhage from both non-experimental and surgical causes. Furthermore, DNA sequencing for blood-group classification revealed that all subject marmosets were type A, suggesting that the risk of blood type mismatch may be low in this species.

Effect of packed red blood cell transfusion on thromboelastographic tracings in dogs with naturally occurring anemia

OBJECTIVE

To assess the effect of packed RBC (pRBC) transfusion on thromboelastographic (TEG) tracings in dogs with naturally occurring anemia.

ANIMALS

22 clinically anemic dogs that received a pRBC transfusion.

PROCEDURES

For each dog, a blood sample was collected before and within 3 hours after completion of the pRBC transfusion for a CBC, nonactivated TEG analysis, and measurement of blood viscosity. Wilcoxon signed rank tests were used to compare CBC, viscosity, and TEG variables between pretransfusion and posttransfusion blood samples. Multivariable linear regression was used to assess the effects of pretransfusion-posttransfusion changes in Hct, WBC count, and platelet count on changes in TEG variables.

RESULTS

Median posttransfusion Hct (21%; range, 13% to 34%) was significantly greater than the median pretransfusion Hct (12.5%; range, 7% to 29%). Packed RBC transfusion was associated with a median increase in Hct of 6.2% (range, 1.2% to 13%). Maximum amplitude significantly decreased from 74.9 to 73.8 mm and clot strength significantly decreased from 14,906 to 14,119 dynes/s after pRBC transfusion. Blood viscosity significantly increased, whereas platelet and WBC counts significantly decreased after transfusion. Multivariable linear regression revealed that pretransfusion-posttransfusion changes in Hct, WBC count, and platelet count were not associated with changes in TEG variables.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that pRBC transfusion had only small effects on the TEG tracings of hemodynamically stable dogs. Therefore, large changes in TEG tracings following pRBC transfusion are unlikely to be the result of the transfusion and should be investigated further.

Management of a severe peripartum hemorrhage following cesarean section in a dog

This report describes the intensive blood pressure management and transfusion of a peripartum intrauterine hemorrhage following a cesarean section in a dog. The impact of pregnancy-associated physiologic changes and anesthesia on hemodynamic parameters along with potential alternate management techniques are discussed.

Assessment of erythrocyte damage and in-line pressure changes associated with simulated transfusion of canine blood through microaggregate filters

OBJECTIVE

To determine whether passage of whole blood through a microaggregate filter by use of a syringe pump would damage canine erythrocytes.

SAMPLE

Blood samples obtained from 8 healthy client-owned dogs.

PROCEDURES

Whole blood was passed through a standard microaggregate filter by use of a syringe pump at 3 standard administration rates (12.5, 25, and 50 mL/h). Prefilter and postfilter blood samples were collected at the beginning and end of a simulated transfusion. Variables measured at each time point included erythrocyte osmotic fragility, mean corpuscular fragility, RBC count, hemoglobin concentration, RBC distribution width, and RBC morphology. In-line pressure when blood passed through the microaggregate filter was measured continuously throughout the simulated transfusion. After the simulated transfusion was completed, filters were visually analyzed by use of scanning electron microscopy.

RESULTS

Regardless of administration rate, there was no significant difference in mean corpuscular fragility, RBC count, hemoglobin concentration, or RBC distribution width between prefilter and postfilter samples. Additionally, there were no differences in in-line pressure during the simulated transfusion among administration rates. Echinocytes were the erythrocyte morphological abnormality most commonly observed at the end of the transfusion at administration rates of 12.5 and 25 mL/h.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that regardless of the administration rate, the microaggregate filter did not alter fragility of canine RBCs, but may have altered the morphology. It appeared that the microaggregate filter would not contribute to substantial RBC damage for transfusions performed with a syringe pump.

Plasma transfusions in horses with typhlocolitis/colitis

The outcome of treatment of horses with plasma for typhlocolitis/colitis at the Ontario Veterinary College-Health Sciences Centre was evaluated. Horses with typhlocolitis/colitis that received a plasma transfusion had higher odds of dying than did non-transfused horses. The clinical usefulness of transfusing plasma to hospitalized hypoproteinemic horses is questioned.

