Anemia In Cats Research Articles

Approach to diagnosing and managing anaemia in cats

Background: The primary role of red blood cells (RBCs) is the safe transport of oxygen‐carrying haemoglobin from the lungs to the capillary beds. Anaemia is a common clinical and clinicopathological finding in cats, occurring when functional haemoglobin concentrations in blood are reduced. Although commonly attributed to a reduction in RBC numbers or mass, a reduced mean cell haemoglobin concentration and, rarely, haemoglobinopathies can also contribute. Clinical signs of anaemia range from subclinical to severe and life threatening, and primarily relate to reduced oxygen carrying capacity. Other signs relating to acute volume loss (eg, following haemorrhage), inflammation (eg, due to haemolysis) or the pathology underlying the anaemia may be of greater clinical relevance. The differential list for anaemia itself is long, but careful evaluation of clinicopathological changes can allow clinicians to narrow this list and focus investigation.Aim of the article: This article discusses the common causes of anaemia in cats and how to make a definitive diagnosis, as well as the treatment options to correct the underlying cause.

Understanding anaemia in cats and how to optimise treatment

Understanding anaemia in cats and how to optimise treatment

The prevalence of murmurs and gallop sounds in anemic cats.

There is little information on the prevalence of auscultatory abnormalities in anemic cats. This study aimed to describe the prevalence of cardiac murmurs and gallop sounds in a population of anemic and nonanemic cats presenting to an emergency room (ER) and to assess whether the prevalence of auscultatory abnormalities was influenced by the severity of anemia. Records of cats presenting to an ER between May 2021 and May 2022 or receiving a blood transfusion between September 2019 and January 2022 were retrospectively analyzed for presence of a murmur or gallop sound. Cats with known structural heart disease were excluded. A murmur was found in 56 of 185 (30%) anemic cats compared with 11 of 102 (11%) nonanemic cats (p<0.001), with a higher proportion in cats with PCV <16% (p<0.001). Twenty-five of 185 (14%) anemic cats had a gallop compared with 4 of 102 (4%) nonanemic cats (p=0.009), with the highest proportion in cats with PCV 11%-20% (p<0.001). Echocardiography was performed on 17 of 185 anemic cats; 8 had normal echocardiograms and 9 demonstrated evidence of chamber dilation without left ventricular wall thickening, consistent with anemia. Abnormalities on auscultation are common in anemic cats presenting to the ER, with a higher prevalence in more severely anemic cats.

Using RET-He and Delta-He in the Sysmex XN-1000V Analyzer to Differentiate Between Chronic Hemorrhagic and Chronic Inflammatory Anemia in Small Animals.

Chronic hemorrhagic anemia (CHA) and anemia of chronic inflammation (ACI) are difficult to differentiate in small animals using hematology. Advanced hematological parameters (RET-He, Delta-He and %Hypo-He) are used in humans to discriminate between types of non-regenerative anemia. Whether they could be useful in the diagnosis of CHA and ACI in small animals is unknown. We evaluated these parameters in the Sysmex XN-1000V analyzer in a population of non-anemic and anemic dogs and cats. Delta-He was significantly different between dogs with CHA and ACI. Moreover, Delta-He and RET-He were different between healthy and non-anemic dogs with inflammation. Neither of these two statements was true for cats. We also report the reference ranges for these parameters using the Sysmex XN-1000V. Although additional clinical and laboratory information should always be considered, the measurement of these parameters using this analyzer can help clinicians to classify type of anemia.

Evaluation of darbepoetin therapy on platelet count and function in healthy cats and cats with surgically induced chronic kidney disease.

