Search

Coagulopathy is common in equine critical illness, with its early recognition being crucial for patient management and prognosis. In vitro viscoelastic (VE) hypercoagulability with decreased RCM/PCV has been demonstrated in dogs but not horses. Our objective was to evaluate the effects of acepromazine-induced (0.1 mg/kg IV) decreased RCM on VE and plasma coagulation parameters using a prospective interventional study of eight adult horses. Complete blood count (CBC), fibrinogen, prothrombin time (PT), partial thromboplastin time (PTT), packed cell volume (PCV), total solids (TS), and VCM Vet™ VE testing performed at baseline (T0), 1 h (T1), and 12 h (T2) post acepromazine administration. Splenic volume was determined ultrasonographically. The results were analyzed using one-way repeated measures ANOVA with Tukey's post hoc HSD test to determine the effect of time (sample). PCV decreased 13% points following acepromazine administration from T0 to T1 ( p < 0.001), remaining decreased at T2 ( p < 0.001). Splenic volume increased from T0 to T1 ( p = 0.04) and was not different from baseline at T2. Maximal clot formation (MCF) increased from T0 ( p = 0.03). PTT decreased from T0 to T1 and increased at T2 ( p = 0.03). No other coagulation parameters were significantly altered. This study demonstrates a non-inflammatory acute model of anemia in horses that impacts VE and plasma-based testing.

Objectives: The objectives of this study were to describe the clinical features of cats diagnosed with tularemia, and to compare the clinical features of cats with and without tularemia and identify characteristics increasing the likelihood of a tularemia diagnosis., Methods: Diagnostic laboratory data and medical records were retrospectively reviewed of cats tested for tularemia between 2000 and 2021. Clinical features including signalment, presenting complaint(s), physical examination findings and clinicopathologic data were described for cats with tularemia diagnosed by culture and/or PCR. Clinical features were also compared between PCR+ vs PCR- cats and logistic regression was used to identify features that predicted PCR+ status., Results: A total of 18 cats were diagnosed with tularemia. The affected cats had a mean age of 5.8 ± 4.9 years, with a slight male predominance. Most were domestic shorthair cats and had outdoor access. Common presenting complaints included lethargy and anorexia, while physical examination findings frequently revealed fever, peripheral lymphadenomegaly and oral ulcers. Laboratory findings varied, with notable abnormalities including neutrophilic inflammation observed on cytology and widespread acute systemic pathologic changes in necropsy results. Leukopenia and neutropenia were more common in PCR+ vs PCR- cats, and these factors were 7.4 times (confidence interval [CI] 1.2-62.3) and 10.0 times (CI 1.4-83.2) more likely to occur in PCR+ vs PCR- cats, respectively. There were no significant differences between the groups in other parameters including anemia, thrombocytopenia, band neutrophilia and hyperbilirubinemia., Conclusions and Relevance: This study provides a more comprehensive description of tularemia in cats than has been available to date. In particular, leukopenia and neutropenia are significantly associated with tularemia-positive cats. These clinical features should be considered and raise suspicion for tularemia in cats. These findings may be valuable for the timely diagnosis, treatment and prevention of tularemia outbreaks in cats and humans., Competing Interests: Conflict of interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Acute phase protein (APP) measurement is used to detect inflammation. Intramuscular (IM) injections could cause tissue injury and induce an acute phase response (APR)., Objectives: To evaluate the effects of IM procaine penicillin G (PPG) injections on APP concentrations in horses., Study Design: Prospective longitudinal design., Methods: PPG was administered intramuscularly to six horses, twice daily, for 5 days. Plasma fibrinogen (FIB), serum amyloid A (SAA), haptoglobin (HAP), creatine kinase (CK), and aspartate aminotransferase (AST) were quantified daily for 5 days before the first injection, during the course of administration, and for 4 days after the final dose. Analytes were quantified every other day for the remaining 16 days. Data were compared using a parametric or non-parametric repeated measures ANOVA and a Tukey's or Mann-Whitney rank sum test, respectively. Significance was set at p < 0.05., Results: CK was increased over baseline (mean ± SD: 200 ± 74 IU/L) on Days 1-6 (p < 0.001 to p = 0.02, mean ± SD: 723-1177 ± 355-544 IU/L) and AST was increased above baseline (mean ± SD: 233 ± 58 IU/L) on Days 2-7 and 10 (p < 0.001 to p = 0.05, mean ± SD: 307-437 ± 79-146 IU/L). Increased FIB was noted over baseline (mean ± SD: 177 ± 30 mg/dl) on Days 6-8 and 10 (p = 0.02 to p = 0.03, mean ± SD: 234-252 ± 33-49 mg/dl). SAA was increased above baseline (mean ± SD: 4.7 ± 2.9) on Day 6 (p = 0.02, mean ± SD: 113 ± 186 μg/ml). There was no change in HAP., Main Limitations: Healthy horses were used, small sample size, and a lack of a negative control group., Conclusions: Serial intramuscular procaine penicillin G (IM PPG) injections may result in increased positive APP concentrations in horses and this must be considered when these test results are interpreted., (© 2022 The Authors. Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.)

Objectives: Determine the effect of sample holding time and single sample reuse on viscoelastic coagulation parameters when using fresh equine native whole blood., Animals: 8 healthy adult horses from a university teaching herd., Procedures: Blood collected by direct jugular venipuncture (18 ga needle, 3 mL syringe) was held at 37 °C for 2, 4, 6, or 8 minutes according to 1 of 2 protocols. Syringes were gently inverted twice, a small amount of blood was expressed, testing cartridges were filled, and placed within the VCM-Vet™ device (Entegrion Inc). Protocol A: samples were processed from a single syringe. Protocol B: 4 syringes were drawn through a single needle. VCM-Vet™ measures assessed included clot time (CT), clot formation time (CFT), alpha angle (AA), amplitude at 10/20 minutes (A10/A20), maximal clot firmness (MCF), and lysis index at 30/45 minutes (LI30/LI45). Differences over time were examined using the Friedman test and post hoc Wilcoxon Rank Sum Test with Bonferroni correction, P ≤ .05., Results: Following Protocol A, there was a significant effect of holding time for CT (P = .02), CFT (P = .04), and AA (P = .05). CT and AA decreased over time, while CFT increased. Samples handled by Protocol B showed no significant difference over time for any of the VCM-Vet™ parameters., Clinical Relevance: Sample holding time and handling protocol impact VCM-Vet™ testing results of fresh equine native whole blood. Viscoelastic coagulation samples tested using the VCM-Vet™ may be held unagitated for up to 8 minutes after collection while warm, but should not be reused.