In Vitro Compatibility of Canine and Human Blood: A Pilot Study

Military working dogs (MWDs) are force multipliers that are exposed to the same risks as their human counterparts on the battlefield. Hemostatic resuscitation using blood products is a cornerstone of damage control resuscitation protocols for both humans and dogs. Canine-specific blood products are in short supply in mature theaters due to logistic and regulatory concerns and are almost nonexistent in austere environments, whereas human blood products are readily available at most surgical facilities. The objective of this study was to evaluate the in vitro compatibility of human and canine blood by using standard crossmatching techniques with the canine blood acting as the recipient and the human blood acting as the donor. Blood samples were collected from 20 government-owned canines (GOCs) and 7 healthy human volunteers in addition to washed red blood cells (RBCs) from a commercial blood typing kit. Major and minor crossmatches were conducted as well as a protein denatured crossmatch. All samples in this study showed strong cross-reactivity, with the majority demonstrating profound hemolysis and a minority showing substantial agglutination. Based on the results of this study, transfusion of human blood to an MWD cannot be recommended at this time.

Prevalence of naturally occurring non-AB blood type incompatibilities in cats and influence of crossmatch on transfusion outcomes

BACKGROUND

Recognition of the feline red blood cell (RBC) antigen Mik and the presence of naturally occurring anti-Mik antibodies resulting in acute hemolytic transfusion reactions prompted the recommendation to perform a crossmatch before a cat's first RBC transfusion, but this guideline has not yet become a standard practice.

OBJECTIVE

To determine the prevalence of naturally occurring non-AB alloantibodies detectable by tube crossmatch, and to compare transfusion outcomes in cats with and without a crossmatch performed.

ANIMALS

Three hundred cats that received an RBC transfusion, with or without a major crossmatch performed.

METHODS

Retrospective study.

RESULTS

Major crossmatch incompatibilities were documented in 23 of 154 transfusion-naive cats (14.9%) and in 15 of 55 previously transfused cats (27%; P = 0.042). Type-specific packed RBCs (pRBCs) were administered to 167 and 82 cats with and without a crossmatch, respectively. Median volume of pRBCs administered during the first transfusion was 5.3 mL/kg (range, 2.4-18 mL/kg). Median change in PCV scaled to dose of pRBCs was +0.8%/mL/kg; administration of crossmatch-compatible pRBCs was not associated with a greater increase in PCV. Febrile transfusion reactions occurred more often in cats that received non-crossmatched (10.1%) compared to crossmatched (2.5%) pRBCs (P = 0.022). Seventy-six percent of cats that received pRBC transfusions survived to hospital discharge. A crossmatch was not associated with improved survival to discharge or at 30 or 60 days posttransfusion.

CONCLUSIONS AND CLINICAL IMPORTANCE

The prevalence of naturally occurring non-AB incompatibilities is sufficiently high to justify the recommendation to perform a crossmatch before all (including the first) RBC transfusions in cats.

Incidence of blood transfusion requirement and factors associated with transfusion following liver lobectomy in dogs and cats: 72 cases (2007-2015)

OBJECTIVE To determine the incidence of blood transfusion, mortality rate, and factors associated with transfusion in dogs and cats undergoing liver lobectomy. DESIGN Retrospective case series. ANIMALS 63 client-owned dogs and 9-client owned cats that underwent liver lobectomy at a specialty veterinary practice from August 2007 through June 2015. PROCEDURES Medical records were reviewed and data extracted regarding dog and cat signalment, hematologic test results before and after surgery, surgical method, number and identity of lobes removed, concurrent surgical procedures, hemoabdomen detected during surgery, incidence of blood transfusion, and survival to hospital discharge (for calculation of mortality rate). Variables were compared between patients that did and did not require transfusion. RESULTS 11 of 63 (17%) dogs and 4 of 9 cats required a blood transfusion. Mortality rate was 8% for dogs and 22% for cats. Pre- and postoperative PCV and plasma total solids concentration were significantly lower and mortality rate significantly higher in dogs requiring transfusion than in dogs not requiring transfusion. Postoperative PCV was significantly lower in cats requiring transfusion than in cats not requiring transfusion. No significant differences in any other variable were identified between dogs and cats requiring versus not requiring transfusion. CONCLUSIONS AND CLINICAL RELEVANCE Dogs and cats undergoing liver lobectomy had a high requirement for blood transfusion, and a higher requirement for transfusion should be anticipated in dogs with perioperative anemia and cats with postoperative anemia. Veterinarians performing liver lobectomies in dogs and cats should have blood products readily available.

Second-generation Anticoagulant Rodenticide Poisoning in a Captive Andean Condor (Vultur gryphus)

A 28-year-old female Andean condor (Vultur gryphus) housed in an outside exhibit at the National Aviary in Pittsburgh, PA, began showing signs of weakness. Toxicosis with an anticoagulant rodenticide was suspected because its mate had died 1 day earlier from possible brodifacoum poisoning. A rapid decline in the packed cell volume, despite vitamin K₁ treatment, necessitated a blood transfusion with blood from bald eagles (Haliaeetus leucocephalus) and Steller's sea eagles (Haliaeetus pelagicus). Supportive therapy after transfusion included vitamin K₁ (5 mg/kg IM q12h) as well as enrofloxacin, vitamin B complex, selenium and vitamin E, and subcutaneous fluids as needed. After a 39-day treatment period, a tapering dosage of vitamin K₁ was initiated, and treatment ended after 17 weeks. However, 2 weeks later, the bird suffered from a potential relapse. It was successfully treated with a repeat tapering vitamin K₁ regimen lasting a total of 4 months.