To evaluate the effects of darbepoetin on platelet population and reactivity in healthy cats (HCs) and azotemic cats with remnant kidney (RK) model-induced chronic kidney disease. 12 purpose-bred domestic shorthair cats (n = 6 HCs and n = 6 RK). In this pilot study, all cats received darbepoetin (1 µg/kg, SC) on days 0, 7, and 14. Blood was sampled at baseline and on days 3, 10, 15, 17, 20, and 21. At each time point, a CBC was performed, platelet aggregometry was assessed by impedance and optical methods, and platelet P-selectin (CD62P) was quantified before and after thrombin stimulation. Additionally, reticulated platelets were quantified using both thiazole orange staining and proprietary analysis by the CBC analyzer. For RK cats, systemic blood pressure (BP) was serially measured. No adverse effects of darbepoetin were seen. There was no statistically significant change in platelet count between or within groups at any time point. Hematocrit increased significantly over time in the RK but not the HC group. RBC reticulocyte numbers in both groups increased over time. Reticulated platelet percentage did not increase in either group. Differences in platelet reactivity within or between groups were not seen in the aggregometry or flow cytometric assessments. In RK cats, indirect BP did not significantly change during the study. This preliminary investigation did not find evidence that darbepoetin administration impacted platelet number, reactivity, nor reticulated platelet count. Anemic RK cats experienced increased hematocrit and RBC reticulocytes as expected with darbepoetin therapy.

The Effect of a Subsequent Dose of Dexmedetomidine or Other Sedatives following an Initial Dose of Dexmedetomidine on Electrolytes, Acid-Base Balance, Creatinine, Glucose, and Cardiac Troponin I in Cats: Part II.

The administered dose of dexmedetomidine may occasionally fail to produce the anticipated sedative effects. Therefore, a subsequent dose or administration of another sedative may enhance sedation; however, patient safety may be affected. The safety of seven different drugs administered at the following time point after an insufficient dose of dexmedetomidine was evaluated in a crossover, blind, experimental study that included six healthy adult cats. All cats received an initial dose of dexmedetomidine and a subsequent dose of either dexmedetomidine (Group DD), NS 0.9% (DC), tramadol (DT), butorphanol (DBT), buprenorphine (DBP), ketamine (DK), or midazolam (DM). Animal safety was assessed using repeated blood gas analysis and measurement of electrolytes, glucose, cardiac troponin I, and creatinine to evaluate cardiac, respiratory, and renal function. The median values of creatinine, cardiac troponin I, pH, partial pressure of carbon dioxide, potassium, and sodium did not change significantly throughout the study. Heart rate was significantly decreased in all groups after administration of the drug combinations, except for in the DK group. Respiratory rate decreased significantly after administration of the initial dose of dexmedetomidine and in the DBP and DM groups. The partial pressure of oxygen, although normal, decreased significantly after the administration of dexmedetomidine, whereas the median concentration of glucose increased significantly following the administration of dexmedetomidine. The results of our study suggest that the drug combinations used did not alter the blood parameters above normal limits, while cardiac and renal function were not compromised. Therefore, a safe level of sedation was achieved. However, the administration of dexmedetomidine reduced the partial pressure of oxygen; thus, oxygen supplementation during sedation may be advantageous. Additionally, the increase in glucose concentration indicates that dexmedetomidine should not be used in cats with hyperglycaemia, whereas the decrease in haematocrit suggests that dexmedetomidine is not recommended in anaemic cats.

The Immature Reticulocyte Fraction (IRF) in the Sysmex XN-1000V Analyzer Can Differentiate between Causes of Regenerative and Non-Regenerative Anemia in Dogs and Cats.

The Sysmex XN-1000V analyzer can identify those reticulocytes with high RNA content and fluorescence, providing the immature reticulocyte fraction (IRF). While this parameter has been used in human medicine to identify the cause of anemia, few studies have focused on its use in veterinary medicine. In this study, we determined the IRF and related reticulocyte parameters in a large population of non-anemic and anemic dogs and cats (subclassified depending on the origin of their anemia). The IRF was significantly higher in hemolytic anemias compared to hemorrhagic ones in both species. Moreover, the IRF was significantly lower in dogs and cats with bone marrow failure than in other non-regenerative anemias and in both groups compared to pre-regenerative anemias. The accurate cut-off values for the differential in regenerative anemias and reference ranges for both species using the Sysmex XN-1000V are also reported. The measurement of the IRF in this analyzer can help clinicians to further classify the type of anemia in both species.

Adeno-associated virus-vectored erythropoietin gene therapy for anemia in cats with chronic kidney disease.

