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.

Production and characterization of a murine anti-dal monoclonal antibody for blood typing in dogs.

Considering the strong immunogenicity of the Dal antigen, and that > 98% of dogs, including blood donors, are Dal-positive, finding compatible blood for a previously transfused Dal-negative patient may be challenging. This is exacerbated by limited access to typing reagents, which currently rely on polyclonal antibodies (PAb) produced following sensitization of dogs. Therefore, the objective of this study was to produce and characterize an anti-Dal murine monoclonal antibody (MAb). Conventional hybridoma technology was used to produce MAb directed against canine red blood cells (cRBC). Briefly, female BALB/c mice were immunized via repeated intraperitoneal injections of washed Dal-positive cRBC (DEA 1,3,7 negative; DEA 4,5 positive) until serologic titers were sufficient (>1:1000). Following fusion with myeloma cells, 573 hybridoma cell culture supernatants were obtained and screened for MAb of interest using a gel column agglutination technique and known Dal-negative and Dal-positive cRBC. Fifteen supernatants led to cRBC agglutination, but only one had the desired pattern (i.e. anti-Dal). To assess its specificity and sensitivity, Dal blood typing of 62 canine EDTA-blood samples was performed using the anti-Dal MAb and two canine PAb: 45 Dal-positive and 17 Dal-negative were identified with 100% agreement between reagents (kappa =1). The anti-Dal MAb produced was further determined to be an IgG1. Conventional hybridoma technology, aided by a gel column technique, has enabled the production of a murine MAb specific against the canine Dal antigen. This will ensure long-term perennity of Dal blood typing, facilitate clinical management and research, as well as avoid resorting to repeat dog sensitization.

Characterization of post-transfusion anti-FEA 1 alloantibodies in transfusion-naive FEA 1-negative cats.

OBJECTIVES: The aim of this study was to characterize anti-feline erythrocyte antigen (FEA) 1 alloantibodies following sensitization of FEA 1-negative cats, including their rate of appearance, agglutination titer over time and immunoglobulin class. A secondary aim was to obtain polyclonal anti-FEA 1 alloantibodies to increase the availability of FEA 1 blood typing. We also describe a case study documenting an acute hemolytic transfusion reaction in a transfusion-naive FEA 1-negative feline patient that received FEA 1-positive blood. METHODS: In this prospective clinical study, 35 cats with blood group type A underwent extensive blood typing for FEA 1-5. Two cats were identified as FEA 1-negative; these cats were transfused uneventfully with 50 ml of FEA 1-positive, but otherwise compatible, packed red blood cells. Post-transfusion blood samples were collected routinely as long as anti-FEA 1 alloantibodies were detected. Appearance of anti-FEA 1 alloantibodies was detected using a gel column crossmatch method. RESULTS: Anti-FEA 1 alloantibodies were detected as early as 5 days post-transfusion and remained detectable for over 400 days in one cat. Agglutination titers in both cats were relatively weak (1:1 to 1:8). The main immunoglobulin class was IgM. CONCLUSIONS AND RELEVANCE: Transfusion of FEA 1-negative, transfusion-naive cats with FEA 1-positive blood results in production of post-transfusion anti-FEA 1 alloantibodies as early as 5 days post-transfusion. Our results confirm the potential immunogenicity of FEA 1 and support crossmatching prior to a blood transfusion, even in transfusion-naive cats. Further studies are needed to better document the clinical importance of these post-transfusion antibodies, as well as to facilitate routine blood typing for the FEA 1 antigen in cats.

2021 ISFM Consensus Guidelines on the Collection and Administration of Blood and Blood Products in Cats.

PRACTICAL RELEVANCE: Blood and blood products are increasingly available for practitioners to use in the management of haematological conditions, and can be lifesaving and therapeutically useful for patients with anaemia and/or coagulopathies. It is important for feline healthcare that donors are selected appropriately, and transfusions of blood or blood products are given to recipients that will benefit from them. Complications can occur, but can be largely avoided with careful donor management and recipient selection, understanding of blood type compatibility, and transfusion monitoring. CLINICAL CHALLENGES: Feline blood transfusion, while potentially a lifesaving procedure, can also be detrimental to donor and recipient without precautions. Cats have naturally occurring alloantibodies to red cell antigens and severe reactions can occur with type-mismatched transfusions. Blood transfusions can also transmit infectious agents to the recipient, so donor testing is essential. Finally, donors must be in good health, and sedated as appropriate, with blood collected in a safe and sterile fashion to optimise the benefit to recipients. Transfusion reactions are possible and can be mild to severe in nature. Autologous blood transfusions and xenotransfusions may be considered in certain situations. EVIDENCE BASE: These Guidelines have been created by a panel of authors convened by the International Society of Feline Medicine (ISFM), based on available literature. They are aimed at general practitioners to provide a practical guide to blood typing, cross-matching, and blood collection and administration.

