The clinical, laboratory, and serological findings in 17 dogs with disease resulting from leptospiral infection were evaluated retrospectively. Acute renal failure was the most common syndrome, but cholestatic hepatic disease also was common. The most prevalent serovars identified were pomona, grippotyphosa, and autumnalis. Paired serology was available on 10 dogs. Aggressive fluid therapy in combination with ampicillin or amoxicillin resulted in a good survival rate. Canine leptospirosis may be more common than suspected, and paired serology often is necessary to confirm a diagnosis.

Irrespective of health status, 8.2% of dogs were shedding pathogenic leptospires. Serologic testing was a poor predictor of urinary shedding. Clinically normal dogs that shed leptospires may pose a zoonotic risk to their owners.

Feline histoplasmosis is a systemic fungal infection often treated with itraconazole, which can be cost-prohibitive for some clients. Additionally, although the clinical disease in cats has been documented, sources of Histoplasma species spore exposure in cats have yet to be thoroughly investigated. The objectives of this study were to compare the outcomes of cats with histoplasmosis treated with fluconazole to those treated with itraconazole, and to evaluate possible sources of exposure for affected cats. Medical records from feline patients with confirmed histoplasmosis (n = 32) at Kansas State University were systematically reviewed and follow-up was performed by owner telephone interview. Cats treated with fluconazole (n = 17) had similar mortality and recrudescence rates when compared with cats treated with itraconazole (n = 13). Thus, fluconazole may be a viable alternative therapy for the treatment of feline histoplasmosis. Eleven cats were housed strictly indoors and possible sources of exposure reported for these cats included potted plants (5/11) and unfinished basements (6/11).

Classes of antibody bound to erythrocytes were determined using direct immunofluorescence (DIF) flow cytometry in 3 horses and 12 dogs with immune-mediated hemolytic anemia (IMHA). Background levels of antibody binding were determined in samples from 12 horses and 12 dogs that were free of clinical disease. The range of nonspecific binding of a fluorescein isothiocyanate (FITC)-conjugated goat anti-equine immunoglobulin G (IgG) was 19.9-36.7%, but was eliminated by the use of the F(abЈ) 2 fragment of FITC-conjugated goat anti-equine IgG. Background binding by other class-specific antibodies to equine and canine erythrocytes was negligible. The DIF results were compared to the direct antiglobulin (Coombs') test in 5 horses and 20 dogs with anemia. The former assay was more sensitive in dogs with IMHA than was the Coombs' test (100% versus 58%). In contrast, the Coombs' test had better specificity than the DIF assay (100% versus 87.5%, respectively). Using clinical parameters or response to therapy as the comparison, the positive and negative predictive values for the DIF test were 92% and 100% compared to the values of the Coombs' test of 100% and 62%. The DIF assay detected low levels of cells bound with antibody (Ͻ30%) in 5 dogs that were Coombs' test-negative. For both species, performance of the DIF test was independent of the prozone effect. Five dogs with IMHA had IgG and IgM on erythrocytes, 5 had IgG, and 2 had IgM. Three horses had surface-bound IgG, including a horse with suspected penicillin-induced IMHA, a foal with neonatal isoerythrolysis, and a foal with clostridial septicemia. The DIF method was valuable in monitoring the response to therapy in the foal with neonatal isoerythrolysis.Key words: Antibody classes; Coombs' test; Direct immunofluorescence; Erythrocyte antibody; Flow cytometry. Immune-mediated hemolytic anemia (IMHA) is an immunohematologic disorder in which destruction of red blood cells is accelerated by the attachment of antibody, with or without complement, to the erythrocyte membrane. Antibodies may be directed against unaltered red blood cells (primary or idiopathic) or against erythrocytes that have been antigenically altered through interaction with secondary causes, including drugs, neoplasia, and infectious diseases.1-6 The relative frequencies of primary and secondary IMHA in dogs are 43% and 57%, respectively. 7The diagnosis is confirmed by the presence of spherocytosis, autoagglutination, or by a positive direct antiglobulin (Coombs') test that has been validated for use in the species of interest. [8][9][10][11][12] The Coombs' test is based on detection of agglutination or clumping of erythrocytes after addition of an anti-species polyvalent mixture of antibody to immunoglobulin M (IgM), IgG, and complement protein C 3 . Serial dilutions of the polyvalent Coombs' reagent are prepared and tested against patient erythrocytes to provide the proper concentration equivalence between antiglobulin and the antibody-coated erythrocytes at which agglutination occurs. Because of the...

Immune-mediated thrombocytopenia (IMT) is a disorder in which bound IgG on the surface of platelets results in platelet removal and alterations in mean platelet volume. Using flow cytometry, alterations in platelet size, platelet surface-associated IgG (PSAIgG), and numbers of reticulated platelets were determined in 13 dogs with primary IMT and 4 dogs with secondary IMT induced by experimental infection with Babesia gibsoni. Effects of sample age on platelet parameters also were determined, using samples from 20 dogs with normal platelet counts analyzed within 4 hours and after 24, 48, and 72 hours of storage in EDTA. No significant changes in platelet count, platelet size, or reticulated platelet percentage were observed in samples assayed within 4 and 24 hours of blood collection; whereas PSAIgG values increased 3 to 7 fold in samples stored for 24-72 hours. Using reference values for freshly collected or 24-hour-old samples, 10 of 13 (77%) dogs with primary IMT and all B gibsoni-infected dogs had increased PSAIgG levels. In 12 (75%) of the 16 dogs with thrombocytopenia the percentage of reticulated platelets was increased; however, absolute numbers of reticulated platelets were within reference values. Moreover, PSAIgG level and the percentage of reticulated platelets were not always increased concurrently in dogs with primary and secondary IMT. Platelet microparticles were detected in all B gibsoni-infected dogs, 8 of 13 (62%) dogs with primary IMT, and transiently in a dog that responded to immunosuppressive treatment. The results of this study indicate that sample age and time of sampling during disease affect interpretation of platelet parameters in dogs with IMT.