A treatment of chronic kidney disease (CKD)-associated anemia in cats is needed. SB-001 is an adeno-associated virus-vectored (AAV)-based gene therapeutic agent that is administered intramuscularly, causing the expression of feline erythropoietin. We hypothesized that SB-001 injection would lead to a sustained increase in PCV in cats with CKD-associated anemia. Twenty-three cats with International Renal Interest Society (IRIS) Stage 2 to 4 CKD-associated anemia were enrolled at 4 veterinary clinics. In a prospective clinical trial, cats were treated with 1 of 3 regimens of SB-001 (Lo 1.2 × 109 genome copies [GCs] on Day 0; Lo ± Hi [supplemental 2nd dose of 3.65 × 109 GC on Day 42]; Hi 3.65 × 109 GC IM on Day 0) and followed for 70 days. A response to SB-001 at any time between Day 28 and Day 70 was seen in 86% (95% confidence interval 65, 97%) of all cats. There was a significant (P < .003) increase in PCV from Day 0 to Day 28 (mean increase 6 ± 6 percentage points [pp]; n = 21), Day 42 (8 ± 9 pp; n = 21), Day 56 (10 ± 11 pp; n = 17), and Day 70 (13 ± 14 pp, n = 14). Twelve cats were hypertensive at baseline, 4 of which developed encephalopathy during the study. An additional 6 cats became hypertensive during the study. Results of this study suggest that SB-001 therapy represents a suitable single injection treatment that can address nonregenerative anemia in cats with CKD. It was generally well tolerated; however, hypertension and encephalopathy developed in some cats as previously described in association with erythropoiesis-stimulating agent therapy.

Use of molidustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, in chronic kidney disease-associated anemia in cats.

Erythropoietic effects of molidustat, a hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitor, were previously demonstrated in healthy cats. To evaluate the safety and erythropoietic effects of daily PO administration of molidustat in anemic cats with chronic kidney disease (CKD). Twenty-one client-owned CKD cats (4-17 years old) with anemia. Multicenter field study; randomized, masked, and placebo-controlled. Cats were treated PO once daily for 28 days with suspensions of control product (CP; n = 6) or 5 mg/kg of molidustat (n = 15). Hematocrit (HCT) was evaluated at weekly intervals. Individual cat treatment success was defined as a ≥4% point increase in HCT compared to baseline. Control group mean HCT remained low throughout the study (20.1%-23.4%). Mean HCT of molidustat-treated cats increased weekly, and a significant increase compared to baseline (23.6%) was first observed on Day 21 (27.3%; P < .001; 95% confidence interval [CI], 1.69-5.67). Compared to CP group, mean HCT was significantly higher on Day 21 (27.3% vs 20.1%; P < .001; 95% CI, 2.91-10.75) but not significantly higher on Day 28 (27.8% vs 23.4%; P = .06; 95% CI, -0.23 to 9.88). The number of individual treatment successes on Day 28 was higher among remaining molidustat-treated cats (7/14) compared to remaining control cats (1/5), but there was no significant difference between groups. Daily PO molidustat administration may stimulate a clinically relevant erythropoietic response in anemic cats with CKD. This HIF-PH inhibitor may be an alternative for managing anemia in cats compared to recombinant EPO treatment.

Establishment of a feline glycated hemoglobin reference interval for a novel dried-blood-spot assay and the effects of anemia on assay results.