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.

Xenotransfusion of canine blood to cats: a review of 49 cases and their outcome.

OBJECTIVES: To describe the use of a xenotransfusion protocol, the outcome of xenotransfusion in recipient cats and to assess owner memory of the xenotransfusion. MATERIALS AND METHODS: Cats administered xenotransfusions in two hospitals between January 2016 and July 2018 were included. Adherence to xenotransfusion protocol, cause of anaemia, blood type, packed cell volume (PCV), transfusion volume, transfusion reactions, PCV 12 hours after transfusion and survival to discharge were recorded. Owners of surviving cats were questioned to assess if they remembered that a xenotransfusion had been performed. RESULTS: Forty-nine cats underwent the xenotransfusion protocol. The most common causes of anaemia were surgical blood loss (n = 17), immune-mediated haemolytic anaemia (n = 14) and neoplasia (n = 14). Median PCV before transfusion was 10%. Six cats (12%) had febrile non-haemolytic transfusion reactions. Median PCV 12 hours after transfusion was 25%. Ten cats (20%) died or were euthanased within 24 hours of xenotransfusion. A delayed haemolytic transfusion reaction occurred in 25 of 39 (64%) cats manifesting as icterus in 15 cats after a median of 1.9 days and haemolytic serum in 19 cats after a median of 2 days. Of the 18 cats alive at 1 week after discharge, 15 (83%) were still alive at a median of 173 days after xenotransfusion. All owners contacted remembered that their cats had received a xenotransfusion. CLINICAL SIGNIFICANCE: Xenotransfusion of canine packed red blood cells to cats is possible but haemolysis should be expected between 1 and 6 days after transfusion.

The degree of major histocompatibility complex matching between purebred Maltese and mongrel dogs using microsatellite markers.

Long-term maintenance of transplanted organs is one of the major factors that increases survival time of recipients. Although obtaining a major histocompatibility complex (MHC)-matched donor with the recipient is essential for successful organ transplantation, there have been limited reports on MHC matching between dogs. In this study, we analyzed the canine MHC matching rates using Maltese, one of the most popular purebred dogs, and mongrel dogs in Korea. Genomic DNA was extracted from blood leukocytes and DNA was amplified by polymerase chain reaction with primers specific to MHC microsatellite markers. The MHC matching degree was confirmed by the microsatellite markers using polyacrylamide gel electrophoresis. The MHC matching rates of each donor-recipient groups including Maltese-Maltese, mongrel-mongrel and Maltese-mongrel were 4.76%, 5.13% and 6.67%, respectively. There were no significant differences in the MHC matching degree between each group. These results demonstrate that MHC-matched donors could be selected from other breeds as much as from the same breed for transplantation. Knowledge of the MHC matching degree of purebred and mongrel dogs would offer valuable information not only for improving the success rate of organ transplantation surgery in canine patients but also for transplantation research using experimental canine models.

DEA 1. 1 blood group frequency in dogs attended at the veterinary hospital of UFMT (Sinop/MT), risk of DEA 1 negative dog sensitization and occurrence of hemolytic transfusion reaction in a second blood transfusion / Frequência do grupo sanguíneo DEA 1. 1 em cães atendidos no Hospital Veterinário da UFMT (Sinop/MT), risco de sensibilização de cães DEA 1 negativos e da ocorrência de reação transfusional hemolítica por ocasião de uma segunda transfusão de sangue