Titres of alloantibodies against A and B blood types in non-pedigree domestic cats in Turkey: Assessing the transfusion reaction risk

The severity of a transfusion reaction depends on alloantibody titres within the recipients' blood. Determination of an agglutination titre of naturally occurring alloantibody may help to assess the risk of transfusion reactions following an unmatched transfusion in a cat population. In this group of 312 cats 227 had blood type A, 78 had blood type B, and seven had type AB blood. All type B cats tested showed gross evidence of agglutinating anti-A antibody with plasma titres ranging from 2 to 256. Among the 227 type A domestic cats tested for plasma anti-B alloantibody titres, 70% had gross agglutination with titres ranging from 2 to 16, while 17.6% had microscopic agglutination. The remaining 12.4% of the type A cats were negative for both gross and microscopic agglutination. Based on agglutinating titres, the relative risk of a transfusion reaction when type A or AB blood was given to a type B cat was 6.4% with acute severe reaction, acute mild reactions in 85.9% and premature red cell destruction in 7.7%. On the other hand, transfusion of type AB blood or type B blood to type A cats carries a potential risk of acute mild transfusion reaction in 4.4% and premature red cell destruction in 83.3%. Transfusion of type A or B blood to type AB cats results in no apparent clinical transfusion reactions.

Survival of Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’ in blood of cats used for transfusions

Blood transfusions are commonly administered to cats; associated risks include the transmission of various infectious diseases including Mycoplasma haemofelis (Mhf) and ‘ Candidatus Mycoplasma haemominutum’ (Mhm). Blood transfusions in citrate-phosphate-dextrose-adenine (CPDA-1) solution are commonly administered immediately or stored for up to 1 month prior to administration. It is unknown whether Mhf or Mhm survive in this solution or temperature. The purpose of this study was to determine if Mhf or Mhm remain viable after storage in CPDA-1 for varying periods of time. The results provide evidence that transmission of hemoplasmas to naïve cats occurs after administration of infected feline blood that has been stored in CPDA-1 solution for 1 h (Mhf) and 1 week (Mhm). These findings support the recommendation that cats used as blood donors be screened for Mhf and Mhm infections by polymerase chain reaction (PCR) assay prior to use.

Xenotransfusion of anemic cats with blood compatibility issues: pre- and posttransfusion laboratory diagnostic and crossmatching studies

BACKGROUND

Finding compatible feline blood donors can be challenging. Canine blood has been occasionally used when compatible feline blood was not available in emergency situations.

OBJECTIVES

The study goals were to describe the effects of xenotransfusion in 2 anemic cats receiving canine blood because of discordant blood types and acute transfusion reaction, respectively, and to report in vitro heterotyping and crossmatching results between canine and feline blood samples.

MATERIAL AND METHODS

Blood samples from patients and other cats and dogs were typed, crossmatched, and assessed for alloantibodies using gel, card, and immunochromatographic strip techniques.

RESULTS

Cat 1 was found to have type AB blood. Cat 2, which experienced an acute transfusion reaction, had type A blood. Neither had detectable alloantibodies against feline RBC. Both cats transiently improved after transfusion with canine blood; however, acute intravascular hemolysis occurred and the PCV rapidly declined. Blood typing post xenotransfusion with DEA 1 strips revealed a positive control band that was absent in feline blood, thus allowing for the identification of transfused canine RBC. Longitudinal assessment revealed that canine RBC could no longer be detected 4 days after xenotransfusion. Major crossmatching (feline plasma with canine RBC) resulted in both positive and negative reactions, depending on the cat. Minor crossmatching results showed mostly incompatibility.

CONCLUSION

While both cats survived xenotransfusion, the positive control band on the DEA 1 strip revealed that transfused canine RBC were short-lived and intravascular hemolysis occurred. Crossmatch results between cats and dogs showed varied incompatibilities and may not predict transfusion reactions.

Use of endoscopic-assisted argon plasma coagulation for the treatment of colonic vascular ectasia (angiodysplasia) in an adult dog

CASE DESCRIPTION

A 10-year-old neutered male mixed-breed dog was evaluated for a 5-year history of intermittent hematochezia and chronic anemia that were unresponsive to medical treatment.