Background: The diagnosis of neoplastic cavitary effusions requires the identification of neoplastic cells in effusions, yet the cytologic appearance of neoplastic effusions can be highly variable due to the varied mechanisms of formation. Additional parameters might aid in the interpretation of equivocal cytologic results., Objectives: Our goal was to evaluate whether total protein concentrations can be used to support the diagnosis of neoplasia in the peritoneal and pleural effusions of dogs with lower cellularities (≤5000 nucleated cells/μL)., Methods: Pleural and peritoneal fluid analyses from dogs presented to the University of Illinois Veterinary Teaching Hospital between 2014 and 2019 were evaluated retrospectively. Effusions were categorized as neoplastic or non-neoplastic based on histology or cytology. Non-neoplastic effusions were subcategorized according to mechanism: decreased oncotic pressure, increased hydrostatic pressure, increased vascular permeability, leakage of urine, and leakage of lymph. The TP and blood albumin to fluid TP ratio (Alb blood :TP fluid ) were compared among groups., Results: Twenty-seven neoplastic and 65 non-neoplastic cases were evaluated. TP was higher in the neoplastic group (P = .001) than in the non-neoplastic group. Neoplastic effusions had a lower Alb blood :TP fluid than non-neoplastic (P = .001), and effusions with Alb blood :TP fluid of ≤0.6 were 5.6 times more likely to be neoplastic (95% CI 1.69-17.36; P = .003)., Conclusions: Fluid TP concentrations were significantly greater in neoplastic than non-neoplastic effusions; however, given the considerable overlap between groups, the diagnostic utility of this difference is low. A neoplastic etiology might be more likely in cases with an Alb blood :TP fluid ≤0.6., (© 2022 American Society for Veterinary Clinical Pathology.)

Developing effective therapies for the treatment of advanced head-and-neck squamous cell carcinoma (HNSCC) remains a major challenge, and there is a limited landscape of effective targeted therapies on the horizon. NAD(P)H:quinone oxidoreductase 1 (NQO1) is a 2-electron reductase that is overexpressed in HNSCC and presents as a promising target for the treatment of HNSCC. Current NQO1-targeted drugs are hindered by their poor oxidative tolerability in human patients, underscoring a need for better preclinical screening for oxidative toxicities for NQO1-bioactivated small molecules. Herein, we describe our work to include felines and feline oral squamous cell carcinoma (FOSCC) patients in the preclinical assessment process to prioritize lead compounds with increased tolerability and efficacy prior to full human translation. Specifically, our data demonstrate that IB-DNQ, an NQO1-targeted small molecule, is well-tolerated in FOSCC patients and shows promising initial efficacy against FOSCC tumors in proof-of-concept single agent and radiotherapy combination cohorts. Furthermore, FOSCC tumors are amenable to evaluating a variety of target-inducible couplet hypotheses, evidenced herein with modulation of NQO1 levels with palliative radiotherapy. The use of felines and their naturally-occurring tumors provide an intriguing, often underutilized tool for preclinical drug development for NQO1-targeted approaches and has broader applications for the evaluation of other anticancer strategies., (Copyright © 2021. Published by Elsevier Inc.)

Background: Analysis of cerebrospinal fluid CK (CSF-CK) might be useful as a prognostic indicator in dogs with neurologic disease. Previous studies have mostly analyzed CSF-CK collected from the cerebellomedullary (CM) cisterna, but CSF collection sites could affect its levels., Objectives: This is a pilot study aimed to evaluate differences in CSF-CK concentrations when collected from the CM or lumbar cisterna in dogs presenting with neurologic disease., Methods: Ten dogs presenting for neurologic disease underwent magnetic resonance imaging and CSF collection from both the CM and lumbar cisterna. Cerebrospinal fluid CK was analyzed within 30 minutes., Results: Ten dogs were prospectively recruited. Overall, there was no statistically significant difference between CSF-CK collected from the CM or lumbar cisterna (P = .31). When evaluated by neurolocalization, CSF-CK was different between sites in dogs with thoracolumbar myelopathy (P = .024), but not in dogs with intracranial or cervical neurolocalization (P = .93). All dogs with thoracolumbar myelopathy had equivocal or higher CK levels at the lumbar collection site compared with levels at the CM collection site., Conclusions: Cerebrospinal fluid CK values differed depending on the CSF site collection, especially in dogs with thoracolumbar myelopathy. In dogs with thoracolumbar myelopathy, CSF-CK was likely to be higher when CSF was taken from the lumbar cisterna compared with the CM cisterna. Collecting CSF from the thoracolumbar site could provide better prognostic information than if collected at the CM collection site., (© 2020 American Society for Veterinary Clinical Pathology.)

Background: Cerebrospinal fluid (CSF) analysis aids in categorizing underlying disease processes in patients with neurologic disease. Convention suggests that CSF should be collected caudal to the lesion. However, little evidence exists to justify this assertion., Hypothesis/objectives: Evaluate the clinicopathologic differences between CSF collected from the cerebellomedullary (CM) and lumbar cisterns in dogs presented for evaluation of neurologic disease., Animals: Fifty-one client-owned dogs undergoing magnetic resonance imaging (MRI) and CSF collection for investigation of neurologic disease., Methods: Cerebrospinal fluid was prospectively collected from the CM and lumbar cisterns in all patients. The total protein (TP) concentration, red blood cell (RBC) count, and total nucleated cell count (TNCC) were analyzed within 30 minutes of collection. Results and cytology findings were interpreted by a single pathologist., Results: Fifty-one paired samples were collected. The TNCC (P < .001), RBC (P < .001), and TP (P < .001) were different between collection sites. When grouped by neurolocalization, TP (intracranial, P < .001; cervical, P < .001; thoracolumbar, P < .001) and RBC (intracranial, P < .001; cervical, P ≤ .002; thoracolumbar, P = .006) counts were significantly different. The TNCC was significantly different in the cervical (P = .04) and thoracolumbar localizations (P = .004) but not for intracranial (P = .30) localizations. The pathologist's interpretation differed between sites in 66.7% of the cases (34/51)., Conclusions: In dogs with lesions that neurolocalized to the brain or cervical spinal cord, there may be clinical benefit in collecting fluid from both the CM and lumbar cisterns. In dogs with thoracolumbar myelopathy, CSF collected from the CM cistern may not be representative of the underlying disease process., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