The goal of this research was to identify the frequency of the DEA 1.1 blood group in dogs from Sinop, Mato Grosso, Brazil, to help in the recruitment of compatible blood donors and recipients, and to assess the risk of transfusion reactions in previously sensitized dogs. Also, from the obtained results, to pick potential blood donors to compose a data bank. 195 adult dogs (1 to 4 years old), males and females, mongrel and purebred dogs were screened at the Veterinary Hospital of the University of Mato Grosso. The DEA 1.1 blood typing was performed using commercially available immunochromatographic strip for DEA 1.1 (Quick Test DEA 1.1, Alvedia, Lyon, France). The results showed a general frequency of 65% for DEA 1.1 positive dogs (n = 126) and 35% for DEA 1 negative dogs (n = 69). The general risk of sensitization of a DEA 1 negative dog following a first transfusion with DEA 1.1 positive blood was 23%, while the risk of this sensitized recipient to receive DEA 1.1 positive blood in a second transfusion and to develop an acute hemolytic reaction was calculated to be 5%. The blood typing of the dogs allowed their classification as DEA 1 typed blood donors, in a preliminary data bank, and also ensured the safety of blood transfusions.

Objetivou-se identificar a frequência do grupo sanguíneo DEA 1.1 em cães de Sinop, Mato Grosso, Brasil, para auxiliar a seleção de doadores e receptores de sangue compatíveis e, adicionalmente, avaliar o risco de reações transfusionais em cães sensibilizados. Além disso, a partir dos resultados obtidos, selecionar potenciais doadores de sangue para compor um banco de dados. Um total de 195 cães adultos (de 1 a 4 anos de idade), machos e fêmeas, mestiços e puros, que nunca haviam recebido transfusões de sangue, foram triados no Hospital Veterinário da Universidade do Mato Grosso. A tipagem sanguínea DEA 1.1 foi realizada utilizando-se ensaio imunocromatográfico comercialmente disponível para DEA 1.1 (Quick Test DEA 1.1, Alvedia, Lyon, França). Os resultados demonstraram uma frequência geral de 65% para cães DEA 1.1 positivos (n = 126) e 35% para cães DEA 1 negativos (n = 69). O risco geral de sensibilização de cães DEA 1 negativos após uma primeira transfusão com sangue DEA 1.1 positivo foi calculado em 23%, enquanto o risco deste receptor sensibilizado receber sangue DEA 1.1 positivo em uma segunda transfusão e desenvolver uma reação hemolítica aguda foi calculado em 5%. A tipagem sanguínea dos cães permitiu sua inserção como doadores de sangue tipados para o grupo DEA 1 em um banco de dados preliminar e garantiu a segurança das transfusões de sangue.

Helicobacter spp. in domestic cats: identification and relationship with anatomical and histopathological gastric changes in animals of blood group A / Helicobacter spp. em gatos domésticos: identificação e relação com alterações gástricas anatômicas e histopatológicas em animais de sangue tipo A

The aim of this study was to evaluate the presence of gastric Helicobacter-like organisms and the endoscopic and histopathological changes in domestic cats with blood type A. Samples from the stomach antrum, body and fundus were collected from 32 mixed-breed stray domestic cats using gastroscopy. Urease testing and cytological analysis were performed in fresh samples. Tissue sections were processed and stained with hematoxylin and eosin (H&E) and the Warthin-Starry (WS) silver staining methods for histopathological examination. Helicobacter spp. were detected in 100% of samples subjected to silver staining and cytological analysis, and in 96.9% of samples subjected to urease testing. In 87.5% of the cats, mononuclear inflammatory-cell infiltrates were identified. The graduation and distribution of inflammatory infiltrates in these cats revealed mild (78.1%) to moderate (9.4%) inflammatory changes in at least one gastric region. These changes were independent of the colonization score. Hyperplasia of the lymphoid follicles was detected in three cats. Cats of blood group A are often colonized by Helicobacter spp. and the macroscopic and microscopic findings are consistent with studies in domestic cats reported to date, concluding that the most common blood group in cats is not associated with high susceptibility to symptomatic gastritis.(AU)