CLINICAL FINDINGS

Colonoscopy revealed multifocal areas of coalescing tortuous mucosal blood vessels throughout the colon and rectum. Colonic vascular ectasia (angiodysplasia) was diagnosed on the basis of the endoscopic appearance of the lesions.

TREATMENT AND OUTCOME

The dog failed to respond to traditional medical treatments for colonic vascular ectasia and required multiple plasma and blood transfusions. The dog received 4 endoscopic-assisted argon plasma coagulation treatments, which resulted in long-term resolution of gastrointestinal hemorrhage. Colonic perforation occurred during the third argon plasma coagulation treatment. The perforation was surgically repaired. The dog remained free from clinical signs of colonic vascular ectasia for > 1 year after the third argon plasma coagulation treatment and was euthanized because of clinical deterioration associated with progressive heart disease.

CLINICAL RELEVANCE

Endoscopic-assisted argon plasma coagulation treatment is a novel treatment for dogs with colonic vascular ectasia and provided long-term resolution of clinical signs for the dog of this report. In human patients, complications associated with endoscopic-assisted argon plasma coagulation treatment include colonic perforation, which also occurred in the dog of this report.

Blood transfusion in cats: ABCD guidelines for minimising risks of infectious iatrogenic complications

OVERVIEW

The availability of blood components has increased the number of indications for transfusing cats, and fresh whole blood is readily accessible to clinicians because it can be taken from in-house donor cats or 'volunteer' feline blood donors. A certain amount of risk remains to the recipient cat, as immediate or delayed adverse reactions can occur during or after transfusion, related to immunemediated mechanisms. This article, however, focuses on adverse events caused by infectious agents, which may originate either from contamination of blood following incorrect collection, storage or transfusion, or from transfusion of contaminated blood obtained from an infected donor.

PREVENTION OF BLOOD CONTAMINATION

In cats, blood cannot be collected through a closed system and, therefore, collection of donor blood requires a multi-step manipulation of syringes and other devices. It is crucial that each step of the procedure is performed under the strictest aseptic conditions and that bacterial contamination of blood bags is prevented, as bacterial endotoxins can cause an immediate febrile reaction or even fatal shock in the recipient cat.

PREVENTION OF DISEASE TRANSMISSION

With a view to preventing transmission of blood-borne infectious diseases, the American College of Veterinary Internal Medicine has adopted basic criteria for selecting pathogens to be tested for in donor pets. The worldwide core screening panel for donor cats includes feline leukaemia virus, feline immunodeficiency virus, Bartonella species and feline haemoplasma. The list should be adapted to the local epidemiological situation concerning other vector-borne feline infections. The most practical, rapid and inexpensive measure to reduce transfusion risk is to check the risk profile of donor cats on the basis of a written questionnaire. Blood transfusion can never, however, be considered entirely safe.

[Causes, diagnostics and course of disease in 194 cats with anemia]

Anemia is a common hematological alteration in cats. The objective of this study was to evaluate the frequency of different types of anemia and the course of disease in cats with a hematocrit (hct) < 0.26 l/l. In a period of 18 months 194 cats were included and assigned to different anemia groups based on history, physical examination and laboratory parameters. Most cats had acute blood loss anemia (BA; 75/194; 38.7%). Frequent causes were trauma (39/75), hematuria (13/75) and hemostatic disorders (9/75). Anemia of inflammatory and neoplastic disease (AID) occurred in 22.2% (43/194) and hemolytic anemia (HA) in 18% (35/194). Half of those were presumptively immune-mediated (IHA). Four cats were diagnosed with hemotropic mycoplasma infection. Rare causes of anemia included anemia of renal disease (ARD; 18/194; 9.3%) and intramedullary non-regenerative anemia (INR; 13/194; 6.7%). The latter either had retroviral infection (6/13) or neoplasia (6/13). In cats with HA and INR anemia was often severe and very severe (Hct < 0.14 l/l) and in cats with AID and ARD usually mild (Hct 0.20-0.25 l/l). Cats with BA had significantly lower total protein concentrations than those with INR (p = 0,001), HA, AID and CNE (p < 0,001) and those with HA most often had hyperbilirubinemia (21/27). Blood transfusions were primarily given to cats with BA (37/75) and HA (19/35), especially those with IHA (13/17). 69% of the patients survived the first 14 days after the anemia was detected for the first time. Cats with HA had the highest survival rate.

