Christiane Weingart

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.

Haemorrhage in seven cats with suspected anticoagulant rodenticide intoxication

Clinical features were evaluated in seven adult cats (six males, one female) with haemorrhage and presumptive anticoagulant rodenticide intoxication. Haemorrhage appeared as thoracic haemorrhage, otic bleeding, haematoma, melena, haematochezia, and petechiation. The most common other presenting signs were lethargy, anorexia, and tachypnoea or dyspnoea. Six cats were anaemic, four cats were mildly thrombocytopenic (58 000–161 000/μl), and three had slightly decreased plasma protein or albumin values. The prothrombin time (30.3–>100 s, reference range: 16.5–27.5 s) and activated partial thromboplastin time values (32.6–>100 s; reference range: 14–25 s) were markedly prolonged in all cats. All cats received vitamin K1 subcutaneously or orally (3.7–5 mg/kg body weight initially) and depending on severity of signs five cats were transfused with fresh whole blood. Plasma coagulation times improved in all cats and returned to normal in 1–5 days. Rodenticide poisons represent an important but relatively rare cause of haemorrhage in cats and can be effectively treated.

Clinical use of a haemoglobin-based oxygen carrying solution (Oxyglobin®) in 48 cats (2002–2006)

The objective of this retrospective study was the evaluation of the administration of a haemoglobin (Hb)-based oxygen carrying solution (Oxyglobin®) to cats over a time period of 4 years. Indication, infusion volume/24 h, number of Oxyglobin® infusions/cat, Hb concentration pre- and post-infusion, adverse events, and patient outcome were evaluated. Forty-eight anaemic cats received 65 Oxyglobin® infusions. Prior to administration of Oxyglobin®, Hb concentration ranged from 2 to 7.8 g/dl (median 4.9 g/dl), the volume of Oxyglobin® administered was 4.4–25 ml/kg/24 h (median 9.8 ml/kg/24 h). An increase of Hb was noted after 41 of 49 infusion events. Severe side effects were noted in seven cats with cardiac disease, which developed pulmonary oedema (five), pleural effusion (three), and respiratory distress (one). They received 6.7–19.8 ml/kg/24 h (median 12.3 ml/kg/24 h) of Oxyglobin®. Four of these seven cats received whole blood transfusions on the same day; five cats died and one was euthanased. Overall 24-h survival rate was 77%. Administration of Oxyglobin® efficiently increased the Hb concentration. However, in cats suffering from cardiac disease, there is a high risk of life-threatening circulatory overload at the doses used in this study.

Concentration of D-dimers in healthy cats and sick cats with and without disseminated intravascular coagulation (DIC)

The objective of this prospective study was to measure concentrations of D-dimers in 48 cats with various diseases and in 20 healthy cats to evaluate the sensitivity and specificity for D-dimers to diagnose disseminated intravascular coagulation (DIC). The cats were classified as having DIC if an underlying disease and at least three of the following criteria were present: thrombocytopenia, prolonged activated partial thromboplastin time, prothrombin time or thrombin time, schistocytes and/or a reduced antithrombin activity. D-dimer concentrations were measured using a semi-quantitative latex agglutination (LA) test (Accuclot D-Dimer, Sigma Diagnostics). The D-dimer test was positive for 8/12 cats with DIC and for 16/36 sick cats without DIC. D-dimers were negative for all healthy control cats. The comparison of the sick cats with DIC and those without DIC revealed a specificity and sensitivity of the D-dimer test of 56% and 67%; a comparison of the results for healthy cats and cats with DIC revealed a specificity and sensitivity of 100% and 67%, respectively. The D-dimer LA test is only of limited value for the diagnosis of DIC in cats.

Primary immune-mediated thrombocytopenia in cats.