The landscape composition of an organism's home range or territory should influence aspects of its condition, including measures of immune function. Changes in immunocompetence arising from variation in landcover may provide important links between habitat changes and patterns of disease spread. To establish a baseline understanding for whether immune measures covary with changes in landcover, we examined associations between immunological parameters and landcover composition for adults and nestlings of five shrubland bird species. Specifically, we examined the bacteria-killing ability (BKA) of the blood plasma and profiles of the five avian leukocytes as our measures of immune function, and assessed the proportion of area around each bird's nest that was composed of the four major landcover types in the Midwestern USA: row crop agriculture, developed, forest, and grass/shrub. We performed landcover assessments at 100 and 1000 m radius buffers to identify whether associations between habitat and immune function differed at the two spatial scales. As part of this work, we examined age and species-related immunological variation, as well as associations among the immune parameters. There was little evidence linking variation in immune function to landcover composition for the adults at either spatial scale, but there were numerous associations for nestlings, and these were stronger at the 1000 than 100 m spatial scale. The proportion of grass/shrub around the nest had the largest impact on immune function, although the effect varied by immune parameter and species. BKA and basophils were inversely associated with grass/shrub for all species, whereas lymphocytes were positively associated with grass/shrub for all species. We also documented species-level differences among adults and nestlings for BKA and all leukocytes except monocytes. As expected, we found that nestlings had reduced levels of BKA, lymphocytes, monocytes, and elevated heterophils compared with adults (except for field sparrow-Spizella pusilla-nestlings, which had higher lymphocytes). Basophils generally did not differ by age class, and eosinophils exhibited species-specific patterns, in which they were higher for nestling American robins (Turdus migratorius) and gray catbirds (Dumetella carolinensis) compared with adults, but lower in the other nestlings. Heterophils and lymphocytes were inversely associated for all species and age classes, and basophil levels were positively associated with BKA across species and age classes. Together, these findings bolster our understanding of age and species-specific variation in immune function, and provide evidence that immune measures can covary with changes in landcover., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.)

Background: Canine hemangiosarcoma (cHSA) is a highly metastatic mesenchymal cancer that disseminates by hematogenous and direct implantation routes. Therapies for cHSA are generally ineffective, in part due to advanced clinical disease stage at the time of diagnosis. The validation of conventional molecular methods for detecting novel biomarkers preferentially expressed by cHSA could lead to more timely diagnosis, earlier therapeutic interventions, and improved outcomes. In humans, prostate-specific membrane antigen (PSMA) is a transmembrane protein overexpressed by prostate carcinoma and tumor-associated endothelium of various solid cancer histologies. Importantly, the preferential overexpression of PSMA by certain cancers has been leveraged for the development of diagnostic molecular imaging reagents and targeted therapeutics. Recently, PSMA has been qualitatively demonstrated to be expressed in cHSA cell lines, however, quantitative PSMA expressions and the potential utility of PSMA transcript identification in biologic fluids to support the presence of microscopic cHSA burden has not been reported. Therefore, this study sought to characterize the differential quantitative expressions of PSMA between cHSA and non-malignant tissues, and to determine the potential diagnostic utility of PCR-generated PSMA amplicons as a surrogate of rare cHSA cells dwelling within peritoneal and pericardial cavities., Methods: Quantitative gene and protein expressions for PSMA were compared between one normal endothelial and six cHSA cell lines by RT-PCR, western blot analysis, and fluorescent microscopy. Additionally, gene and protein expressions of PSMA in normal canine tissues were characterized. Graded expressions of PSMA were determined in spontaneously-arising cHSA tumor samples and the feasibility of qualitative PCR as a molecular diagnostic to detect PSMA transcripts in whole blood from healthy dogs and hemorrhagic effusions from cHSA-bearing dogs were evaluated., Results: PSMA gene and protein expressions were elevated (up to 6-fold) in cHSA cells compared with non-malignant endothelium. By immunohistochemistry, protein expressions of PSMA were detectable in all cHSA tissue samples evaluated. As predicted by human protein atlas data, PSMA's expression was comparably identified at substantial levels in select normal canine tissues including kidney, liver, and intestine. In young healthy pet dogs, PSMA amplicons could not be identified in circulating whole blood yet were detectable in hemorrhagic effusions collected from pet dogs with confirmed cHSA or PSMA-expressing cancer., Conclusions: PSMA is quantitatively overexpressed in cHSA compared to normal endothelium, but its protein expression is not restricted to only cHSA tumor tissues, as specific visceral organs also substantively express PSMA. Optimized qualitative PCR methods failed to amplify PSMA amplicons sufficiently for visible detection in circulating whole blood derived from healthy young dogs, yet PSMA transcripts were readily identifiable in hemorrhagic effusions collected from pet dogs with histologically confirmed cHSA or PSMA-expressing cancer. While preliminary, findings derived from a limited cohort of normal and diseased pet dogs provocatively raise the potential value of PSMA amplicon detection as an ancillary molecular diagnostic test for supporting the presence of microscopic cHSA disease burden within hemorrhagic body cavity effusions., Competing Interests: The authors have declared that no competing interests exist.

Cytology of bone is a useful diagnostic tool. Aspiration of lytic or proliferative lesions can assist with the diagnosis of inflammatory or neoplastic processes. Bacterial, fungal, and protozoal organisms can result in significant osteomyelitis, and these organisms can be identified on cytology. Neoplasms of bone including primary bone tumors such as osteosarcoma, chondrosarcoma, fibrosarcoma, synovial cell sarcoma, and histiocytic sarcoma and tumors of bone marrow including plasma cell neoplasia and lymphoma and metastatic neoplasia can result in significant bone lysis or proliferation and can be diagnosed effectively with cytology., (Copyright © 2016 Elsevier Inc. All rights reserved.)