Glycated hemoglobin A1c (HbA1c) reflects long-term (months) glycemic control and has been previously investigated as a monitoring and diagnostic tool in diabetic cats. However, a standardized, reliable, and globally available test and reference intervals (RIs)have not been established. A novel dried-blood-spot card system (A1Care, Baycom Diagnostics) allows for easy collection and evaluation of HbA1c levels in feline patients. We aimed to establish an RI for HbA1c values in healthy adult cats using the A1Care (Baycom Diagnostics) dried-blood-spot card system. Forty-one healthy client-owned adult cats were enrolled in this study. The RI for HbA1c was calculated according to the recommendation of the American Society for Veterinary Clinical Pathology. The A1Care HbA1c RI for cats was determined to be 1.9%-3.1%. In healthy cats, A1Care HbA1c values were positively correlated with age (Spearman rho = 0.4 [95% CI 0.1 to 0.6], P = 0.01). In 50% of anemic cats, the A1Care HbA1c value was above 3.1%. There was a weak negative correlation between the A1Care HbA1c value and PCV (Spearman rho = -0.4 [95% CI -0.6 to -0.1]). This study established an RI for HbA1c in healthy adult cats similar to previously reported RIs. Future clinical studies are necessary to substantiate that this RI can differentiate diabetic from nondiabetic cats. Further long-term clinical studies will be valuable to determine if HbA1c values can be used as a screening test for prediabetes in cats.

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

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

Treatment of high-output cardiac failure secondary to anemia in three cats

Case series summary Three cats presented for clinical signs of respiratory distress and varying etiologies of anemia. Echocardiograms revealed evidence of cardiac dilation without other significant structural or functional heart disease. Thoracic imaging via point-of-care ultrasound and/or radiographs confirmed evidence of volume overload by pleural effusion. Each cat was diagnosed with presumed high-output cardiac failure secondary to anemia. Mainstays of treatment included controlling congestion and correcting the anemia with transfusions in the short-term while addressing the underlying etiology of the anemia in the long-term. Relevance and novel information Reports, treatment and management of high-output failure in the veterinary literature are limited. Extrapolating from human medicine, cats presenting with anemia and findings consistent with volume overload will benefit from treatment of their anemia to reduce neuroendocrine activation and the associated sodium and water retention. Therefore, blood transfusion should neither be avoided nor delayed in anemic cats with changes consistent with volume overload and congestive heart failure.

Retrospective prevalence and associated risk factors of Mycoplasma haemofelis infection in owned cats.

Data on the prevalence and associated risk factors of naturally occurring haemoplasmosis in owned cats in Malaysia is limited. Being the most pathogenic of the three known feline haemoplasma species, Mycoplasma haemofelis (Mhf) infection was analysed from 2016 to 2019 to determine the periodical prevalence and associated risk factors in Northeastern Malaysia - Kelantan. Archived patient data of 77 clinically ill cats suspected of having M. haemofelis infection were reviewed in this study. Out of the 77 suspected cases, 53 (68.8%) were clinically diagnosed with haemoplasmosis amongst which 46 (59.7%) of the subpopulation were further confirmed with polymerase chain reaction (PCR). Risk factors for M. haemofelis infection (age, breed, ectoparasitism, household condition, roaming status, and sex) were analysed. There was no significant association of breed, ectoparasitism, household condition (number of cats) and occurrence of clinical signs with feline mycoplasmosis. Young, male and roamer cats were more likely to be diagnosed of mycoplasmosis than other categories of cats in this study. There was also a significant association between cats infected with 'Candidatus Mycoplasma haemominutum' with M. haemofelis. Thus, the coinfection of these two haemoplasma species is not uncommon. This study indicates that infection by M. haemofelis in anaemic cats is a common find in client-owned cats from Northeastern Malaysia. As the natural mode of transmission of haemoplasma infection remain unestablished, information in this study may highlight the importance of this disease and contribute to effective prevention and control strategies to minimize feline infectious anaemia (FIA) caused by M. haemofelis.

Risk factors and clinical and laboratory findings associated with feline immunodeficiency virus and feline leukemia virus infections in Bangkok, Thailand.

