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Myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are heterogeneous neoplasms of hematopoietic stem cells that are challenging to diagnose, differentiate, and prognosticate. Cytogenetic and mutational analyses are useful in humans but unavailable for dogs, where diagnosis and classification still rely largely on hematologic and morphologic assessment. The objectives of this study were to apply a classification scheme to myeloid neoplasms and to assess outcome in relation to predictor variables. Keyword search of a laboratory database, application of sequential exclusion criteria, and consensus from 3 reviewers yielded 70 cases of myeloid neoplasia with hematology results, and cytologic (11), histologic (14), or both (45) types of marrow specimens. Based on blast percentage and morphology, 42 cases were classified as MDS and 28 as AML. Dogs with MDS had significantly lower body weights, hemoglobin concentrations and blood blasts, and higher red blood cell size variability and platelet numbers than dogs with AML. Estimates of median survival using Kaplan-Meier curves for dogs with MDS and AML were 384 and 6 days, respectively ( P < .001). The instantaneous risk of death for dogs with MDS was approximately 5× lower than that of dogs with AML. Significant predictor variables of survival were body weight, white blood cell count, platelet count, and percent blood blasts ( P < .05). Hazard ratios (HRs) derived from best-fitting Cox regression models were 1.043, 0.998, and 1.061 for increased neutrophils, decreased platelets, and increased blood blasts, respectively. Findings from this study suggest that hematologic and morphologic variables are useful to predict outcomes in myeloid neoplasia., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: The primary objective of this cross-sectional study, conducted in Québec and Bristish Columbia (Canada) between February 2021 and January 2022, was to measure the prevalence of viral RNA in oronasal and rectal swabs and serum antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) amongst cats living in households with at least one confirmed human case. Secondary objectives included a description of potential risk factors for the presence of SARS-CoV-2 antibodies and an estimation of the association between the presence of viral RNA in swabs as well as SARS-CoV-2 antibodies and clinical signs. Oronasal and rectal swabs and sera were collected from 55 cats from 40 households at most 15 days after a human case confirmation, and at up to two follow-up visits. A RT-qPCR assay and an ELISA were used to detect SARS-CoV-2 RNA in swabs and serum SARS-CoV-2 IgG antibodies, respectively. Prevalence and 95% Bayesian credibility intervals (BCI) were calculated, and associations were evaluated using prevalence ratio and 95% BCI obtained from Bayesian mixed log-binomial models., Results: Nine (0.16; 95% BCI = 0.08-0.28) and 38 (0.69; 95% BCI = 0.56-0.80) cats had at least one positive RT-qPCR and at least one positive serological test result, respectively. No risk factor was associated with the prevalence of SARS-CoV-2 serum antibodies. The prevalence of clinical signs suggestive of COVID-19 in cats, mainly sneezing, was 2.12 (95% BCI = 1.03-3.98) times higher amongst cats with detectable viral RNA compared to those without., Conclusions: We showed that cats develop antibodies to SARS-CoV-2 when exposed to recent human cases, but detection of viral RNA on swabs is rare, even when sampling occurs soon after confirmation of a human case. Moreover, cats with detectable levels of virus showed clinical signs more often than cats without signs, which can be useful for the management of such cases., (© 2024. The Author(s).)

Fixation and demineralization protocols for bone marrow (BM) across diagnostic laboratories are not standardized. How different protocols affect histomorphology and DNA amplification is incompletely understood. In this study, 2 fixatives and 3 demineralization methods were tested on canine BM samples. Twenty replicate sternal samples obtained within 24 hours of death were fixed overnight in either acetic acid-zinc-formalin (AZF) or 10% neutral-buffered formalin (NBF) and demineralized with formic acid for 12 hours. Another 53 samples were fixed in AZF and demineralized with hydrochloric acid for 1-hour, formic acid for 12 hours, or ethylenediamine tetraacetic acid (EDTA) for 24 hours. Histologic sections were scored by 4 raters as of insufficient, marginal, good, or excellent quality. In addition, DNA samples extracted from sections treated with the different fixation and demineralization methods were amplified with 3 sets of primers to conserved regions of T cell receptor gamma and immunoglobulin heavy chain genes. Amplification efficiency was graded based on review of capillary electrophoretograms. There was no significant difference in the histomorphology scores of sections fixed in AZF or NBF. However, EDTA-based demineralization yielded higher histomorphology scores than demineralization with hydrochloric or formic acid, whereas formic acid resulted in higher scores than hydrochloric acid. Demineralization with EDTA yielded DNA amplification in 29 of 36 (81%) samples, whereas demineralization with either acid yielded amplification in only 2 of 72 (3%) samples. Although slightly more time-consuming and labor-intensive, tissue demineralization with EDTA results in superior morphology and is critical for polymerase chain reaction (PCR) amplification with the DNA extraction method described in this article., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Two cat nasal swabs from Canada's earliest confirmed SARS-CoV-2 positive domestic cats were sequenced to over 99% SARS-CoV-2 genome coverage. One cat had lineage A.23.1 SARS-CoV-2 not reported before in animals. Both sequences have multiple spike gene mutations and clustered closely with human-derived sequences in the global SARS-CoV-2 phylogenetic tree., Competing Interests: The authors declare no conflict of interest.