O objetivo deste estudo foi avaliar a presença de organismos semelhantes a Helicobacter e as alterações endoscópicas e histopatológicas em estômago de gatos domésticos de sangue tipo A. Amostras de antro, corpo e fundo gástricos foram coletadas de 32 gatos, sem raça definida, não domiciliados através de gastroscopia. Teste de urease e análise citológica foram realizados em amostras frescas. Secções teciduais foram processadas e coradas com hematoxilina e eosina e pela prata pelo método de Warthin-Starry para avaliação histológica. Helicobacter spp. foi detectado em 100% das amostras submetidas às análises citológicas e coloração pela prata e em 96,9% das amostras submetidas ao teste de urease. Em 87,5% dos gatos foi identificado infiltrado inflamatório mononuclear. A graduação e distribuição do infiltrado inflamatório nestes gatos revelaram alterações leves (78,1%) a moderada (9,4%) em pelo menos uma região gástrica. Estas alterações eram independentes do escore de colonização. Hiperplasia de folículos linfoides foram detectadas em 3 gatos. Gatos do grupo sanguíneo A são frequentemente colonizados por Helicobacter spp. e os achados macro e microscópicos são consistentes com estudos em gatos domésticos realizados até a presente data. Conclui-se que o grupo sanguíneo mais comum em gatos não está associado com uma alta susceptibilidade a gastrite sintomática causada por Helicobacter spp.(AU)

Sistema de grupos sanguíneos AB em felídeos neotropicais e compatibilidade com gatos domésticos / AB blood group system in neotropical felids and compatibility with domestic cats

O principal sistema de grupos sanguíneos reconhecido para gatos é o AB. Os felinos apresentam anticorpos naturais contra o antígeno do tipo sanguíneo a que não pertencem, o que torna os testes de compatibilidade e as tipagens sanguíneas importantes na prevenção de reações transfusionais. O objetivo deste estudo foi realizar a tipagem sanguínea de oito gatos-mouriscos (Puma yagouaroundi), oito jaguatiricas (Leopardus pardalis), sete gatos-palheiros (Leopardus colocolo), sete gatos domésticos (Felis catus) da raça Persa e oito gatos domésticos sem raça definida (SRD), bem como realizar testes de compatibilidade entre os tipos sanguíneos iguais das diferentes espécies, para avaliar a possibilidade de transfusões interespecíficas. A técnica empregada para a tipagem foi a hemaglutinação em tubos de ensaio. A ocorrência do tipo sanguíneo tipo A foi de 100% entre as jaguatiricas, os gatos-palheiros e os gatos Persas e de 85,72% entre os gatos SRD. A ocorrência do tipo B foi de 100% nos gatos-mouriscos e de 14,28% nos gatos SRD. Considerando os testes de compatibilidade sanguínea, 87,5% (n=4) das jaguatiricas foram incompatíveis com os gatos domésticos, 100% (n= 6) dos gatos-palheiros foram compatíveis com os gatos domésticos e 100% (n= 4) dos gatos-mouriscos foram incompatíveis com os gatos domésticos do tipo B.(AU)

The blood group system recognized for cats is AB. Antibodies against other blood types occur naturally in cats, which makes the compatibility tests and blood typing important for preventing transfusion reactions. Wild felids need blood transfusions in cases of diseases and when run over on highways. The aim of this study was to perform blood typing of eight jaguarundies (Puma yagouaroundi), eight ocelots (Leopardus pardalis), seven pampas cats (Leopardus colocolo), seven domestic cats (Felis catus) of Persian breed and eight non-pedigree domestic cats (Felis catus), and test compatibility among the different species with the same blood types, to evaluate the possibility of performing interspecific blood transfusions. We conducted the study from August to December. We used haemagglutination in test tubes for typing. The occurrence of blood type A was 100% among ocelots, pampas cats and domestic cats of Persian breed, while non-pedigree domestic cats showed 85.72%. The occurrence of type B was 100% for jaguarundis and 14.28% for non-pedigree domestic cats. Regarding blood compatibility tests, 87.5% (n= 4) of the ocelots were incompatible with domestic cats; 100% (n=6) of the pampas cats were compatible with domestic cats, while 100% (n=4) of the jaguarundis were incompatible with type B domestic cats.(AU)

Alloimmunisation in transfused patients: serial cross-matching in a population of hospitalised cats.