A 5-yr-old, intact male red ruffed lemur ( Varecia rubra ) presented for evaluation as the result of a 1-wk history of lethargy and hyporexia. Physical examination findings included thin body condition, muffled heart sounds, harsh lung sounds, and liquid brown diarrhea. Complete blood count and serum biochemistry showed an inflammatory leukogram, mild hyponatremia, and mild hypochloremia. Orthogonal trunk radiographs revealed a severe alveolar pattern in the right cranial lung lobes with cardiac silhouette effacement. Thoracic ultrasound confirmed a large, hypoechoic mass in the right lung lobes. Fine-needle aspiration of the lung mass and cytology revealed fungal yeast organisms, consistent with Blastomyces dermatitidis. Blastomyces Quantitative EIA Test on urine was positive. Postmortem examination confirmed systemic blastomycosis involving the lung, tracheobronchial lymph nodes, spleen, kidney, liver, cerebrum, and eye. To the authors' knowledge, this is the first report of blastomycosis in a prosimian species.

Objectives: The objective of this study was to document Cytauxzoon felis infection in domestic cats from southern Illinois., Methods: Diagnosis of cytauxzoonosis was based upon clinical signs of illness and detection of piroplasms within erythrocytes on peripheral blood smears or schizonts in internal organs consistent with Cytauxzoon infection. Additionally, genomic DNA was extracted from histologic sections of splenic tissue from two cats., Results: The internal transcribed spacer region-1 (ITS-1) and ITS-2 of the C felis genome were successfully sequenced, confirming infection with the organism., Conclusions and Relevance: Sequence analysis of C felis DNA isolated from histologic lesions in two domestic cats from southern Illinois show either mixed infection or possible heterozygosity (cytosine and thymine) in ITS-2 at the position equivalent to nucleotide 76 (thymine) in the most commonly isolated C felis ITS-2 sequence. Identification of C felis infection in domestic cats from southern Illinois is a critical finding that raises awareness of this often fatal disease process in an area of the USA where, previously, the disease was only anecdotally reported., (© ISFM and AAFP 2015.)

Background: Oxidative stress inhibits albumin's ability to complex with cobalt. Feline serum-cobalt binding has not been described., Objectives: The objective was to develop a cobalt binding test for use with feline serum, and correlate the results with other biochemical and cellular constituents in blood, and with clinical diseases of cats., Methods: A colorimetric test of cobalt binding, based on the oxidation-reduction reaction of Co(+2) and dithiothreitol, was developed using feline serum. The test was used to measure cobalt binding in stored serum from 176 cats presented to the University of Illinois Veterinary Teaching Hospital for a variety of disease conditions. Time-matched hematology and biochemical data, and clinical information, were obtained from the medical record of each cat and correlated with the serum-cobalt binding results., Results: Serial dilution of feline serum with phosphate-buffered saline resulted in a highly linear decrease in serum-cobalt binding (r(2)  = .9984). Serum-cobalt binding of the clinical samples also correlated with albumin concentrations in a stepwise linear regression model (r(2)  = .425), and both cobalt binding and albumin were significantly decreased in cases of inflammation. Albumin and cobalt binding also shared significant correlations with several erythron variables, and serum concentration of total calcium and bilirubin., Conclusions: The correlation of cobalt binding measured by a colorimetric test with albumin concentration in the clinical samples and with serum dilution is consistent with feline albumin-cobalt complex formation. Hypoalbuminemia is the likely cause of reduced serum-cobalt binding in inflammation and the correlations observed between cobalt binding and other variables., (© 2015 American Society for Veterinary Clinical Pathology.)

Vaginal exfoliative cytology is commonly used in biomedical and toxicological research to classify the stages of the rodent estrous cycle. However, mouse vaginal exfoliative cytology is commonly used as a stand-alone tool and has not been evaluated in reference to vaginal histology and serum sex hormone levels. In this study, the direct and Giemsa-stained methods of vaginal exfoliative cytology were compared in reference to vaginal fold histology and serum sex hormone levels. Both methods predicted the estrous stages similarly with mean discordance rates of 55%, 77%, 46%, and 31%, for diestrus, proestrus, estrus, and metestrus, respectively. From these results, we conclude that vaginal exfoliative cytology may be used as a general guide to determine the desired estrous stage end point and that a definitive confirmation of the estrous stage should be obtained from evaluation of vaginal fold histology. Confirmation of the stage of the estrous cycle by vaginal fold histology will decrease the variability otherwise introduced by misclassification of estrous cycle stages with vaginal exfoliative cytology., (© 2014 by The Author(s).)

A young adult feral cat presented to the Champaign County Humane Society with a subcutaneous mass near the stifle. The mass was aspirated. Chains of paired cocci organisms were identified, consistent with Dermatophilus congolensis. The identity of these organisms was confirmed by culture and polymerase chain reaction., (© ISFM and AAFP 2014.)

Background: Erythrophagia has been identified in multiple types of tumors in human medicine, but information in veterinary medicine is limited. In dogs and cats, erythrophagia has been reported to occur in mast cell and plasma cell tumors, lymphoma, megakaryocytic leukemia, and hemophagocytic histiocytic sarcoma. On the basis of clinical experience, we believed this to be an incomplete list that might bias veterinarians toward a diagnosis of histiocytic sarcoma when erythrophagia is observed in neoplastic spindle-shaped cells., Objective: The objective of this retrospective study was to identify neoplasms in dogs that exhibit erythrophagia within the neoplastic cell population., Methods: Reports of cytologic samples collected from dogs and submitted to the University of Illinois Veterinary Diagnostic Laboratory between January 2003 and May 2011 were searched for a description of erythrophagia. Only cases with a diagnosis confirmed by histopathologic examination using immunohistochemical analysis or by cytochemical staining were included. Slides were reviewed by one pathologist to confirm the presence of erythrophagocytic neoplastic cells., Results: Of 20,016 reports searched, 897 contained the term "erythrophagia." In 55 reports, neoplastic cells exhibiting erythrophagia were identified. Of these, 21 cases were excluded because the cytologic diagnosis was not confirmed, and the remaining 34 cases included 12 hemangiosarcomas, 11 hemophagocytic histiocytic sarcomas, 9 osteosarcomas, one mast cell tumor, and one T-cell lymphoma., Conclusion: Erythrophagia can be found in many tumor types. When erythrophagia is observed in spindle-cell sarcomas, osteosarcoma and hemangiosarcoma should be considered in addition to hemophagocytic histiocytic sarcoma., (© 2012 American Society for Veterinary Clinical Pathology.)

