Immunoreactivity of canine, feline, and equine D-dimer with antibodies to human D-dimer.

BACKGROUND: Commercially available D-dimer assays use antibodies against human D-dimer, with limited sensitivity and specificity data in companion animals. OBJECTIVES: To evaluate the immunoreactivity of D-dimer in plasma of dogs, horses, and cats with commercially available antibodies to human D-dimer. ANIMALS: Plasma samples were collected from healthy dogs and horses, and from surplus feline plasma submitted for diagnostic purposes. METHODS: Descriptive research study. A cross-linked fibrin lysate was prepared from plasma samples, and SDS-PAGE and immunoblotting were performed with a variety of commercially available antibodies to human D-dimer. RESULTS: The selected antibodies demonstrated variable reactivity with D-dimer of each species. The monoclonal antibody DD44 bound canine D-dimer with good specificity and sensitivity, but this antibody did not react with feline or equine D-dimer. The polyclonal antibody D2D bound putative D-dimer in dogs, cats, and horses with good specificity, and higher sensitivity compared to human D-dimer. CONCLUSIONS AND CLINICAL IMPORTANCE: The variable performance of commercially available human D-dimer assays between species is, in part, because of inter-species variation in D-dimer immunoreactivity. The use of these assays should follow validation studies. Monoclonal antibody DD44 could be a focus for the development of a canine-specific assay.

Analytical errors in nucleated red blood cell enumeration.

BACKGROUND: Enumeration of nucleated red blood cells (NRBCs) in peripheral blood of dogs and cats is performed by manual counting during blood film evaluation. Automated methods have increased precision and accuracy; however, most analyzers cannot distinguish leukocytes and NRBCs. The Sysmex XN-V Series may distinguish NRBCs and leukocytes; however, analytical errors occur. OBJECTIVES: We aimed to investigate cases with discrepant automated and manual NRBC counts, and to evaluate reasons for analytical errors. METHODS: Data from samples with increased NRBCs were collected retrospectively and compared with manual counts performed on blood films using Spearman's correlation, Passing-Bablok agreement analysis, and Bland-Altman comparisons. Precision of the automated method and interobserver agreement of manual counts were evaluated. Cases with discrepant results were investigated. RESULTS: Agreement between the methods was good at ≤1NRBC ×109 /L in dogs and cats, and inadequate at ≥1NRBC ×109 /L. The automated method demonstrated a negative proportional difference to the manual method. Precision was good for the automated method (overall CV 7.1%) and interobserver agreement for the manual method was poor overall (mean CV 27.3%, range 0%-106.1%). Inaccuracies in NRBC enumeration by the automated method occurred with high hematocrits, the mergence of the cell fragments and leukocyte clouds, and the presence of earlier erythroid precursors. CONCLUSIONS: NRBC enumeration by the WNR channel on the Sysmex XN-1000 V is precise and has good agreement with manual counts in canine and feline blood samples at ≤1NRBC ×109 /L. Manual film review is indicated for samples with ≥1NRBC ×109 /L, earlier erythroid precursors, samples from greyhounds and dehydrated patients, and if gating errors are noted.

Hypoglobulinemia in a dog with disseminated plasma cell neoplasia: Case report and review of the diagnostic criteria.

This is the first reported case of hypoglobulinemia in a dog with disseminated plasma cell neoplasia. A 6-year-old male intact Rottweiler was referred to the U-Vet Animal Hospital (Werribee, Vic, Australia) for weight loss, hyporexia, lethargy, vomiting, and soft stools. Examination of a buffy coat preparation and splenic and liver aspirates revealed a monomorphic population of plasmacytoid cells, and the same cells comprised approximately 90% of bone marrow samples submitted for cytologic and histologic evaluation. Biochemistry revealed a hypoglobulinemia, and the presence of an M-protein was not supported by serum and urine protein electrophoresis or serum immunofixation. Immunohistochemistry demonstrated strong nuclear labeling for MUM-1.

Biochemistry and hematology reference intervals for neonatal dairy calves aged 5-12 days.