Background and Aim:Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are retroviruses associated with chronic and neoplastic diseases in domestic and non-domestic cats. There has been increasing interest in the clinical importance of feline retroviruses in Thailand and the identification of associated risk factors in domestic cats. To prevent the spread of retroviral diseases and improve the management of retrovirus-infected cats, risk factors and associated clinical laboratory data must be clearly understood. This study aimed to identify the influence of household, lifestyle, health status, sterilization, clinical presentations, and laboratory findings on FIV- and FeLV-infected cats in Bangkok, Thailand.Materials and Methods:A total of 480 cats were evaluated for FeLV p27 antigen and FIV antibodies using Witness FeLV-FIV Rapid Test and SNAP FIV/FeLV Combo Test at a veterinary hospital service.Results:Of the 480 cats tested, 113 were positive for virus infection, including 60 for FeLV (12.5%), 40 for FIV (8.3%), and 13 for both FeLV and FIV (2.7%). The findings revealed that the risk factors for cats infected with FeLV, FIV, or both FeLV and FIV were significantly different compared with those for non-infected cats (p < 0.05). Multivariate analysis showed that multi-cat ownership is a risk factor for the high prevalence of feline retrovirus infection, as multi-cat households exhibited a higher prevalence of infection than single-cat households. Anemic and sick cats were also at a greater risk of testing positive for specific retrovirus infections. FeLV-infected cats had a higher risk of anemia and low erythrocyte and thrombocyte counts (p ≤ 0.0001), whereas FIV-infected cats were more likely to have anemia and leukocytopenia than controls.Conclusion:Knowledge of the risk factors for retroviral diseases and associated clinical and laboratory findings can be used to develop strategies to reduce FIV and FeLV infections in cats.

Cytauxzoon europaeus infections in domestic cats in Switzerland and in European wildcats in France: a tale that started more than two decades ago

BackgroundCytauxzoon spp. infection is believed to be a newly emerging tick-borne disease in felids in Europe, with three species of the haemoparasite having recently been differentiated in wild felids. In Switzerland, rare infections have been documented in domestic cats in the west and northwest of the country, the first of which was in 2014. The aims of the present study were: (i) to characterize a Cytauxzoon spp. hotspot in domestic cats in central Switzerland; (ii) to elucidate the geographic distribution of Cytauxzoon spp. in domestic cats in Switzerland; (iii) to assess suspected high-risk populations, such as stray and anaemic cats; and (iv) to investigate the newly emerging nature of the infection. Cytauxzoon spp. were further differentiated using mitochondrial gene sequencing.MethodsThe overall study included samples from 13 cats from two households in central Switzerland (study A), 881 cats from all regions of Switzerland (study B), 91 stray cats from a hotspot region in the northwest of Switzerland and 501 anaemic cats from across Switzerland (study C), and 65 Swiss domestic cats sampled in 2003 and 34 European wildcats from eastern France sampled in the period 1995–1996 (study D). The samples were analysed for Cytauxzoon spp. using real-time TaqMan quantitative PCR, and positive samples were subjected to 18S rRNA, cytochrome b (CytB) and cytochrome c oxidase subunit I (COI) gene sequencing.ResultsIn study A, six of 13 cats from two neighbouring households in central Switzerland tested postive for Cytauxzoon spp.; two of the six infected cats died from bacterial infections. In studies B and C, only one of the 881 cats (0.1%; 95% confidence interval [CI]: 0–0.3%) in the countrywide survey and one of the 501 anaemic cats (0.2%; 95% CI: 0–0.6%) tested postive for Cytauxzoon spp. while eight of the 91 stray cats in the northwest of Switzerland tested positive (8.8%; 95% CI: 3.0–14.6%). In study D, Cytauxzoon spp. was detected in one of the 65 domestic cat samples from 2003 (1.5%; 95% CI: 0–4.5%) and in ten of the 34 European wildcat samples from 1995 to 1996 (29%; 95% CI: 14.2–44.7%). The isolates showed ≥ 98.6% sequence identities among the 18S rRNA, CytB and COI genes, respectively, and fell in the subclade Cytauxzoon europaeus based on CytB and COI gene phylogenetic analyses.ConclusionsThe study challenges the newly emerging nature of Cytauxzoon spp. in central Europe and confirms that isolates from domestic cats in Switzerland and European wild felids belong to the same species.Graphical

Evaluation of the role of Babesia species and Cytauxzoon felis in feline anemia cases in Colorado, USA.