Background: Cathepsin K (CatK) is a lysosomal protease with collagenolytic activity, and its secretion by osteoclasts is responsible for degrading organic bone matrix. People with pathologic bone resorption have higher circulating CatK concentrations., Hypothesis: Canine osteosarcoma (OS) cells will possess CatK, and its secretion will be cytokine inducible. Circulating CatK concentrations will be increased in dogs with OS, and will be a surrogate marker of bone resorption., Animals: Fifty-one dogs with appendicular OS and 18 age- and weight-matched healthy control dogs., Methods: In a prospective study, expressions of CatK mRNA and protein were investigated in OS cells. The inducible secretion and proteolytic activity of CatK from OS cells was assessed in vitro. Serum CatK concentrations were quantified in normal dogs and dogs with OS and its utility as a bone resorption marker was evaluated in dogs with OS treated with palliative radiation and antiresorptive agents., Results: Canine OS cells contain preformed CatK within cytoplasmic vesicles. In OS cells, TGFβ1 induced the secretion of CatK, which degraded bone-derived type I collagen in vitro. CatK concentrations were higher in dogs with OS than healthy dogs (11.3 ± 5.2 pmol/L versus 8.1 ± 5.0 pmol/L, P = .03). In a subset of dogs with OS, pretreatment CatK concentrations gradually decreased after palliative radiation and antiresorptive treatment, from 9.3 ± 3.2 pmol/L to 5.0 ± 3.1 pmol/L, P = .03., Conclusions and Clinical Importance: Canine OS is associated with pathologic bone resorption, and CatK inhibitors might aid in the management of canine OS-related malignant osteolysis., (Copyright © 2011 by the American College of Veterinary Internal Medicine.)

Neutropenia is a serious hematopathologic change that should not be ignored. In almost all patients, it is an important primary or secondary indicator of significant underlying disease. While in some neutropenic patients the diagnostic work up will be simple, in others it is challenging. The value of examining a blood smear for toxic changes in neutrophils cannot be overemphasized; it may indicate the presence of systemic inflammation, as well as providing clues about prognosis and the extent of treatment the patient may require.

There is little information in veterinary literature regarding the diagnostic accuracy of aspirate cytology for the diagnosis of canine osteosarcoma (OSA). The authors compared the diagnostic accuracy of a novel method of cytologic collection, termed core aspirate cytology (CA), with fine needle aspiration (FNA) and histopathology in 27 dogs with lytic and/or proliferative bone lesions. Alkaline phosphatase (ALP) staining was performed to confirm the diagnosis of OSA cytologically. OSA was accurately diagnosed in 85% and 95% of FNA and CA, respectively. ALP staining was 100% sensitive for the diagnosis of OSA. CA using a bone marrow biopsy needle allowed for penetration of cortical bone and aspirate cytology with a larger bore needle than FNA; however, there was no significant difference in diagnostic accuracy between techniques. Aspirate cytology with ALP staining was a safe, accurate, and minimally invasive diagnostic test for the evaluation of suspected OSA lesions in dogs.

Objective: To evaluate a commercially available modified-live Streptococcus equi subsp equi vaccine for safety and persistence in vaccinated ponies and to detect recombination or reversion events in the vaccine strain., Animals: 5 ponies that were 1.5 to 8 years old (group 1) and 4 ponies that were 6 months old (group 2)., Procedures: Ponies were vaccinated, with a subsequent booster vaccination 2 to 3 weeks later, and monitored for 50 days. At booster vaccination, an equal amount of a tetracycline-resistant wild-type strain of S equiwas administered. Recovery of all strains was performed by use of bacteriologic culture and PCR assays., Results: Ponies in group 1 had background antibody titers against S equi antigen before vaccination despite the lack of known exposure to S equi. Ponies in group 2 were immunologically naïve. Increases in anti-S equi antibody titers were detected in both groups. Ponies in group 1 did not have clinical signs of disease caused by S equi. In group 2, all ponies developed abscesses in retropharyngeal lymph nodes; 1 pony developed severe clinical disease and was euthanized. The vaccine strain was recovered from ponies in group 2 for up to 24 days after vaccination., Conclusions and Clinical Significance: Although the vaccine was successful in inducing IgG antibodies against S equi in all ponies, findings suggested that the vaccine may have caused substantial morbidity and some deaths in the young ponies. In young ponies, the vaccine strain persisted in tissues for weeks; however, no evidence of recombination was detected.

Stably incorporating fluorescent molecules to polymeric nanoparticles (NPs) or micelles can facilitate the prolonged tracking of these drug-delivery vehicles in vitro and in vivo. However, incorporation of fluorescent molecules, usually charged and thereby water-soluble, through the encapsulation strategy to hydrophobic polymer matrices is challenging. The encapsulated fluorescent agents are also subject to rapid release when the polymeric NPs are exposed to biological media. To address this issue, we developed Cy5-conjugated polylactide (Cy5-PLA) NPs through Cy5/(BDI)ZnN(TMS)2 [(BDI) = 2-((2,6-diisopropylphenyl)amido)-4-((2,6-diisopropylphenyl)-imino)-2-pentene]-mediated ring-opening polymerization of lactide (LA) followed by nanoprecipitation. This process allows for covalent conjugation of Cy5 to PLA with quantitative incorporation efficiency and formulation of Cy5-PLA NPs with controlled particles size (approximately 100 nm). As much as 80% of Cy5 was still present in the Cy5-PLA NPs after theses NPs were incubated in PBS at 37 degrees C for 12 days. Cy5-PLA NPs were conjugated to the A10 RNA aptamer that binds to the prostate-specific membrane antigen (PSMA). The resulting Cy5-PLA/aptamer NPs were found to only bind to and get internalized by LNCaP and canine prostate adenocarcinoma cells (PSMA-positive), but not to PC3 cells (PSMA-negative). The Cy5-PLA NPs were administered to balb/c mice intravenously and found to have excellent signals with low-background fluorescence in various organs.

