Retrospective study on diagnostic yield and medical impact of diagnostic imaging in dogs with immune‐mediated haemolytic anaemia in Belgium

OBJECTIVES: To assess the incidence of associative immune-mediated haemolytic anaemia in dogs diagnosed with immune-mediated haemolytic anaemia and to evaluate whether performing diagnostic imaging, specifically thoracic radiographs and abdominal ultrasound, influences outcomes in non-associative immune-mediated haemolytic anaemia. MATERIALS AND METHODS: Medical records (2017 to 2023) were reviewed for dogs diagnosed with immune-mediated haemolytic anaemia. Dogs were classified as associative immune-mediated haemolytic anaemia or non-associative immune-mediated haemolytic anaemia. Survival odds at 3, 6 and 12 months were assessed for non-associative immune-mediated haemolytic anaemia. Multivariable logistic regression was used to identify factors associated with a risk of decreased survival. RESULTS: Among 117 immune-mediated haemolytic anaemia cases, 7 (6%) had associative immune-mediated haemolytic anaemia, and 110 (94%) had non-associative immune-mediated haemolytic anaemia. In non-associative immune-mediated haemolytic anaemia dogs, thoracic radiographs were performed in 63 dogs (57.3%) and abdominal ultrasound in 90 dogs (81.8%), with unremarkable thoracic radiographs in 55.5% of cases and unremarkable abdominal ultrasound in 17.8%. Diagnostic imaging did not significantly affect the risk of decreased survival at 3, 6 and 12 months (P > .05). Increasing age (OR [95% CI]: 1.31 [1.06 to 1.61] at 12 months), elevated serum alanine aminotransferase (OR [95% CI]: 3.93 [1.11 to 14.0] at 3 months) and a higher number of packed red blood cell transfusions (OR [95% CI]: 2.10 [1.09 to 4.08] at 3 months and 1.91 [1.02 to 3.56] at 6 months) were associated with an increased risk of decreased survival. CLINICAL SIGNIFICANCE: Performing diagnostic imaging was not associated with a change in survival odds in dogs with non-associative immune-mediated haemolytic anaemia in this cohort. These findings suggest individual case-based diagnostic imaging may be appropriate in clinical practice.