Abbe Harper Crawford

An 8‐month‐old, female toy poodle and a 5‐year‐3‐month‐old, male, neutered Bernese Mountain dog presented with acute onset, progressive neurological deficits. Neurological examination findings were consistent with multifocal forebrain, brainstem and potential C1–C5 spinal cord segment involvement in both dogs. The toy poodle had a packed cell volume of 85% on presentation, and rapidly deteriorated to cardiopulmonary arrest. Postmortem examination revealed multifocal leptomeningeal, white and grey matter haemorrhage. Femoral bone marrow analysis revealed 95%:5% haematopoietic:fat ratio (reference value: 80%:20%). The Bernese Mountain dog had an initial packed cell volume of 81%. Magnetic resonance imaging of the head identified multifocal cerebral haemorrhage. The erythrocytosis was believed to be secondary to marked bilateral nephropathy. Following two phlebotomies, the packed cell volume decreased to 78%. However, the dog deteriorated and had a cardiopulmonary arrest. We report two clinical cases in which erythrocytosis was the cause of rapid and severe neurological deterioration.