Objectives: The aim of the present study was to establish a reference interval (RI) for urine kidney injury molecule-1 (KIM-1) in healthy cats., Methods: History, physical examination, blood pressure, and feline immunodeficiency virus and feline leukemia virus serology status were determined. A complete blood cell count, serum biochemical profile, urinalysis and kidney ultrasound were performed, and N-terminal pro-brain natriuretic peptide, total thyroxine (TT4) and urine KIM-1 were measured. An RI was calculated and the effect of age, sex, body condition score (BCS), blood pressure, symmetric dimethylarginine (SDMA), serum creatinine concentration (SCr), phosphorus, TT4, urine specific gravity (USG) and mid-sagittal kidney length on urine KIM-1 was evaluated using a general linear model., Results: Of 69 recruited cats, 50 met the inclusion criteria. There were 35 male cats and 15 female cats, with a median age of 4.3 years (range 1.0-12.3), median weight of 5.11 kg (range 2.52-8.45) and median BCS of 6/9 (range 3-8). The median serum concentrations were SDMA 11.0 µg/dl (range 2-14), SCr 88.5 µmol/l (range 47-136), phosphorus 1.41 mmol/l (range 0.8-2.2) and TT4 32.0 nmol/l (range 17-51). Median USG was 1.057 (range 1.035-1.076), mid-sagittal left kidney length was 3.50 cm (range 2.94-4.45) and mid-sagittal right kidney length was 3.70 cm (range 3.06-4.55). The derived RI for urine KIM-1 was 0.02-0.68. USG was a significant ( P <0.001) predictor of urine KIM-1. Individually, age, sex, blood pressure, BCS, SDMA, SCr, phosphorus, TT4 and mid-sagittal kidney length were not significant predictors of urine KIM-1. In a multivariate model, if combined with USG, SDMA concentration was predictive ( P  = 0.030) of urine KIM-1., Conclusions and Relevance: Urine concentration was significantly correlated with urine KIM-1, which will be an important consideration when interpreting findings in cats with potential kidney injury., Competing Interests: Conflict of interestThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We collected oral and/or rectal swabs and serum from dogs and cats living in homes with SARS-CoV-2-PCR-positive persons for SARS-CoV-2 PCR and serology testing. Pre-COVID-19 serum samples from dogs and cats were used as negative controls, and samples were tested in duplicate at different timepoints. Raw ELISA results scrutinized relative to known negative samples suggested that cut-offs for IgG seropositivity may require adjustment relative to previously proposed values, while proposed cut-offs for IgM require more extensive validation. A small number of pet dogs (2/43, 4.7%) and one cat (1/21, 4.8%) were positive for SARS-CoV-2 RNA, and 28.6 and 37.5% of cats and dogs were positive for anti-SARS-CoV-2 IgG, respectively., Competing Interests: Dorothee Bienzle is an Academic Editor for PeerJ., (©2023 Gin et al.)