Objectives Cross-matching is currently recommended as part of pre-transfusion testing for repeat transfusions in cats 4 days after having received an initial transfusion. This prospective study determined when and if cats developed positive cross-match (CM) results after having been transfused with AB-compatible blood. Methods Donors were selected according to standard transfusion safety protocols. Twenty-one hospitalised anaemic recipients (blood type A: n = 20; blood type B: n = 1) received 1-4 (median 2) whole blood transfusions (WBTs) over 1-6 days (median 2) in 33 transfusion instances. The tube CM method, including major, minor and recipient control, was employed. Macroscopic and microscopic agglutination reactions were evaluated according to a predetermined scale. CM tests with a positive recipient control could not be evaluated. Results No signs of an acute transfusion reaction were observed. A total of 63 CMs were performed. In one cat with immune-mediated haemolytic anaemia the CM could not be evaluated (positive recipient control). The minor CM was negative in all cases. Fifteen of 20 cats had a negative major CM (MCM) 1-12 days (median 5) after their first transfusion. A positive MCM was observed in five cases after 2-10 days (median 5) post-first WBT. These five cats had received a total of 1-4 (median 2) WBTs. Cats with a negative MCM had received 1-3 (median 2) WBTs. In 51.5% (17/33) of transfusion instances, the cat's haematocrit increased as expected, with cats with a positive MCM at 40% (4/10) vs 56.5% (13/23) if MCM was negative. Conclusions and relevance Twenty-five percent (5/20) of the feline recipients likely developed alloantibodies against erythrocyte antigens outside of the AB system as early as 2 days post-first WBT. This adds data to the recommendation to include cross-matching in pre-transfusion screening tests.

Evaluation of a novel feline AB blood typing device.

This prospective study evaluated a novel immunochromatographic (IC) blood typing test for the AB blood group system. Typing was conducted comparatively on ethylenediamine tetra-acetic acid-anticoagulated blood samples from 89 sick and 16 healthy cats with the IC test, as well as two tests as reference methods, a tube agglutination and a gel column test. The samples were between 0 and 10 days old (median 3 days) and were tested for haemolysis and agglutination; the packed cell volume ranged from 0.07 to 0.57 l/l (median 0.40 l/l). The reference methods agreed with each other in 100% of the test runs. Of the 85 samples tested as blood type A by the two reference methods, 80 were correctly identified by the IC test, four were misidentified as AB and one was rated inconclusive. All B samples were correctly typed. Two of the three AB samples were correctly identified by the IC test and one was rated inconclusive. The sample quality had no influence on test performance. Of 30 repeats, 28 were readable and showed agreement in 27 cases. The agreement of the IC test with the control methods was 96.1% for the 103 conclusive tests, and it showed high sensitivity and specificity for A and B antigen detection. It is suggested that AB results be reconfirmed with a laboratory method and that a 'back-typing' be performed with plasma from B samples to detect the presence of alloantibodies. Given its very good performance and ease of use, the IC test can be recommended for clinical settings.

Frequência dos antígenos eritrocitários do sistema AB em felinos domésticos no estado da Paraíba / Frequency of AB blood System in domestic cats of Paraíba, Brazil

Objetivou-se com este estudo determinar a frequência de antígenos eritrocitários do sistema AB em felinos domésticos da Paraíba, Brasil. Foram selecionados aleatoriamente 178 gatos, clinicamente saudáveis, sem pré-requisitos quanto a sexo ou raça, com peso corporal acima de 1,5 kg e faixa etária acima de um ano de idade, abordados no ato da consulta ambulatorial em clínicas médicas de pequenos animais distribuídas entre três cidades da Paraíba (João Pessoa, Campina Grande e Patos). A determinação dos tipos sanguíneos foi realizada através do teste de hemaglutinação em tubo de ensaio e, a tipagem reversa foi realizada para as amostras tipos B e AB para confirmação e evidenciação de aloanticorpos naturais. Neste estudo a frequência relativa de antígenos eritrocitários A, B e AB em sua totalidade para felinos sem raça foram 98,1%, 1,21% e 0,69%, respectivamente. Todos os felinos com definição racial foram do tipo sanguíneo A. Diante destes, a probabilidade de ocorrência de reações transfusionais aleatórias obtidas foi de 2,78%, sendo cerca 40% (1,11%) potencialmente fatais. Desta forma, dado o conhecimento da frequência dos diferentes tipos sanguíneos em felinos, de uma determinada região, conclui-se que a tipagem sanguínea e o teste de compatibilidade, são importantes ferramentas que permitem ao médico veterinário tomar medidas preventivas que minimizem riscos de ocorrência de reações transfusionais e isoeletrólise neonatal e, estabelece pré-requisitos a respeito dos riscos de procedimentos hemoterápicos em felinos que circunstancialmente necessitem serem conduzidos de forma aleatória.

