A 7-year-old neutered male Cavalier King Charles spaniel is presented after an episode of collapse.
History. The dog was presented to the referring veterinarian after an episode of collapse and weakness at a boarding kennel. The patient had been eating and drinking normally before the collapse episode but had been lethargic. The referring veterinarian noted evidence of hemolytic anemia, which was suspected to be immune-mediated. The dog was referred after initial treatment with vitamin K, gastroprotectants, and IV fluids. An untreated heart murmur was noted on the history.
Physical Examination. On presentation to the referral hospital, the patient had icteric sclera and mucous membranes, a grade 3/6 systolic heart murmur, discomfort on abdominal palpation, nystagmus, and decreased pupillary light responses and mentation.
Laboratory Results. A complete blood count revealed marked neutrophilic leukocytosis with a moderate regenerative left shift, including rare metamyelocytes, toxic change, and monocytosis. Other laboratory findings included a hematocrit of 9%, mild macrocytosis, normal mean corpuscular hemoglobin concentration, increased nucleated red blood cells, and normal platelet count. A review of the blood film revealed 50% to 75% Heinz bodies, numerous spherocytes, and red blood cell ghosts (Figure 1).