An 11 year old female-neutered Labrador presented for facial swelling. Clinicopathological abnormalities included hyperglobulinemia, azotemia, hypercalcemia, nonregenerative anemia, thrombocytopenia, and spurious hypoglycemia. Normoglycemia was subsequently confirmed using a cage-side analyzer (AlphaTRAK, Zoetis, UK). Serum and urine protein electrophoresis documented monoclonal (immunoglobulin M) gammopathy with Bence-Jones proteinuria. Computed tomography imaging revealed a monostotic osteolytic bone-lesion, and bone marrow cytology and histopathology documented plasmacytosis with multiple myeloma oncogene 1 / interferon regulatory factor 4 positivity, consistent with multiple myeloma. Infectious disease testing initially indicated seropositivity for Leishmania, Borrelia, and Anaplasma spp.; however, Leishmania PCR (splenic and bone marrow aspirates), and paired serological titers for Borrelia and Anaplasma were negative. Consequently, initial serological results were considered to be false positive because of paraproteinemia-associated assay interference. Chemotherapy (prednisolone and melphalan combination therapy) was initiated, but the dog was euthanased 30 days later because of the development of pericardial effusion. This is a report of spurious serological (and other laboratory) results occurring secondary to monoclonal gammopathy in a dog.

Background Canine stomatocytosis is a well‐recognized rare erythrocyte disorder characterized by nonsyndromic forms with selective erythroid involvement, syndromic forms with extra‐hematologic disease, and acquired forms. Objectives We describe serial clinicopathologic changes in two dogs with stomatocytosis of breeds that are different from those previously reported. Methods Blood samples were obtained from a 12‐year‐old female neutered Australian Cattle Dog and a 12‐year‐old male neutered Beagle for hematologic and biochemical analyses, including a morphologic examination of peripheral blood films. Serial clinicopathologic data were reviewed, including CBCs performed by the referring veterinary surgeons. Results Serial CBC data in both cases reported a variable decrease in RBC numbers commonly associated with a normal hematocrit, macrocytosis, hypochromasia, changes in red cell distribution width parameters including marked histogram abnormalities in volume distribution of the RBC population, and mildly increased or normal reticulocyte counts. Morphologic examination of peripheral blood films identified variable numbers of stomatocytes, knizocytes (Case 1, Day 1, Day 4), mild anisocytosis, mild macrocytosis, and mild polychromasia. Conclusions In both cases, the changes exhibited in the erythrogram raise suspicion for an RBC membrane disorder with cell volume dysregulation and stomatocytosis, although they did not appear to cause clinically relevant hemolysis.

Background The cytologic diagnosis of inflammation on canine hepatic aspirates can be confounded by neutrophilic infiltrates in the liver of dogs with nodular regeneration, by extramedullary hematopoiesis, and by marked blood contamination. Objectives We aimed to assess the association between neutrophil counts on hepatic cytology and the histopathologic diagnosis in dogs with hepatitis and non‐inflammatory hepatopathy. We also sought to determine a cut‐off value for the cytologic diagnosis of hepatitis. Methods In a retrospective blinded pilot study, three observers independently reviewed hepatic aspirates that had corresponding histopathologic examinations performed within 2 days. The number of neutrophils per 200 hepatocytes was determined and averaged among observers. Only neutrophils within or directly in contact with a cluster of ≥5 hepatocytes were counted, and only intact hepatocytes within an approximate monolayer were included. Data are presented as the median (range), and the Mann‐Whitney U test is used to make comparisons between groups. Results Eighteen cases were included (13 hepatitis and five vacuolar hepatopathy). Aspirates with a histopathologic diagnosis of hepatitis had increased numbers of neutrophils compared with those of vacuolar hepatopathy (7.7 [0.3‐18.3] vs 3.0 [1.0‐5.3]; P = .038). Receiver operating characteristic curve analysis indicated that ≥6 neutrophils were 61.5% (CI 31.6%‐86.1%) sensitive and 100% (CI 47.8%‐100%) specific for identifying hepatitis. Conclusions Liver aspirates from hepatitis cases have a higher number of neutrophils on cytology compared with those from vacuolar hepatopathy; however, larger studies, including those with dogs with other liver pathologies, are required. Identification of six or more neutrophils per 200 hepatocytes is highly suggestive of hepatitis.