The objective of this study was to determine the frequency of the AB blood group antigens system in domestic cats of Paraíba, Brazil. We randomly selected 178 cats which were clinically healthy, with no prerequisites in terms of gender or race, weighing above 1.5 kg, and were over one year of age. These cats were randomly selected when they entered the small animal clinic facilities in the cities of João Pessoa, Campina Grande and Patos. The determination of blood types was made using the hemagglutination test tube, and the reverse typing was performed for samples B and AB types and for confirmation of alloantibodies natural disclosure. In this study the relative frequency of A, B and AB blood group antigens in cats without a determined breed was 98.1%, 1.21% and 0.69% respectively. All cats with breed definition were blood type A. The likelihood of random transfusion reactions was 2.78%, approximately 40% (1.11%) potentially fatal. Thus, given knowledge of the frequency of different blood types in cats, from a given region, it is concluded that blood typing and compatibility test are important tools that enable the veterinarian to take preventative measures to minimize risks of isoelectrolisys reactions and neonatal transfusion, and establishes prerequisites about the risks of hemotherapic procedures in cats that require circumstantially to be conducted randomly.

Assessment of feline blood for transfusion purposes in the Dublin area of Ireland.

The prevalence of A, B and AB blood types and of feline immunodeficiency virus (FIV) and feline leukaemia virus (FeLV) infection was determined in cats in Ireland, in order to determine risk factors for blood taken for transfusion purposes. EDTA blood samples were available from 137 non-pedigree cats and 39 pedigree cats (91 females and 85 males, aged four months to 15.0 years) in the Dublin area of Ireland. Of the 176 EDTA blood samples obtained, 112 (from 92 healthy cats and 20 sick cats) were tested for the presence of both FIV antibodies and FeLV antigens. Blood typing was performed using an immunochromatographic cartridge (CHROM; Alvedia). Testing for FIV and FeLV was performed by ELISA (SNAP FIV/FeLV Combo Test; Idexx Laboratories). Of the 39 pedigree cats, the majority (38 [97.4 per cent]) was type A, and only one (2.6 per cent) was type B. Of the 137 non-pedigree cats, the majority (116 [84.7 per cent]) was type A, 20 (14.6 per cent) were type B, and one (0.7 per cent) was type AB. Of the 92 healthy cats tested, the prevalence of FIV and FeLV positivity was 4.35 and 1.09 per cent, respectively. None of the 20 sick cats tested was FIV-positive; two (10 per cent) of the 20 sick cats were FeLV-positive.

Feline blood transfusions: A pinker shade of pale.

PRACTICAL RELEVANCE: blood transfusions are a potentially life-saving procedure that are within the reach of most small animal practitioners. Only minimal equipment is required. PATIENT GROUP: any cat with clinical signs attributable to a reduced red blood cell mass that is affecting oxygen transport (as a result of reduced packed cell volume or acute blood loss) is a potential candidate for a transfusion. CLINICAL CHALLENGES: although the principles of transfusion medicine are not complicated, there can be fatal consequences if certain steps are omitted. DIAGNOSTICS: blood typing kits and blood filters are readily available from veterinary wholesalers, laboratories and blood banking services. EVIDENCE BASE: over the past three decades, a substantial body of clinical research and reports has built up covering feline blood types and transfusion medicine. This article draws on that research to provide clinical guidance aimed at all veterinarians in feline or small animal practice who either currently practise transfusion medicine or plan to do so.

Blood types in Bengal cats in the UK.

Blood samples from 100 adult Bengal cats from the UK were submitted for assessment of blood type using RapidVet-H Feline blood typing cards (dms Laboratories), with further assessment by standard blood typing in a microtitre plate assay when card typing was inconclusive or revealed blood type B or AB. Ninety-eight cats were found to be type A when assessed using the blood typing cards. One cat initially tested as type AB but was found to be type A on testing a second blood sample using the blood typing cards. One cat initially tested as type B but was found to be type A when a second sample was tested by standard blood typing assay. Finding that 100% of the cats were blood type A is in contrast with previous studies that reported 10 Bengal cats to be type A, four to be type AB and one to be type B.

Multiple red cell transfusions in 27 cats (2003-2006): indications, complications and outcomes.