Objective: To determine concentrations of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) in equine chondrocytes and synoviocytes and to quantify changes in the OPG:RANKL ratio in response to exogenous factors., Sample Population: Samples of articular cartilage and synovium with grossly normal appearance obtained from metacarpophalangeal and metatarsophalangeal joints of 5 adult (1- to 8-year-old) horses., Procedures: Cell cultures of chondrocytes and synoviocytes were incubated with human recombinant interleukin-1beta (hrIL-1beta; 10 ng/mL), lipopolysaccharide (LPS; 10 microg/mL), or dexamethasone (100nM) for 48 hours. Negative control cultures received no treatment. Cells and spent media were assayed for RANKL and OPG concentrations by use of western blot and immunocytochemical analyses. Spent media were also assayed for OPG concentration by use of an ELISA., Results: RANKL and OPG were expressed in equine chondrocytes and synoviocytes in vitro. Cell-associated RANKL and OPG concentrations were not impacted by exogenous factors. Soluble RANKL release into media was significantly increased by hrIL-1beta in chondrocyte but not in synoviocyte cultures. Soluble OPG release into media was significantly increased by hrIL-1beta and LPS in chondrocyte but not in synoviocyte cultures. The soluble OPG:RANKL ratio was significantly increased by LPS in chondrocyte cultures. Dexamethasone decreased OPG expression in synoviocytes., Conclusions and Clinical Relevance: RANKL and OPG proteins were expressed in equine articular cells. Release of these proteins may affect osteoclastogenesis within adjacent subchondral bone. Thus, RANKL and OPG may have use as biomarkers and treatment targets in horses with joint disease.

An 8-year-old male castrated Domestic Short-haired cat was examined for a 1-week history of blepharospasm and mucoid ocular discharge OS. Examination revealed ulcerative keratitis with stromal loss, stromal infiltrate, corneal edema, perilimbal vascularization and miosis. Cytology of the cornea revealed multiple dichotomously branching, septate fungal hyphae and severe, predominantly neutrophilic inflammation. PCR of the cytology samples confirmed the presence of Aspergillus flavus while fungal and bacterial cultures were negative. Treatment with topical 1% voriconazole solution was successful in resolving the keratomycosis.

Background: The tropomyosin-related kinase A (TrkA) proto-oncogene encodes for a receptor that binds with high affinity to the neurotrophin ligand, nerve growth factor (NGF). Intracellular signaling mediated by the TrkA/NGF axis orchestrates neuronal cell differentiation, mitogenesis, and survival. Interestingly, TrkA also is expressed by bone forming cells, and its signaling promotes antiapoptotic effects in actively dividing osteoblasts., Hypothesis: In canine immortalized cell lines and naturally occurring tumor samples, osteosarcoma (OSA) cells will express TrkA. In canine OSA cell lines, TrkA signaling will promote cell mitogenesis and survival., Methods: In vitro, TrkA expression in canine OSA cell lines was assessed by reverse transcriptase-polymerase chain reaction, flow cytometry, and immunocytochemistry. In vitro, the involvement of TrkA-mediated signaling for cell mitogenesis and survival were investigated with commercially available assays. In vivo, TrkA expression was evaluated in primary tumors and pulmonary metastases with immunocytochemistry and immunohistochemistry, respectively., Results: In vitro, canine OSA cells expressed TrkA mRNA and protein. Ligation of TrkA with exogenous NGF did not induce mitogenesis. Blockade of TrkA signaling with either a protein kinase inhibitor or NGF-neutralizing antibody induced apoptosis of canine OSA cell lines. In vivo, the majority (10/15) of canine OSA primary tumors and pulmonary metastases (9/12) expressed TrkA protein., Conclusions and Clinical Importance: Canine OSA cells express TrkA, and its signaling protects against apoptosis. Most dogs with spontaneously arising OSA express TrkA within their primary tumors and pulmonary metastatic lesions, warranting further investigations with TrkA antagonists as a novel treatment option for canine OSA.

Background: Chemokine receptors (CXCRs) are transmembrane proteins classically studied for their participation in leukocyte homing. By their binding of cognate ligands, CXCRs orchestrate key cellular processes, including directional migration. Several different CXCRs are expressed on cancer cells and dictate tissue-specific metastases. In pediatric osteosarcoma (OSA), CXCR4 expression by tumor cells may participate in metastasis to tissues containing CXCL12, the partnering ligand for CXCR4. Canine and pediatric OSA share many biological similarities, including preferential metastasis to lung, bone, and lymph node., Hypothesis: In canine immortalized cell lines and naturally occurring tumor samples, OSA cells will express CXCR4. In canine OSA cell lines, CXCR4 will participate in directional cell migration., Methods: In vitro, CXCR4 expression in canine OSA cell lines was assessed by reverse-transcriptase polymerase chain reaction, Western blot analysis, flow cytometry, and immunocytochemistry. In vitro, involvement of CXCR4-mediated signaling for directional migration was investigated with a commercial assay. In vivo, CXCR4 expressions were evaluated in primary tumors and pulmonary metastases with immunocytochemistry and immunohistochemistry, respectively., Results: In vitro, canine OSA cells express CXCR4 mRNA and protein. Ligation of CXCR4 with exogenous CXCL12 results in directional migration of canine OSA cell lines. In vivo, majority (8/11) of the canine OSA primary tumors, but minority (2/8) of the pulmonary metastases express CXCR4 protein., Conclusions and Clinical Importance: Canine OSA cells express CXCR4, and its signaling participates in directional migration. Most dogs with spontaneously arising OSA express CXCR4 within their primary tumors.