Feline primary immune-mediated thrombocytopenia (pIMT) is a rare condition, and only a few cases have been described in veterinary literature. Five cats with severe thrombocytopenia most likely due to pIMT are described. A flow cytometry platelet-bound antibody test was positive in all cats; underlying diseases or triggering factors causing thrombocytopenia were not detected. Three cats were transfused with blood type-compatible fresh whole blood; one cat received Oxyglobin as well. All cats were treated with prednisolone; one cat received chlorambucil in addition. Four cats responded to treatment and were discharged from the hospital. One cat was euthanized due to dyspnea. Primary immune-mediated thrombocytopenia is rarely diagnosed in cats, but it is important as a differential diagnosis in cats presented with surface bleeding.

Infection with haemoplasma species in 22 cats with anaemia

Objectives Information regarding the clinical course of natural infection with feline haemotropic mycoplasmas (haemoplasmas) is limited. The objective of the study was to describe the clinical findings and course of disease in naturally infected cats with haemoplasmosis and anaemia. Methods A retrospective analysis was performed on patient data from cats presenting with anaemia and haemoplasma infection regarding signalment, clinical signs, laboratory data and course of infection. The diagnosis was confirmed by conventional haemoplasma PCR analysis. Results Haemoplasma infection was found in 22 anaemic (haematocrit 5–25% [median 17%]; reference interval 30–44%) cats (‘Candidatus Mycoplasma haemominutum’, n = 12; Mycoplasma haemofelis, n = 3; ‘Candidatus Mycoplasma turicensis’, n = 2; species not determined, n = 4; coinfection with all three species, n = 1) between 2005 and 2014. Thirteen of the cats had concurrent diseases. All cats underwent antibiotic treatment; 15 cats received blood products. Six cats were euthanased within 11 weeks owing to concurrent disease, persistent severe anaemia or financial constraints. Ten cats underwent follow-up for a period of 14–199 weeks (median 26 weeks). Haemoplasma PCR was negative in 5/7 cases after 3–23 weeks. PCR remained positive in two cases after 18 and 199 weeks, respectively. Reactivation of the haemoplasma infection occurred in two cats, once and three times, respectively, up to 177 weeks after initial presentation. Reactivation was suspected in two further cases. Owing to concurrent disease, four of the 10 follow-up cats were euthanased 14–180 weeks after initial presentation. Conclusion and relevance Infection with haemoplasma species is often chronic, can reactivate months later and is rarely a reason for euthanasia.

Evaluation of the tolerability and immunogenicity of ultraviolet C-irradiated autologous platelets in a dog model

BACKGROUND: The THERAFLEX ultraviolet (UV) platelets (PLTs) pathogen reduction system for PLT concentrates (PCs) operates using ultraviolet C (UVC) light at a wavelength of 254 nm. UVC treatment can potentially alter proteins, which may affect drug tolerance in humans and influence the immunogenicity of blood products. This preclinical study in beagle dogs was designed to evaluate the safety pharmacology of UVC‐irradiated PCs after intravenous administration and to determine whether they are capable of eliciting humoral responses to PLTs and plasma proteins.

Measurement of β-hydroxybutyrate in cats with nonketotic diabetes mellitus, diabetic ketosis, and diabetic ketoacidosis

Diabetic ketoacidosis (DKA) is a life-threatening complication of diabetes mellitus (DM). The standard method of detection of ketone bodies is the dipstick method, which detects semiquantitatively acetoacetate, but not β-hydroxybutyrate (β-HB). The objectives of the current study were to assess the diagnostic utility of β-HB to diagnose diabetic ketosis (DK) and DKA in cats and to establish a cut-off value for the diagnosis of DKA. Sixty-two cats were included in the study. Eleven cats were healthy (group 1); in the remainder of cats (51), a diagnosis of DM was based on hyperglycemia, glucosuria, and increased fructosamine concentrations. Nineteen of 51 cats suffered from nonketotic diabetes mellitus (group 2). In 11 cats, plasma ketone bodies were detected with the dipstick method (diabetic ketosis, group 3). In 21 cats, plasma ketone bodies and metabolic acidosis were present (DKA, group 4). Plasma β-HB was measured in all cats by an enzymatic method (spectrophotometry). A cut-off value for the diagnosis of DKA was calculated based on the receiver operating characteristic curve. In healthy cats, the β-HB concentration ranged from 0 to 0.1 mmol/l; in cats of group 2, from 0 to 0.9 mmol/l (median: 0.1 mmol/l); in cats of group 3, from 0.6 to 6.8 mmol/l (median: 1.7 mmol/l); and in cats of group 4, from 3.8 to 12.2 mmol/l (median: 7.9 mmol/l). A cut-off value of 2.4 mmol/l revealed 100% sensitivity and 87% specificity to diagnose DKA. Beta-hydroxybutyrate is a useful parameter for the diagnosis of diabetic ketosis and DKA in cats.