BACKGROUND: Comprehensive hematology and biochemistry RIs are currently lacking in the literature for young dairy calves based on sample sizes more than 120. Young dairy calves are at a relatively high risk of poor health and welfare outcomes. They have a high risk of morbidity and mortality in the first 2 weeks of life, and many are transported and fasted during this time. For example, non-replacement calves in Australia and New Zealand are usually 5-12 days old when transported to abattoirs, meaning that calves of this age group are potentially at risk of both health and welfare compromise. Given these factors, sound, comprehensive, age-specific biochemical and hematologic RIs are needed for both veterinary clinical practice and to inform research on calf health and welfare. OBJECTIVES: The aim of this study was to generate age-specific hematology and biochemistry RIs for dairy calves aged 5-12 days. METHODS: We collected blood samples from 141 fasted, healthy dairy calves on 10 Australian farms. Reference Value Advisor software was used to calculate nonparametric RIs for multiple biochemistry and hematology variables. RESULTS: RIs for a panel of hematology and biochemistry variables in dairy calves aged 5-12 days old were derived. CONCLUSIONS: These RIs will be useful for clinical veterinary practice, as well as for research on dairy calf health and welfare.

Fibrinogen heterogeneity in horses.

BACKGROUND: Fibrinogen heterogeneity has been observed in humans and can influence fibrinogen measurements when using the modified Clauss assay. We hypothesized that fibrinogen heterogeneity also exists in horses. OBJECTIVES: To determine whether fibrinogen heterogeneity exists in horses. ANIMALS: Five clinically healthy horses from the university equine teaching herd. METHODS: Presumed fibrinogen was purified from pooled citrated plasma and electrophoresis performed. The purified protein was subjected to Western blotting using sheep antiserum against human fibrinogen, and liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: Gel electrophoresis of nonreduced equine purified protein yielded 2 protein bands (approximately 377 and 318 kDa) that corresponded with the molecular weights of human high molecular weight fibrinogen and low molecular weight fibrinogen fractions, respectively. Electrophoretograms of reduced purified protein, Western blots, and LC-MS/MS supported that the purified nonreduced protein bands were fibrinogen. CONCLUSION: Fibrinogen heterogeneity exists in horses.

Unique cytologic and histologic features of a suspected cutaneous xanthoma in a dog.

A 4-year-old spayed female American Staffordshire Terrier presented to the U-Vet Animal Hospital, Werribee, Australia, with a cutaneous mass that had been slowly growing over 12 months. Cytologic evaluation showed cohesive to individualized, vacuolated spindled cells often arranged in a perivascular pattern. The mass was completely excised, and the histopathologic examination demonstrated sheets of vacuolated spindled to round cells expanding the full thickness of the dermis. The cells demonstrated both Iba1 and CD18 antibody binding, leading to an initial interpretation of histiocytic sarcoma. Given the discordance with the clinical presentation, further immunohistochemistry (IHC) was performed. The cells demonstrated strong CD204 antibody binding and did not bind E-cadherin antibody, consistent with a dermal macrophage origin. Ki-67 antibody binding was regionally variable from <5% to 25%, with more regions that had low Ki-67 expression. A fasted serum biochemistry panel revealed hypertriglyceridemia and persistent hypercholesterolemia. Based on clinical, microscopic, biochemical, and IHC results, the final interpretation was an indolent dermal histiocytic proliferation of macrophage origin, with a preference for cutaneous xanthoma or reactive dermal fibrohistiocytoma.

Septic peritonitis in a dog caused by Anaerobiospirillum succiniproducens.

This is the first reported case of septic peritonitis caused by Anaerobiospirillum succiniproducens in a dog. The infection was associated with marked exfoliation of reactive mesothelial cells into the abdominal fluid mimicking neoplasia. The source of the infection was not determined but was presumed to be of gastrointestinal origin as A succiniproducens is part of the normal gastrointestinal flora of dogs. Anaerobiospirillum spp. have been previously reported as causing diarrhea and bacteremia in people, particularly if immunocompromised; however, there were no indicators for a compromised immune system in this dog.