The objectives of this study were (1) to evaluate the indications, complications and outcomes of multiple red cell transfusions (MrcTs) in cats; of these cats (2) to describe those that received massive transfusion and (3) compare them with those who received MrcTs over a longer time course. Twenty-seven cats were identified which received a total of 110 transfusions, with a median of three transfusions (range 3-15) per cat. The transfusions consisted of 47 units of whole blood and 63 units of packed red blood cells. The median age of cats was 6 years (range 6 months to 15 years). Cats were hospitalized for a median of 6 days, with a range of 1-38 days. No acute transfusion reactions were documented, although due to the critical nature of the cats, they may not have been appreciated. Sixteen cats survived to discharge and 11 died or were euthanased. Indications (and % survival) for transfusions included bone marrow failure (n=8; 50%); surgical loss (n=4; 100%), sepsis (n=3; 0%), neoplasia (n=3; 33%), acute renal failure (n=3; 66%), trauma (n=2; 100%), gastrointestinal bleeding (n=1; 100%), and cats with multiple disease processes (n=3; 33%). MrcTs are well-tolerated in cats and may be associated with a favorable outcome.

Response of white leghorn chickens of various B haplotypes to infection at hatch with subgroup J avian leukosis virus.

White leghorn chickens from seven 15.B congenic lines (genetically similar except for genes linked to the major histocompatibility complex [MHC] B haplotype) and two Line 0.B semicongenic lines were infected at hatch with strain ADOL Hc-1 of subgroup J avian leukosis virus (ALV-J). At 5, 8, 16, and 36 wk of age, chickens were tested for viremia, serum-neutralizing antibody, and cloacal shedding. Chickens were also monitored for development of neoplasia. In the 15.B congenic lines (B*2, B*5, B*12, B*13, B*15, B*19, and B*21) there were no significant differences in the incidence of viremia between B haplotypes. In fact, infection at hatch in all of the 15.B congenic lines induced tolerance to ALV-J because 100% of these chickens were viremic and transient circulating serum-neutralizing antibody was detected in only a few chickens throughout the 36 wk experiment. However, at 16 wk of age more B*15 chickens had antibody and fewer B*15 chickens shed virus than did the 16-wk-old B*2, B*5, or B*13 chickens. Moreover, compared with B*15 chickens, a higher percentage of B*13 chickens consistently shed virus from 8 wk postinfection to termination at 36 wk postinfection. The B haplotype had a transient effect on viral clearance in Line 0.B semicongenics, as more B*13 than B*21 chickens remained viremic through 5 wk of age. Very few (0%-18%) of the Line 0.B semicongenic chickens shed virus. By 36 wk of age, all Line 0 B*13 and B*21 chickens produced serum-neutralizing antibodies and cleared the virus. These results show that following ALV-J infection at hatch the immune response is influenced transiently by the B haplotype and strongly by the line of chicken. Although this study was not designed to study the effect of endogenous virus on ALV-J infection, the data suggest that endogenous virus expression reduced immunity to ALV-J in Line 15I5, compared with Line 0, a line known to lack endogenous virus genes.

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.

Whole blood transfusions in 91 cats: a clinical evaluation.

This survey assessed the feline transfusion practices at the University of Berlin from 1998 to 2001 in regard to patient population, indications, efficacy, and transfusion reactions. Blood was obtained from seven healthy in-house donors and 127 mostly indoor client-owned pet cats. Over a 3-year period 91 cats were transfused with blood type compatible blood. The blood was fresh (within 8 h of collection) or stored no longer than 15 days. Transfusions were required because of blood loss anaemia (n=40), haemolytic anaemia (n=13), ineffective erythropoiesis (n=35), hypoproteinaemia (n=2) or coagulopathy (n=2). The anaemic cats had a pretransfusion haematocrit of 5-20% (m [median]=13), and received one to six transfusions (m=1). The survival rates of the anaemic cats at 1 and 10 days after transfusion were 84 and 64%, respectively. None of the deaths appeared to be related to transfusion reactions. The major crossmatch, undertaken before 117 transfusions, was incompatible for eight cats. All except for one had previously been transfused. Lysis of transfused cells in six cases resulted in a less than expected haematocrit rise and an increase in serum bilirubin. Transient mild transfusion reactions were only noted in two cats during the second or third transfusion. In conclusion, with proper donor selection and appropriate compatibility screening, blood transfusions are well tolerated, appear effective, and may increase chances of survival.