Background Blood typing for the A and B antigens is essential and crossmatching testing is generally recommended before transfusing blood to cats. Objective To evaluate 2 crossmatch (XM) tests. Animals Forty‐nine healthy domestic shorthair cats that had not received a blood transfusion. Methods Prospective study. Blood samples were typed for AB using immunochromatographic and flow cytometric techniques. A gel column (GC) and a feline antiglobulin‐enhanced gel column (AGC) XM tests were used for crossmatching. Results The population included 34 type A, 13 B, and 2 AB cats, with concordant results (r = 1, P < .005) by flow cytometry and immunochromatographic strip kit. The plasma from type A cats had either no or weak anti‐B alloantibodies. The plasma of 12 of 13 type B cats contained strong anti‐A alloantibodies. For crossmatching, plasma to RBC pairings were prepared using the GC (n = 446) and AGC (n = 630) tests. Both methods showed compatibilities in 329 and incompatibilities in 102 pairings including all A‐B mismatches. Additionally 15 pairings showed agglutination by the AGC but not GC method. Fourteen incompatibilities outside the expected A‐B mismatches were only revealed by AGC. Conclusions and Clinical Importance AB typing using immunochromatographic strip is as accurate as laboratory flow cytometry. The 2 XM methods had good agreement with additional incompatibilities being recognized by the AGC XM beyond A‐B incompatibilities. In clinic, feline AB typing and sensitive XM test kits are available and recommended before each transfusion, although the clinical implications of incompatible XM test results and clinical benefits of such crossmatching have not been documented.

Objectives The aims of this study were to update the prevalence of different feline blood types in the Lyon (France) area, as well as to determine the risk of mismatched transfusion (MT) and neonatal isoerythrolysis (NI) in kittens with parents of unknown blood type. Methods Blood samples were obtained from blood donor cats and cats admitted to an intensive care unit in Lyon. AB blood typing was performed using an immunochromatographic strip. The risk of MT was estimated by adding the risk of a major transfusion reaction and the risk of a minor transfusion reaction. The risk of NI was estimated according the equation (p²)(q²) + 2pq(q²), with q being the b allele frequency and p = 1 – q. The results were analysed by absolute and relative frequency analysis and multivariate analysis. Results The cohort study population included 320 non-pedigree cats and 37 pedigree cats. The prevalence of blood types A, B and AB was 84.3%, 14.0% and 1.7%, respectively. Considering non-pedigree cats, the prevalence of types A, B and AB was 83.7%, 14.4% and 1.9%, respectively. There were no significant differences of blood type distribution by sex ( P = 0.73) or by breed ( P = 0.90). Based on these percentages, the risks of MT and NI in non-pedigree cats were 24.3% and 12.3%, respectively. Conclusions and relevance The prevalence of type B cats is high in the Lyon area and associated with high risks of MT and NI. These results confirm the importance of performing blood typing prior to any blood transfusion or mating.

ObjectivesTo describe the change in the caudal vena cava to aorta ratio (CVC:Ao) ratio during fluid resuscitation of circulatory shock in dogs and compare these results with those of the physical examination and blood lactate.Materials and MethodsPerfusion parameters and blood lactate were recorded at admission. An abdominal point‐of‐care ultrasound protocol was performed, during which the caudal vena cava to aorta ratio was measured on the spleno‐renal view. Measurements were performed within 5 minutes before and after a 10 mL/kg crystalloid fluid bolus. Investigators were not blinded to therapeutic interventions.ResultsTwenty‐nine dogs with physical signs of circulatory shock were enrolled. Caudal vena cava to aorta ratios were below reference interval in 28 of 29 dogs. After bolus administration, median caudal vena cava diameter increased by 0.14 cm (0.69 to 0.83 cm) and median aorta diameter increased by 0.03 cm (0.87 to 0.90 cm) and caudal vena cava to aorta ratio returned to within reference range in 65% of dogs (13/29). Bolus administration was associated with an increase in median caudal vena cava to aorta ratio of 0.10 (95% CI=0.05 to 0.16, P=0.0005). Blood lactate did not change significantly. Heart rate and capillary refill time decreased significantly after fluid bolus (heart rate: estimate=−19 bpm, 95% CI=−30 to −8, P=0.002; capillary refill time: estimate=−1.0 s, 95% CI=−1.3 to −0.7, P < 0.0001).Clinical SignificanceIn this population of dogs with circulatory shock, the caudal vena cava to aorta ratio significantly increased after a fluid bolus. Future studies that implement blinding of the outcome assessors are warranted to confirm these findings.