Background: Feline oral squamous cell carcinoma (OSCC) may cause painful bone destruction. Given the local invasiveness and rapid clinical progression of OSCC, conventional therapies are often palliative. In human cancer patients, zoledronate exerts anticancer effects by inhibiting tumor-induced angiogenesis and malignant osteolysis., Hypothesis: Zoledronate will exert in vitro and in vivo anti-angiogenic and antiresorptive effects in feline OSCC., Animals: Eight cats with OSCC were prospectively treated with zoledronate and conventional treatment modalities., Methods: In vitro, zoledronate's effects in modulating soluble vascular endothelial growth factor (VEGF) secretion and receptor activator of nuclear factor kappaB (NF-kappaB) ligand (RANKL) expression were investigated in a feline OSCC cell line (SCCF1). In vivo, basal serum C-telopeptide (CTx) concentrations were compared among normal and OSCC-bearing cats, and the biologic effects of zoledronate administration in cats with naturally occurring OSCC were quantified by serially assessing circulating serum VEGF and CTx concentrations., Results: In vitro, zoledronate concentrations greater than 3 microM reduce soluble VEGF secretion in the SCCF1 cell line. The expression of RANKL in the SCCF1 cell line was also modulated by zoledronate, with low concentrations (3 microM) decreasing but higher concentrations (30 microM) increasing RANKL expression in comparison with untreated cells. In vivo, cats with bone-invasive OSCC had greater serum CTx concentrations in comparison with geriatric, healthy controls. Treatment with zoledronate rapidly decreased circulating serum VEGF and CTx concentrations in cats with spontaneously occurring OSCC., Conclusions and Clinical Importance: Zoledronate exerts in vitro and in vivo effects that may favor the slowing of tumor growth and pathologic bone turnover associated with OSCC.

Background: Cyclooxygenase-2 (COX-2) and its principle enzymatic metabolite, prostaglandin E2 (PGE2), are implicated in cancer progression. Based upon immunohistochemical (IHC) evidence that several tumor types in animals overexpress COX-2 protein, COX-2 inhibitors are used as anticancer agents in dogs and cats., Hypothesis: IHC is inaccurate for assessing tumor-associated COX-2 protein and enzymatic activity., Methods: Five mammalian cell lines were assessed for COX-2 protein expression by IHC and Western blot analysis (WB), and functional COX-2 activity was based upon PGE2 production., Results: Detection of COX-2 protein by IHC and WB were in agreement in 4 of 5 cell lines. In 1 cell line that lacked COX-2 gene transcription because of promoter hypermethylation (HCT-116), IHC produced false-positive staining for COX-2 protein expression. Functional COX-2 enzymatic activity was dissociated from relative IHC-based COX-2 protein expression in 2 cell lines (RPMI 2650 and SCCF1). The RPMI 2650 cell line demonstrated strong COX-2 protein expression but minimal PGE2 production., Conclusions and Clinical Importance: Western blot is more accurate than IHC for the detection of COX-2 protein in the cell lines studied. Furthermore, the semiquantitative identification of COX-2 protein by IHC or WB does not necessarily correlate with enzymatic activity. Based upon the potential inaccuracy of IHC and dissociation of COX-2 protein expression from enzymatic activity, the practice of instituting treatment of tumors with COX-2 inhibitors based solely on IHC results should be reconsidered.

Bone marrow aspiration for routine staging of canine cutaneous mast cell tumour is not consistently performed, and the overall incidence of bone marrow infiltration and predictive value of the complete blood count (CBC) is unknown. This study evaluated a series of 157 dogs presented for cutaneous mast cell tumours in which a CBC and bone marrow aspiration were performed. The incidence of bone marrow infiltration at initial staging was low at 2.8%, and 4.5% overall. Factors significantly associated with bone marrow infiltration included increased age, leucocytosis, anaemia, neutrophilia, monocytosis, eosinophilia, thrombocytopenia, being purebred and staging at the time of recurrent or progressive disease. Our study suggests that a bone marrow sample is not indicated for routine staging but maybe indicated for those dogs with mast cell tumours having either an abnormal haemogram (neutrophilia, monocytosis, eosinophilia, basophilia, anaemia and thrombocytopenia) or presenting for tumour regrowth, progression or new occurrence.

Background: Receptor activator of nuclear factor kappa-B (RANK), RANK-ligand (RANKL), and the soluble decoy receptor osteoprotegerin (OPG) form a key axis modulating osteoclastogenesis. In health, RANKL-expressing bone stromal cells and osteoblasts activate osteoclasts through RANK ligation, resulting in homeostatic bone resorption. Skeletal tumors of dogs and cats, whether primary or metastatic, may express RANKL and directly induce malignant osteolysis., Hypothesis: Bone malignancies of dogs and cats may express RANKL, thereby contributing to pathologic bone resorption and pain. Furthermore, relative RANKL expression in bone tumors may correlate with radiographic characteristics of bone pathology., Animals: Forty-two dogs and 6 cats with spontaneously-occurring tumors involving bones or soft tissues were evaluated., Methods: A polyclonal anti-human RANKL antibody was validated for use in canine and feline cells by flow cytometry and immunocytochemistry. Fifty cytologic specimens were collected from bone and soft tissue tumors of 48 tumor-bearing animals and assessed for RANKL expression. In 15 canine osteosarcoma (OSA) samples, relative RANKL expression was correlated with radiographic characteristics of bone pathology., Results: Expression of RANKL by neoplastic cells was identified in 32/44 canine and 5/6 feline tumor samples. In 15 dogs with OSA, relative RANKL expression did not correlate with either radiographic osteolysis or bone mineral density as assessed by dual energy x-ray absorptiometry., Conclusions and Clinical Importance: In dogs and cats, tumors classically involving bone and causing pain, often may express RANKL. Confirming RANKL expression in tumors is a necessary step toward the rational institution of novel therapies targeting malignant osteolysis via RANKL antagonism.