A retrospective analysis of 25% human serum albumin supplementation in hypoalbuminemic dogs with septic peritonitis

This study describes the influence of 25% human serum albumin (HSA) supplementation on serum albumin level, total protein (TP), colloid osmotic pressure (COP), hospital stay, and survival in dogs with septic peritonitis. Records of 39 dogs with septic peritonitis were evaluated. In the HSA group, initial and post-transfusion TP, albumin, COP, and HSA dose were recorded. In the non-supplemented group, repeated values of TP, albumin, and COP were recorded over their hospitalization. Eighteen dogs survived (53.8% mortality). Repeat albumin values were higher in survivors (mean 23.9 g/L) and elevated repeat albumin values were associated with HSA supplementation. Repeat albumin and TP were higher in the HSA supplemented group (mean 24 g/L and 51.9 g/L, respectively) and their COP increased by 5.8 mmHg. Length of hospitalization was not affected. Twenty-five percent HSA increases albumin, TP, and COP in canine patients with septic peritonitis. Higher postoperative albumin levels are associated with survival.

Transmission of Chagas disease via blood transfusions in 2 immunosuppressed pigtailed macaques (Macaca nemestrina)

A 2.25-y-old male pigtailed macaque (Macaca nemestrina) was experimentally irradiated and received a bone marrow transplant. After transplantation and engraftment, the macaque had unexpected recurring pancytopenia and dependent edema of the prepuce, scrotum, and legs. The diagnostic work-up included a blood smear, which revealed a trypomastigote consistent with Trypanosoma cruzi, the causative agent of Chagas disease (CD). We initially hypothesized that the macaque had acquired the infection when it lived in Georgia. However, because the animal had received multiple blood transfusions, all blood donors were screened for CD. One male pigtailed macaque blood donor, which was previously housed in Louisiana, was positive for T. cruzi antibodies via serology. Due to the low prevalence of infection in Georgia, the blood transfusion was hypothesized to be the source of T. cruzi infection. The transfusion was confirmed as the mechanism of transmission when screening of archived serum revealed seroconversion after blood transfusion from the seropositive blood donor. The macaque made a full clinical recovery, and further follow-up including thoracic radiography, echocardiography, and gross necropsy did not show any abnormalities associated with CD. Other animals that received blood transfusions from the positive blood donor were tested, and one additional pigtailed macaque on the same research protocol was positive for T. cruzi. Although CD has been reported to occur in many nonhuman primate species, especially pigtailed macaques, the transmission of CD via blood transfusion in nonhuman primates has not been reported previously.

Iron deficiency anemia

Iron is essential to virtually all living organisms and is integral to multiple metabolic functions. The most important function is oxygen transport in hemoglobin. Iron deficiency anemia in dogs and cats is usually caused by chronic blood loss and can be discovered incidentally as animals may have adapted to the anemia. Severe iron deficiency is characterized by a microcytic, hypochromic, potentially severe anemia with a variable regenerative response. Iron metabolism and homeostasis will be reviewed, followed by a discussion of diagnostic testing and therapeutic recommendations for dogs and cats with iron deficiency anemia.

Alloimmune neonatal neutropenia and neonatal isoerythrolysis in a Thoroughbred colt

A 3-day-old Thoroughbred colt was originally presented for treatment of neonatal isoerythrolysis, which was treated with a blood transfusion. However, persistent neutropenia was observed despite the absence of detectable infection. Subsequently, a granulocyte agglutination test was performed by incubating the colt's neutrophils with the mare's serum; results were positive, leading to a clinical diagnosis of alloimmune neonatal neutropenia. The diagnosis was further supported via flow cytometric analysis. The colt was hospitalized and treated prophylactically with antimicrobials and 4 separate doses of recombinant human granulocyte colony-stimulating factor (rhG-CSF; 1.4-3.5 µg/kg, subcutaneously) in attempts to maintain the neutrophil count within reference intervals over a 4-week period. The colt's neutrophil count increased after administration of rhG-CSF and eventually stabilized within reference intervals by day 20. The colt maintained normal neutrophil counts after discharge and was reportedly healthy at 6 months of age. Alloimmune neonatal neutropenia should be considered in foals with persistent neutropenia in the absence of infection. Alloimmune neonatal neutropenia can be treated with prophylactic antimicrobials combined with rhG-CSF with a favorable outcome.

Plasma therapy in foals and adult horses

Although a range of plasma-based products (e.g., cryoprecipitate, albumin, platelet-rich plasma, individual coagulation factors) are available to human physicians, equine veterinarians are largely restricted to using whole blood, frozen plasma, and fresh frozen plasma for transfusions. The indications for frozen or fresh frozen plasma in human medicine are relatively limited, and there is little evidence supporting the efficacy of these products in many cases. Furthermore, many human physicians have concerns regarding disease transmission and anaphylactic reactions after administration of any plasma product. In equine medicine, plasma products have been used (1) to treat failure of passive transfer (FPT); sepsis; and coagulopathies; (2) as "antiendotoxin" agents; and (3) to provide colloidal support. The use of plasma should be carefully considered before administration because of potential (although rare) adverse reactions as well as expense. In addition, the benefits are uncertain in some equine patients.