Case Series Summary: A total of 1692 medical records from a primary care feline practice and a veterinary referral hospital were evaluated retrospectively to assess discordant feline leukemia virus (FeLV) test results. In total, 73 cats were positive for FeLV using serum in a lateral flow immunoassay (LFI) or laboratory-based ELISA. Of these cats, 21 subsequently tested negative for FeLV proviral DNA by non-quantitative PCR on EDTA whole blood (16/21, 76.2%), bone marrow (4/21, 19%) or both (1/21, 4.7%). The proportional morbidity (an estimate of prevalence in a sample of the total population) for FeLV by LFI/ELISA and PCR assays was 3.1%, consistent with that reported in previous studies for cats in North America. Cats with discordant LFI/ELISA and PCR results had either primary bone marrow disease (18 autoimmune, one neoplastic), a bone marrow insult (hemotrophic mycoplasmosis) or systemic inflammation (pyothorax with a marked neutrophilic leukocytosis). The percentage of cats with a positive LFA/ELISA result and negative PCR assay surviving to discharge was 85.7% (18/21). Of these, 88.9% (16/18) survived 4 months to 6 years. Seven cats (33.3%) were re-tested with LFI or ELISA once primary disease was controlled, and all tested negative., Relevance and Novel Information: These findings indicate that in cats with bone marrow disease that shares features of progressive FeLV infection, positive LFI and ELISA FeLV test results should be followed up with FeLV proviral DNA PCR testing, particularly in populations where disease prevalence is low.

Alveolar macrophages (AMs) are the predominant innate immune cell in the distal respiratory tract. During inflammatory responses, AMs may be supplemented by blood monocytes, which differentiate into monocyte-derived macrophages (MDMs). Macrophages play important roles in a variety of common equine lower airway diseases, including severe equine asthma (SEA). In an experimental model, an inhaled mixture of Aspergillus fumigatus spores, lipopolysaccharide, and silica microspheres (FLS), induced SEA exacerbation in susceptible horses. However, whether equine AMs and MDMs have differing immunophenotypes and cytokine responses to FLS stimulation is unknown. To address these questions, alveolar macrophages/monocytes (AMMs) were isolated from bronchoalveolar lavage fluid and MDMs derived from blood of six healthy horses. Separately, AMMs and MDMs were cultured with and without FLS for six hours after which cell surface marker expression and cytokine production were analyzed by flow cytometry and a bead-based multiplex assay, respectively. Results showed that regardless of exposure conditions, AMMs had significantly higher surface expression of CD163 and CD206 than MDMs. Incubation with FLS induced secretion of IL-1β, IL-8, TNF-α and IFN-γ in AMMs, and IL-8, IL-10 and TNF-α in MDMs. These results suggest that AMMs have a greater proinflammatory response to in vitro FLS stimulation than MDMs, inferring differing roles in equine lung inflammation. Variability in recruitment and function of monocyte-macrophage populations warrant more detailed in vivo investigation in both homeostatic and diseased states., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Kang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

An 8-wk-old, male, mixed-breed puppy was adopted from a rescue organization. From the time of adoption, the puppy suffered episodes of illness affecting various organ systems, which resolved with supportive therapy but relapsed once medical therapy was discontinued. Review of the hematologic data revealed cyclic fluctuations in circulating blood cells. Cyclicity was most prominent in neutrophils, with recurrent severe neutropenia. Neutropenic episodes lasted 5-6 d, with regular cycles of 11-14 d between nadir neutrophil counts. Genetic testing determined that the patient was homozygous mutant for the frameshift mutation in the adaptor protein complex 3 β-subunit ( AP3B1 ) gene, originally identified in gray collies with cyclic hematopoiesis (CH). Pedigree information was not available, but the patient's features were phenotypically distinct from those of collies. We describe here a case of the AP3B1 mutation in a mixed-breed dog that did not resemble a collie, undescribed previously, to our knowledge. Our findings indicate that the AP3B1 mutation and CH are present within the general canine population and are not restricted to collies.

Pulmonary hemorrhage (P-Hem) occurs among multiple species and can have various causes. Cytology of bronchoalveolar lavage fluid (BALF) using a 5-tier scoring system of alveolar macrophages based on their hemosiderin content is considered the most sensitive diagnostic method. We introduce a novel, fully annotated multi-species P-Hem dataset, which consists of 74 cytology whole slide images (WSIs) with equine, feline and human samples. To create this high-quality and high-quantity dataset, we developed an annotation pipeline combining human expertise with deep learning and data visualisation techniques. We applied a deep learning-based object detection approach trained on 17 expertly annotated equine WSIs, to the remaining 39 equine, 12 human and 7 feline WSIs. The resulting annotations were semi-automatically screened for errors on multiple types of specialised annotation maps and finally reviewed by a trained pathologist. Our dataset contains a total of 297,383 hemosiderophages classified into five grades. It is one of the largest publicly available WSIs datasets with respect to the number of annotations, the scanned area and the number of species covered., (© 2022. The Author(s).)