ObjectivesThe aim of this study was to evaluate the blood of cats in Colorado, USA, with suspected infectious causes of anemia for the presence of Babesia species and Cytauxzoon felis DNA. Results of PCR testing for other common vector-borne diseases potentially associated with anemia are also reported.MethodsSamples from 101 cats were tested using a PCR assay that coamplified the DNA of C felis and Babesia species mitochondrial DNA. PCR testing for DNA of hemoplasmas, Bartonella species, Ehrlichia species, Anaplasma species, Neorickettsia risticii and Wolbachia genera was also performed if not carried out previously.ResultsTwenty-two cats (21.8%) were positive for DNA of an infectious agent. DNA from hemoplasma species were amplified from 14 cats (13.9%). Bartonella species DNA was amplified from four cats (4%) and Ehrlichia canis, Anaplasma platys, Anaplasma phagocytophilum and Wolbachia genera DNA were amplified from one cat each. Babesia species and C felis mitochondrial DNA were not amplified from any sample.Conclusions and relevanceBased on the results of this study, it does not appear that Babesia species or C felis are clinically relevant in anemic cats in Colorado, USA. For C felis, this suggests that the vector Amblyomma americanum is still uncommon in this geographic area.

Left heart dimensions in anemic cats and dogs before and after blood transfusion.

BackgroundWhether anemic cats and dogs with increased left heart dimensions are at higher risk of transfusion‐associated circulatory overload, and the effect of blood transfusion on left heart dimensions in naturally occurring anemia is unknown.Hypothesis/objectivesTo evaluate the effect of blood transfusion on left heart dimensions in clinically relevant anemia.AnimalsTwenty dogs and 20 cats presenting to a university veterinary teaching hospital.MethodsIn this prospective observational study, anemic dogs and cats requiring blood transfusion were included. Packed cell volume (PCV), total solids, and echocardiography were performed before and within 24 hours of blood transfusion. Signalment, bodyweight, disease process, transfusion duration and volume, and prior treatments were recorded. Nonparametric statistics were reported as median [range]. Post hoc Bonferroni correction set significance at P < .006.ResultsAfter transfusion, PCV increased in cats (12% [6–16] to 18% [10‐33], P = .001) and dogs (14% [7–24] to 25% [9‐37], P = .001), heart rate decreased in dogs (104 bpm [86‐166] to 87 bpm [56‐138], P < .001), and fractional shortening decreased in cats (57.1% [36.0‐84.7] to 41.0% [28.1‐69.6], P = .002) and dogs (33.79% [19.33‐62.79] to 31.89% [19.06‐51.47], P = .006). Left ventricular internal diameter in systole increased in cats (6.5 mm [2.7‐9.8] to 7.9 mm [5.3‐11.1], P = .001). Normalized left ventricular internal diameter in diastole (1.48 [1.25‐1.79] to 1.57 [1.33‐2.00], P = .001) and systole (0.87 [0.58‐1.19] to 1.00 [0.74‐1.36], P = .001) increased in dogs. Incidence of volume overload did not differ before (14/20 cats, 70%; 9/20 dogs, 45%) or after (12/20 cats, 60%; 11/20 dogs, 55%) transfusion (P = .64).Conclusions and clinical importanceBlood transfusion is well tolerated when signs of volume overload are present before transfusion.

Exploration of risk factors for non-survival and for transfusion-associated complications in cats receiving red cell transfusions: 450 cases (2009 to 2017).

To describe red blood cell transfusion practices and short-term outcomes in anaemic cats. To determine clinical variables associated with non-survival and transfusion-related complications. In this retrospective study, blood bank records from the Ontario Veterinary College Health Science Centre (OVC-HSC) were reviewed to identify cats that received packed red blood cells or whole blood from 2009 to 2017. We extracted cause of anaemia, history of previous transfusion, pre- and post-transfusion packed cell volume, pre-transfusion compatibility testing, volume and dose of blood product, age of red blood cell unit, transfusion-associated complications and patient survival. A total of 450 transfusion events were recorded in 267 cats. Blood loss was the most common indication for blood transfusion (44.9%), followed by ineffective erythropoiesis (37.5%) and red blood cell destruction (22.5%). Transfusion-associated complications occurred in 10.2% events and there was a 20.2% mortality after transfusion. Mean increase in packed cell volume 24-hours after transfusion was greater in cats undergoing major cross-match testing before transfusion (7.2%) versus those that did not (4.0%). Non-survival was associated with higher packed cell volume before transfusion, low patient body temperature before transfusion, anaemia due to blood loss and number of transfusions administered. Older age of transfused blood units was associated with non-survival and transfusion-related complications. This study was observational and so our analyses were exploratory, but suggest that major cross-match before transfusion tended to have greater transfusion efficacy and transfusion of older blood products might have detrimental effects on survival.