Presumptive bovine neonatal pancytopenia in a Holstein calf in Québec

An 18-day-old heifer was presented with fever, depression, tachycardia, tachypnea, and prolonged bleeding time. Blood tests revealed severe anemia, thrombocytopenia, and leucopenia. The animal was negative by PCR for bovine virus diarrhea virus antigen. The findings supported a diagnosis of bovine neonatal pancytopenia. Treatments included fresh whole blood transfusion and antibiotics. The animal recovered fully.

Successful therapy of coumatetralyl rodenticide induced pericardial effusion with pericardiocentesis in a dog

A 5-year-old, intact male, golden retriever was presented with an acute onset of lethargy and respiratory distress. The dog was diagnosed as having rodenticide intoxication with pericardial effusion. Pericardiocentesis was successfully performed and was followed with a blood transfusion. This case suggests that rodenticide intoxication might cause pericardial effusion in dogs.

Avian transfusion medicine

Anemia is defined as a decreased capacity of the blood to carry oxygen and is recognized by packed cell volume, erythrocyte, and hemoglobin values below reference ranges. Causes of anemia in birds include blood loss, heavy metal toxicosis, parasitic infection, and chronic disease. Several differences exist between avian and mammalian physiology, including the avian ability to tolerate greater losses of blood. However, the use of blood products has become an effective tool for treating anemic avian patients. Whole blood transfusions (autologous, homologous, and heterologous) and administration of hemoglobin-based, oxygen-carrying solutions are the treatments used most commonly in birds.

Estrogen-induced myelotoxicity in dogs: A review

Exogenous estrogens used for therapeutic purposes or endogenous estrogen sources such as functional Sertoli cell or ovarian granulosa cell tumors may cause bone marrow toxicity in dogs. The condition is characterized by hematologic abnormalities including thrombocytopenia, anemia, and leukocytosis or leukopenia. Despite intensive therapy with blood or platelet-rich transfusions, broad-spectrum antibiotics, steroids, and bone marrow stimulants, prognosis is unfavorable. Due to the the risk of stimulating the development of uterine diseases and the potential for inducing aplastic anemia, estrogen use in dogs is best avoided where possible. This paper describes the causes of estrogen-induced myelotoxicity, the clinical presentation of the patients, the diagnosis, and the treatment options in the dog.

Effect of blood transfusion in combination with Dextran-40 and hypertonic saline solution on cardiopulmonary haemodynamics of endotoxin (lipopolysaccharide) shock in buffalo calves

The intravenous (i.v.) infusion of lipopolysaccharide (LPS) of E. coli endotoxin in buffalo calves (n = 15) at 5 microg/kg bw per h for 3 h caused a significant (p<0.05) fall in plasma volume, blood volume, haematocrit haemoglobin, and systolic, diastolic and pulse pressure, mean arterial pressure and central venous pressure (CVP), with a marked rise in respiration. Treatment with a combination of i.v. infusion of 7.2% hypertonic saline solution, Plasmex-D-40 (Dextran-40) and blood successfully alleviated hypovolaemia, and raised systolic, diastolic and pulse pressure, mean arterial pressure and central venous pressure. The whole blood was collected from apparently healthy male buffalo calves 24 h prior to infusion and was transfused without cross-matching. No significant fall in haemoglobin, haematocrit and body temperature was observed after transfusion. All these values tended to remain near normal levels. However, this combination of treatment had no effect on high respiratory rate. A one-time blood transfusion did not evoke any cross-reaction and was helpful in raising haematocrit and haemoglobin close to pre-infusion values. The general symptoms of restlessness, respiratory distress, profuse salivation, violent movement of the ears, snoring, intermittent struggle, etc. were markedly reduced. All the treated animals became quiet and lay with eyes open and survived the 7 h of observation.

Feline nonregenerative anemia: diagnosis and treatment

Anemia in cats is not a diagnosis but rather a sign of an underlying disease. The diagnostic work-up for an anemic patient is often extensive, starting with classification of the anemia as regenerative or nonregenerative. Once nonregenerative anemia is diagnosed, a number of tests may be required to determine its cause, including a close examination of the patient's blood and bone marrow. Although there are standard supportive measures for anemic cats, specific therapies can be implemented for certain etiologies of nonregenerative anemia.