We tested swab specimens from pets in households in Ontario, Canada, with human COVID-19 cases by quantitative PCR for SARS-CoV-2 and surveyed pet owners for risk factors associated with infection and seropositivity. We tested serum samples for spike protein IgG and IgM in household pets and also in animals from shelters and low-cost neuter clinics. Among household pets, 2% (1/49) of swab specimens from dogs and 7.7% (5/65) from cats were PCR positive, but 41% of dog serum samples and 52% of cat serum samples were positive for SARS-CoV-2 IgG or IgM. The likelihood of SARS-CoV-2 seropositivity in pet samples was higher for cats but not dogs that slept on owners' beds and for dogs and cats that contracted a new illness. Seropositivity in neuter-clinic samples was 16% (35/221); in shelter samples, 9.3% (7/75). Our findings indicate a high likelihood for pets in households of humans with COVID-19 to seroconvert and become ill.

Although myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) has a specific and distinctive profile of clinical features, the disease remains an enigma because causal explanation of the pathobiological matrix is lacking. Several potential disease mechanisms have been identified, including immune abnormalities, inflammatory activation, mitochondrial alterations, endothelial and muscular disturbances, cardiovascular anomalies, and dysfunction of the peripheral and central nervous systems. Yet, it remains unclear whether and how these pathways may be related and orchestrated. Here we explore the hypothesis that a common denominator of the pathobiological processes in ME/CFS may be central nervous system dysfunction due to impaired or pathologically reactive neuroglia (astrocytes, microglia and oligodendrocytes). We will test this hypothesis by reviewing, in reference to the current literature, the two most salient and widely accepted features of ME/CFS, and by investigating how these might be linked to dysfunctional neuroglia. From this review we conclude that the multifaceted pathobiology of ME/CFS may be attributable in a unifying manner to neuroglial dysfunction. Because the two key features - post exertional malaise and decreased cerebral blood flow - are also recognized in a subset of patients with post-acute sequelae COVID, we suggest that our findings may also be pertinent to this entity., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Renz-Polster, Tremblay, Bienzle and Fischer.)

Background: Lymphocytic neoplasms with frequent reactive lymphocytes are uncommonly reported in dogs, and can pose a diagnostic challenge. Different diagnostic modalities such as cytology, flow cytometry, histopathology, immunohistochemistry, and clonality testing, are sometimes required for a diagnosis. This report illustrates the value of using a multi-modal diagnostic approach to decipher a complex lymphocytic tumor, and introduces immune repertoire sequencing as a diagnostic adjunct., Case Presentation: A 10-month-old Great Dane was referred for marked ascites. Cytologic analysis of abdominal fluid and hepatic aspirates revealed a mixed lymphocyte population including numerous large lymphocytes, yielding a diagnosis of lymphoma. Flow cytometrically, abdominal fluid lymphocytes were highly positive for CD4, CD5, CD18, CD45, and MHC II, consistent with T cell lymphoma. Due to a rapidly deteriorating clinical condition, the dog was euthanized. Post mortem histologic evaluation showed effacement of the liver by aggregates of B cells surrounded by T cells, suggestive of hepatic T cell-rich large B cell lymphoma. Immune repertoire sequencing confirmed the presence of clonal B cells in the liver but not the abdominal fluid, whereas reactive T cells with shared, polyclonal immune repertoires were found in both locations., Conclusions: T cell-rich large B cell lymphoma is a rare neoplasm in dogs that may be challenging to diagnose and classify due to mixed lymphocyte populations. In this case, the results of histopathology, immunohistochemistry and immune repertoire sequencing were most consistent with a hepatic B cell neoplasm and reactive T cells exfoliating into the abdominal fluid. Immune repertoire sequencing was helpful in delineating neoplastic from reactive lymphocytes and characterizing repertoire overlap in both compartments. The potential pitfalls of equating atypical cytomorphology and monotypic marker expression in neoplasia are highlighted.