A 6-year-old, neutered male Rottweiler was presented to the University of Illinois Veterinary Teaching Hospital because of a lytic bone lesion involving the distal portion of the right radius and possible pulmonary metastases on thoracic radiographs. Results of serum biochemical analysis were unremarkable. Aspiration and cytologic examination of the bone lesion indicated likely sarcoma with reactive bone. Cutaneous masses were found on the left thigh, interscapular region, and dorsal lumbar region, 4 weeks after initial presentation. Neoplastic spindle cells were found in aspirates from 2 of the masses. The neoplastic cells stained positive for alkaline phosphatase activity using cytochemistry. Re-evaluation of serum biochemical values at this time revealed a marked increase in alkaline phosphatase activity (413 U/L, reference interval 12-110 U/L) compared with the initial value (26 U/L). Due to progressive disease, the dog was euthanized and a necropsy was performed. Histologic findings included primary osteosarcoma of the distal portion of the right radius, with metastases in the lungs, spleen, left fourth and fifth ribs, soft tissue of the right medial thigh, and T1-T3/interscapular region. Cutaneous metastasis of primary appendicular osteosarcoma has been reported rarely in animals and humans. Increased serum alkaline phosphatase activity may be a potential indicator of poor prognosis for this neoplasm.

Objective: To determine the effect of continuous IV administration of 50% dextrose solution on phosphorus homeostasis in lactating dairy cows., Design: Clinical trial., Animals: 4 multiparous Jersey cows., Procedures: Cows were administered 50% dextrose solution IV (0.3 g/kg/h [0.14 g/lb/h]) for 5 days. Plasma concentrations of glucose, immune-reactive insulin (IRI), and phosphorus were determined before, during, and for 72 hours after dextrose infusion. Phosphorus intake and losses of phosphorus in urine, feces, and milk were determined. Each cow received a sham treatment that included instrumentation and sampling but not administration of dextrose., Results: Plasma glucose, IRI, and phosphorus concentrations were stable during sham treatment. Plasma phosphorus concentration decreased rapidly after onset of dextrose infusion, reaching a nadir in 24 hours and remaining less than baseline value for 36 hours. Plasma phosphorus concentration increased after dextrose infusion was stopped, peaking in 6 hours. Urinary phosphorus excretion did not change during dextrose infusion, but phosphorus intake decreased because of reduced feed intake, followed by decreased fecal phosphorus loss and milk yield. Rapid changes in plasma phosphorus concentration at the start and end of dextrose infusion were temporally associated with changes in plasma glucose and IRI concentrations and most likely caused by compartmental shifts of phosphorus., Conclusions and Clinical Relevance: Hypophosphatemia developed in response to hyperglycemia or hyperinsulinemia in dairy cows administered dextrose via continuous IV infusion. Veterinarians should monitor plasma phosphorus concentration when administering dextrose in this manner, particularly in cows with decreased appetite or preexisting hypophosphatemia.

Objective: To evaluate clinical and laboratory findings, treatment, and clinical outcome in cats with blastomycosis., Design: Retrospective case series., Animals: 8 cats with naturally occurring blastomycosis., Procedures: Medical records of the University of Illinois Veterinary Teaching Hospital were searched for cases of blastomycosis in cats diagnosed via cytologic or histopathologic findings. Clinical and laboratory findings, treatment, and clinical outcome were determined. Radiographs were reviewed for the 8 cases., Results: All cats were systemically ill. Respiratory tract signs and dermal lesions were most commonly observed. All cats had radiographic evidence of respiratory tract disease. Seven of the 8 cats had ill-defined soft-tissue opacities (nodules or masses) or alveolar consolidation of the lungs. Antemortem diagnosis was achieved cytologically in 6 of the 8 cats, and 3 were successfully treated and survived., Conclusions and Clinical Relevance: In contrast to previous reports, diagnosis was achieved antemortem in most of the cats (all by cytologic identification of the organism). Clinical signs, laboratory findings, and outcome were similar to previous descriptions of this rare disease in cats.

A 3-year-old Boxer was presented with progressive diarrhea, vomiting, and lethargy of 5-months duration. The dog had watery black feces, a mature neutrophilia, and microcytic anemia. Cytologic evaluation of a direct fecal smear stained with Wright's-Giemsa revealed numerous encapsulated, narrow-based, budding organisms consistent with Cryptococcus sp. Pyogranulomatous inflammation and Cryptococcus organisms also were observed in ultrasound-guided fine-needle aspirates of the small intestine and mesenteric lymph nodes, and in histologic sections of colonic biopsies obtained by endoscopy. Multifocal chorioretinitis by fundic examination was consistent with systemic mycosis, and the reciprocal antigen titer (1600) on a cryptococcal antigen latex agglutination test for Cryptococcus neoformans was markedly increased. Using immunohistochemistry, the organism was identified further as C neoformans var. grubii (C neoformans var. neoformans serotype A). After 3 weeks of antifungal treatment, ultrasound examination revealed urinary bladder wall thickening, and Cryptococcus organisms were found in a urine sediment preparation. After 4 months of treatment, the dog was clinically normal and had no abnormal findings on CBC, serum biochemistry, urinalysis, or fecal cytology; however, the antigen titer remained unchanged, mesenteric lymphadenomegaly and jejunal wall thickening were still evident, and cytologic evaluation of fine-needles aspirates of the jejunal wall revealed budding Cryptococcus organisms. Intestinal involvement in dogs with cryptococcosis is rare, and diagnosis by fecal cytology has not been documented previously.

Objectives: To examine the incidence of elevated corticosteroid-induced alkaline phosphatase (sALP) in dogs with lymphoma and to determine if sALP is a reliable prognostic indicator in canine lymphoma., Methods: The medical records of 62 canine lymphoma patients treated with a combination chemotherapy protocol from 1994 to 2003 at the University of Illinois Veterinary Teaching Hospital were examined. Variables assessed with respect to response rate and remission duration included age, bodyweight, sex, breed, World Health Organization stage (I to V), substage (a or b), pretreatment administration of corticosteroid, and serum levels of alkaline phosphatase, sALP and alanine aminotransferase., Results: sALP was not statistically significant with respect to response rate or duration of remission, nor was preinduction glucocorticoid administration. Stage was significant with respect to achieving remission., Clinical Significance: It was found that sALP is not a useful prognostic indicator for response rate and remission duration in dogs with lymphoma.

In conclusion, the CBC can be a powerful diagnostic tool. Appropriate evaluation of all aspects of the CBC can lead to a specific diagnosis or assist in ruling out many diseases. To gain the full benefit of the CBC, it must be used in conjunction with a good history and physical examination as well as with additional components of the minimum database, which include a chemistry panel and urinalysis.