Prion diseases are efficiently transmitted by blood transfusion in sheep

The emergence of variant Creutzfeld-Jakob disease, following on from the bovine spongiform encephalopathy (BSE) epidemic, led to concerns about the potential risk of iatrogenic transmission of disease by blood transfusion and the introduction of costly control measures to protect blood supplies. We previously reported preliminary data demonstrating the transmission of BSE and natural scrapie by blood transfusion in sheep. The final results of this experiment, reported here, give unexpectedly high transmission rates by transfusion of 36% for BSE and 43% for scrapie. A proportion of BSE-infected transfusion recipients (3 of 8) survived for up to 7 years without showing clinical signs of disease. The majority of transmissions resulted from blood collected from donors at more than 50% of the estimated incubation period. The high transmission rates and relatively short and consistent incubation periods in clinically positive recipients suggest that infectivity titers in blood were substantial and/or that blood transfusion is an efficient method of transmission. This experiment has established the value of using sheep as a model for studying transmission of variant Creutzfeld-Jakob disease by blood products in humans.

Clinical and clinicopathologic variables in adult horses receiving blood transfusions: 31 cases (1999–2005)

OBJECTIVE

To determine clinical and clinicopathologic abnormalities in horses administered a blood transfusion and evaluate effects of blood transfusion on these variables.

DESIGN

Retrospective case series.

ANIMALS

31 adult horses that received > or = 1 blood transfusion. Procedures-Medical records of horses receiving a blood transfusion were reviewed to obtain clinical findings, laboratory test results before and after transfusion, adjunctive treatments, transfusion type and volume, response to transfusion, results of donor-recipient compatibility testing, adverse reactions, and outcome.

RESULTS

31 horses received 44 transfusions for hemorrhagic anemia (HG; n = 18 horses), hemolytic anemia (HL; 8), or anemia attributable to erythropoietic failure (EF; 5). Tachycardia and tachypnea were detected in 31 of 31 (100%) and 22 of 31 (71%) horses, respectively, before transfusion. The PCV and hemoglobin concentration were less than the reference range in 11 of 18 horses with HG, 8 of 8 horses with HL, and 5 of 5 horses with EF. Hyperlactatemia was detected in 16 of 17 recorded values before transfusion. Heart rate, respiratory rate, and PCV improved after transfusion, with differences among the types of anemia. Seventeen (54%) horses were discharged, 9 (29%) were euthanized, and 5 (16%) died of natural causes. Adverse reactions were evident during 7 of 44 (16%) transfusions, varying from urticarial reactions to anaphylactic shock.

CONCLUSIONS AND CLINICAL RELEVANCE

Abnormalities in clinical and clinicopathologic variables differed depending on the type of anemia. Colic, cold extremities, signs of depression, lethargy, tachycardia, tachypnea, low PCV, low hemoglobin concentration, and hyperlactatemia were commonly detected before transfusion and resolved after transfusion.

Canine immune-mediated hemolytic anemia: treatment and prognosis

The treatment of primary immune-mediated hemolytic anemia involves short-term oxygen-carrying support and long-term immunosuppressive therapy. Therapeutic options include blood transfusion, standard and more speculative immunosuppressive agents, splenectomy, and prevention of thromboembolic disease. This article also discusses the prognosis and prognostic indicators.

Frequencies of blood type A, B and AB in non-pedigree domestic cats in Turkey

OBJECTIVES

To determine the distribution of blood types and to estimate the proportion of matings at risk for neonatal isoerythrolysis in non-pedigree domestic cats.

METHODS

The present survey determined the frequency of blood types in 301 cats from four distinct regions of Turkey. Ethylenediaminetetraacetic acid-anticoagulated blood samples were typed by simple tube and slide agglutination assays. Serum obtained from type B cats and an anti-B solution, prepared with Triticum vulgaris, were used to determine type A and type B blood, respectively.

RESULTS

Of the 301 cats typed, 220 had type A blood, 74 had type B and seven had type AB. There was a significant difference (P<0.01) between the locations of the cats, with fewer type B cats in the eastern than in the western parts of Turkey. Risk for the development of neonatal isoerythrolysis due to A-B mismatch was estimated to be 18.6 per cent.

CLINICAL SIGNIFICANCE

The overall type B frequency in Turkish domestic cats is high. Thus, untyped transfusions in these cats carry a high risk of life-threatening acute haemolytic transfusion reactions and neonatal isoerythrolysis. It is therefore strongly recommended that blood typing be performed before breeding or transfusing in order to minimise blood type incompatibility risks.