The 2019 Havemeyer Workshop brought together researchers and clinicians to discuss the latest information on Equine Asthma and provide future research directions. Current clinical and molecular asthma phenotypes and endotypes in humans were discussed and compared to asthma phenotypes in horses. The role of infectious and non-infectious causes of equine asthma, genetic factors and proposed disease pathophysiology were reviewed. Diagnostic limitations were evident by the limited number of tests and biomarkers available to field practitioners. The participants emphasized the need for more accessible, standardized diagnostics that would help identify specific phenotypes and endotypes in order to create more targeted treatments or management strategies. One important outcome of the workshop was the creation of the Equine Asthma Group that will facilitate communication between veterinary practice and research communities through published and easily accessible guidelines and foster research collaboration., (Copyright © 2020 Couetil, Cardwell, Leguillette, Mazan, Richard, Bienzle, Bullone, Gerber, Ivester, Lavoie, Martin, Moran, Niedźwiedź, Pusterla and Swiderski.)

Background: Flow cytometry (FC) is used increasingly in veterinary medicine for further characterization of hematolymphoid cells. Guidelines for optimizing assay performance and interpretation of results are limited, and concordance of results across laboratories is unknown., Objectives: This study aimed to determine inter-investigator agreement on the interpretation of FC results from split samples analyzed in different laboratories using various protocols, cytometers, and software; and on the interpretation of archived FC standard (FCS) data files contributed by the different investigators., Methods: This was a multicenter observational cross-sectional study. Anticoagulated blood or lymph node aspirate samples from nine client-owned dogs were aliquoted and shipped to participating laboratories. Samples were analyzed with individual laboratory-developed protocols. In addition, FCS files from a set of separate samples from 11 client-owned dogs were analyzed by participating investigators. A person not associated with the study tabulated the results and interpretations. Agreement of interpretations was assessed with Fleiss' kappa statistic., Results: Prolonged transit times affected sample quality for some laboratories. Overall agreement among investigators regarding the FC sample interpretation was strong (κ = 0.86 ± 0.19, P < .001), and for specific categories, ranged from moderate to perfect. Agreement of the lymphoproliferation or other leukocyte sample category from the analysis of the FCS files was weak (κ = 0.58 ± 0.05, P < .001)., Conclusions: Lymphoproliferations were readily identified by FC, but identification of the categories of hematolymphoid neoplasia in fresh samples or archived files was variable. There is a need for a more standardized approach to maximize the enormous potential of FC in veterinary medicine., (© 2020 American Society for Veterinary Clinical Pathology.)

This article describes the indications for sampling of bone marrow, the technical aspects of obtaining marrow core biopsies and aspirates, and the preparation of marrow smears. All aspects are illustrated with clinical cases. The information that can be expected from the pathologist's report of marrow samples is outlined, and the clinical features and prognosis of different types of leukemia are detailed., Competing Interests: Disclosure There was no funding for this review article., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Evolution of indolent to aggressive lymphoma has been described in dogs but is difficult to distinguish from the de novo development of a second, clonally distinct lymphoma. Differentiation of these scenarios can be aided by next generation sequencing (NGS)-based assessment of clonality of lymphocyte antigen receptor genes., Case Presentation: An 8-year-old male intact Mastiff presented with generalized lymphadenomegaly was diagnosed with nodal T zone lymphoma (TZL) based on cytology, histopathology, immunohistochemistry and flow cytometry. Thirteen months later, the dog re-presented with progressive lymphadenomegaly, and based on cytology and flow cytometry, a large B cell lymphoma (LBCL) was diagnosed. Sequencing-based clonality testing confirmed the de novo development of a LBCL and the persistence of a TZL., Conclusions: The occurrence of two distinct lymphoid neoplasms should be considered if patient features and tumor cytomorphology or immunophenotype differ among sequential samples. Sequencing-based clonality testing may provide conclusive evidence of two concurrent and distinct clonal lymphocyte populations, termed most appropriately "composite lymphoma".