Validation of a portable hand‐held whole‐blood ketone meter for use in cats

BACKGROUND Urinary dipsticks are the most frequent method used for screening of ketones in animals, but this method has many drawbacks. In human medicine, portable meters that measure ketones in whole blood have largely replaced urinary dipsticks. OBJECTIVE The aim of this prospective study was to validate a portable whole-blood ketone meter for use in cats. METHODS Sixty-two cats (11 clinically healthy, 51 with diabetes mellitus) were included in the study. The concentration of β-hydroxybuyrate (β-HB) was measured in venous and capillary blood with a hand-held ketone meter (Precision Xceed; assay range 0-8 mmol/L) and compared with a spectrophotometric method. Precision, accuracy, and the effects of hematocrit and anticoagulants were evaluated. RESULTS Between-run precision using low- and high-concentration control solutions was 8.1% and 2.6%, respectively; within-run coefficient of variation determined using 12 feline blood samples was 2.8%. In the 62 cats, β-HB concentrations measured with the portable ketone meter ranged from 0-7.4 mmol/L (median 0.9 mmol/L). When β-HB concentrations measured by the portable meter were < 4.0 mmol/L there was good agreement with the reference method, but concentrations > 4.0 mmol/L were lower than those obtained by the reference method in 20 of 24 cats (83%). There was good correlation between capillary and venous measurements. Results were not affected by hematocrits from 0.17 to 0.50 L/L, but EDTA was not a suitable anticoagulant. CONCLUSION Measurement of β-HB concentration in peripheral or capillary blood by an easy-to-use portable ketone meter was suitable for detecting ketonemia in cats. Underestimation of β-HB concentration was observed at higher values, but results were sufficiently high to aid in diagnosing diabetic ketoacidosis.

Clinical evaluation of the QuickVet®/RapidVet® canine dog erythrocyte antigen 1.1 blood-typing test

In transfusion medicine, blood typing is an integral part of pretransfusion testing. The objective of the current study was the clinical evaluation of an automated canine cartridge dog erythrocyte antigen (DEA) 1.1 blood-typing method (QuickVet®/RapidVet®) and comparison of the results with a gel column–based method (ID-Gel Test Canine DEA 1.1). Ethylenediamine tetra-acetic acid–anticoagulated blood samples from 11 healthy and 85 sick dogs were available for typing. Before blood typing, all samples were tested for agglutination and hemolysis. All samples were tested once or multiple times with both methods according to the manufacturer’s guidelines. With the gel method, 53 dogs tested DEA 1.1 positive and 42 dogs DEA 1.1 negative; blood typing was not possible due to erythrocyte autoagglutination in 1 dog. With the cartridge test, 53 samples tested DEA 1.1 positive, 34 samples tested DEA 1.1 negative, and 6 results were inconclusive (3 samples were not included due to autoagglutination or severe hemolysis). Without taking the inconclusive samples into account, the agreement between both methods was 96.5%. The sensitivity and specificity for samples that were definitively typed by both methods were 100% and 91.9%, respectively. The cartridge test was suitable for in-clinic canine DEA 1.1 blood typing, although some discrepancies compared to the gel method existed. The cartridge test is software-directed, is easy to use, and does not require user interpretation, but preanalytical guidelines (sample evaluation for agglutination and hemolysis) have to be followed. For inconclusive results, an alternate blood-typing method should be performed.