Hemophilia B in a crossbred Maltese dog

A crossbred Maltese dog, 6-year-old, male, was presented to us for examination due to coagulopathy. On examination of blood coagulation screening tests, activated partial thromboplastin time (APTT) was markedly prolonged (63.6 sec). Therefore, a defect in the intrinsic pathway of coagulation was suspected. An additional serum test was also examined and APTT was returned to within the normal range. Furthermore, factor IX coagulation activity was markedly low (2.3%). On the basis of these results, the dog was diagnosed with hemophilia B. The dog has since been presented to us because of hemorrhage problems again after 5, 10, and 16 months, but blood transfusions have maintained good control of its coagulopathy for more than two years.

Disseminated intravascular coagulation in cats

The purpose of this study was to describe the clinical characteristics of cats with disseminated intravascular coagulation (DIC), including associated diseases and hemostatic abnormalities, and to identify risk factors for death and treatments that potentially altered outcome. Medical records for cats with DIC from 1990-2004 were evaluated retrospectively. Inclusion criteria were the presence of an underlying disorder associated with DIC and either postmortem examination findings of intravascular fibrin deposition or thrombosis, or both of 2 or more organs or coagulation profiles that meet 3 of 5 criteria: prolonged prothrombin time (PT), activated partial thromboplastin time (aPTT), presence of fibrin degradation products (FDP), low plasma fibrinogen (FIB) concentration, and thrombocytopenia (<160,000 platelets/microL). Signalment, historical data, clinical findings, clinicopathologic data, underlying disorders, management, and outcome were recorded. Forty-six cats fulfilled the criteria for DIC. Cats ranged in age from 7 weeks to 17 years (median, 9 years). Hemorrhage was noted in 7 of 46 cats (15%). Three of 46 cats (7%) survived, whereas 43 of 46 (93%) died or were euthanized. The most common underlying disorders were lymphoma, other forms of neoplasia, pancreatitis, and sepsis. There was no association detected between outcome and signalment; underlying disease; hemorrhage; abnormalities in aPTT, FIB, FDPs, platelet count; transfusion of blood products; and heparin therapy. However, the median PT of nonsurvivors was more prolonged than in survivors (P < .005). DIC in cats can result from a variety of neoplastic, infectious, and inflammatory disorders, and is associated with a high case fatality rate.

Acute hepatic failure and coagulopathy associated with xylitol ingestion in eight dogs

CASE DESCRIPTION

8 adult dogs were evaluated for treatment of lethargy and vomiting after ingestion of xylitol, a sugar alcohol used as a sweetener in various products.

CLINICAL FINDINGS

In addition to vomiting and lethargy, 5 of the dogs had widespread petechial, ecchymotic, or gastrointestinal tract hemorrhages. Common clinicopathologic findings included moderately to severely high serum activities of liver enzymes, hyperbilirubinemia, hypoglycemia, hyperphosphatemia, prolonged clotting times, and thrombocytopenia. Necropsies were performed on 3 dogs and severe hepatic necrosis was found in 2. In the third dog, histologic examination revealed severe hepatocyte loss or atrophy with lobular collapse.

TREATMENT AND OUTCOME

Treatments varied among dogs and included IV administration of fluids; plasma transfusions; and, if indicated, administration of dextrose. Three dogs were euthanatized, 2 dogs died, 2 dogs made a complete recovery, and 1 dog was recovering but was lost to follow-up.

CLINICAL RELEVANCE

Although xylitol causes hypoglycemia in dogs, hepatic failure after ingestion has not previously been reported. Because an increasing number of consumer products contain xylitol, clinicians should be aware that ingestion of xylitol can have serious, life-threatening effects.

Congenital vulvar deformity in 6 alpacas

CASE DESCRIPTION

6 female alpacas, ranging in age from < 1 day to > 2 years, were examined because of primary owner complaints related to urogenital malformation.

CLINICAL FINDINGS

In all instances, the vulva was totally to subtotally imperforate. One neonate had failure of passive transfer of immunity and mild azotemia at the time of initial examination. No additional urogenital malformations were detected in any of the alpacas.

TREATMENT AND OUTCOME

Vulvoplasty performed via local anesthesia was successful in all alpacas. The neonate with failure of passive transfer received a plasma transfusion. Postsurgical wound management was limited to topically applied medications.

CLINICAL RELEVANCE

Congenital vulvar deformity in alpacas may result in interference with urine outflow. Neonates with a completely imperforate vulva may be brought to veterinarians for examination on an emergency basis. Less severely affected alpacas may be examined later in life with owner complaints ranging from stranguria or dysuria to urogenital malformation. No other primary abnormalities of the urogenital tract in alpacas have been reported, to the authors' knowledge. Vulvoplasty, performed with local anesthesia, resolves obstructed urine flow. Because it is possible that this condition is heritable, affected alpacas, and possibly their sires and dams, should not be used for breeding.