Reticulocytosis in non-anaemic cats and dogs.

To evaluate the proportion of blood samples diagnosed with reticulocytosis without anaemia in cats and dogs and report the aetiology and mortality rate of affected animals. Retrospective multicentre study including haematological examination of 3956 cats and 11,087 dogs admitted to seven German veterinary clinics (2012 to 2014). The proportion of blood samples with reticulocytosis without anaemia was calculated, and after exclusion of multiple measurements of the same animal, clinical data were evaluated. Animals with reticulocytosis without anaemia were classified as healthy or diseased, and diseased patients were assigned to 12 disease groups. Pretreatment (i.e. non-steroidal anti-inflammatory drugs, glucocorticoids, dipyrone) was recorded. The proportion of blood samples with reticulocytosis without anaemia was 3·1% (124/3956) in cats and 4·4% (492/11,087) in dogs. Overall, 1·8% (2/111) of cats and 1·5% (7/458) of dogs with reticulocytosis without anaemia were healthy. Blood loss/anaemia, cardiac/respiratory disorders, gastrointestinal disorders and inflammatory disorders as well as cancer were the most frequent underlying diseases. Pretreatment was noted in 39·5% (43/111) of cats and 42·4% (194/458) of dogs. The mortality rate was 37·8% (42/111) in cats and 29·7% (136/458) in dogs with reticulocytosis without anaemia; the median survival time in non-survivors was 1day (range: 0 to 376 days in cats, 0 to 444 days in dogs). In both species, reticulocytosis without anaemia was observed in a low proportion of blood samples (dogs>cat). Though a bias towards sick animals is possible in our sample, reticulocytosis without anaemia was mainly seen in diseased animals and associated with a mortality rate of approximately one-third of patients.

Effect of cross-match on packed cell volume after transfusion of packed red blood cells in transfusion-naïve anemic cats.

BackgroundNovel feline RBC antigens might contribute to decreased efficacy of RBC transfusion and increased incidence of acute transfusion reactions (ATR).ObjectivesTo examine the effect of major cross‐match in transfusion‐naïve anemic cats on the incidence of acute immunologic transfusion reaction and transfusion efficacy for up to 24 hours after transfusion.AnimalsForty‐eight client owned transfusion‐naïve anemic cats.MethodsProspective, randomized, controlled study. All transfusion‐naïve cats receiving packed red blood cells (pRBC) transfusions from January 2016 to August 2017 were eligible for inclusion. Cats in the study group received cross‐match and blood type compatible pRBCs and cats in the control group received noncross‐matched blood type compatible pRBCs. Incidence of ATR and change in PCV after transfusion was recorded.ResultsNo significant difference in incidence of transfusion reactions between cross‐matched and noncross‐matched groups (CM+ 4/24; 17%, CM– 7/24; 29%, P = .16). No significant difference between groups in mean change in PCV after transfusion scaled to dose of pRBCs administered at any time point after transfusion (immediate: CM+ 0.62 ± 0.59, CM– 0.75 ± 0.48, P = .41; 1 hour: CM+ 0.60 ± 0.66, CM– 0.74 ± 0.53, P = .43; 12 hours: CM+ 0.70 ± 0.55, CM– 0.66 ± 0.60, P = .81; 24 hours: CM+ 0.64 ± 0.71, CM– 0.55 ± 0.48, P = .70).Conclusions and Clinical ImportanceOur results do not support use of the major cross‐match test to increase efficacy of, and to decrease adverse events associated with, RBC transfusion in AB blood typed transfusion‐naïve cats.