The ability to mount adaptive immune responses to a diverse array of pathogens is essential to maintaining the health of an individual. The outcome of adaptive immune responses is influenced by the pool of available lymphocyte antigen receptors. Understanding the composition and dynamics of immune repertoires is hence of relevance to characterizing physiologic immunological processes as well as understanding disease pathogenesis. The dog is increasingly recognized as a model for human disease. The objective of this study was to utilize NGS for comprehensive and unbiased analysis of the IGH repertoire in healthy dogs. First, the IGH locus was searched in silico for previously unidentified genes. Second, IGH transcripts from major lymphoid organs were amplified using a 5'RACE approach without V/J primer bias. Third, amplicons were sequenced on an Illumina MiSeq platform, and data were analyzed using the ARResT/Interrogate platform. Data analysis included V/J usage, V-J pairing biases, isotype frequency, CDR3 diversity, convergent recombination, and public repertoires. The results of this study provide a comprehensive IGH repertoire analysis for healthy dogs. These data will allow further improvement of V/J gene-specific primer sets and will serve as baseline for future studies investigating immune repertoires in health and disease., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Leukemia in dogs is a heterogeneous disease with survival ranging from days to years, depending on the subtype. Strides have been made in both human and canine leukemia to improve classification and understanding of pathogenesis through immunophenotyping, yet classification and choosing appropriate therapy remains challenging. In this study, we assessed 123 cases of canine leukemia (28 ALLs, 24 AMLs, 25 B-CLLs, and 46 T-CLLs) using high-resolution oligonucleotide array comparative genomic hybridization (oaCGH) to detect DNA copy number alterations (CNAs). For the first time, such data were used to identify recurrent CNAs and inclusive genes that may be potential drivers of subtype-specific pathogenesis. We performed predictive modeling to identify CNAs that could reliably differentiate acute subtypes (ALL vs. AML) and chronic subtypes (B-CLL vs. T-CLL) and used this model to differentiate cases with up to 83.3 and 95.8 % precision, respectively, based on CNAs at only one to three genomic regions. In addition, CGH datasets for canine and human leukemia were compared to reveal evolutionarily conserved copy number changes between species, including the shared gain of HSA 21q in ALL and ∼25 Mb of shared gain of HSA 12 and loss of HSA 13q14 in CLL. These findings support the use of canine leukemia as a relevant in vivo model for human leukemia and justify the need to further explore the conserved genomic regions of interest for their clinical impact.

Few studies have evaluated the long-term effects of providing environmental resources to mice. This consideration is important given that mice are often maintained in vivaria for months. We evaluated the effects of providing simple cage resources (wood wool, cotton nesting material, a plastic tunnel, and oat cereal) compared with standard housing (solid-bottom cage with hardwood chips) to group-housed adult male and female C57BL/6 and BALB/c mice (n = 20/sex/strain/group) over 6 mo to determine whether these resources had a lasting effect on animal physiology, anatomy, and behavior. Body weights increased in all groups over time but were proportionately higher in male and female BALB/c mice housed in resource-supplemented environments. Throughout the study, adding environmental resources had no effect on hematology and lymphocyte subsets, fecal corticoid metabolite levels, response to LPS injection, or dendritic spine length or density. Strain- or sex×environmentspecific changes occurred in dark-light activity and thermal nociceptive responses. Dominant agonistic behaviors, abnormal conspecific sexual behaviors, and social nonagonistic behaviors demonstrated sex and strain×environment interactions such that fewer maladaptive social behaviors were noted in mice that were provided with environmental resources. This association was particularly evident in male mice of both strains in resource-supplemented environments. A small but significant increase in brain weight:body weight ratios occurred in mice in resource-supplemented environments. Under the conditions evaluated here, consistent use of simple environmental resources had a positive long-term effect on the behavioral wellbeing of male and female BALB/c and C57BL/6 mice yet minimally affected other aspects of murine physiology and neuroanatomy.

The feline immunodeficiency virus (FIV) shares genomic organization, receptor usage, lymphocyte tropism, and induction of immunodeficiency and increased susceptibility to cancer with the human immunodeficiency virus (HIV). Global distribution, marked heterogeneity and variable host adaptation are also properties of both viruses. These features render the FIV-cat model suitable to explore many aspects of lentivirus-host interaction and adaptation, and to explore treatment and prevention of infection. Examples of fundamental discoveries that have emerged from study in the FIV-cat model concern two-receptor entrance strategies that target memory T-lymphocytes, host factors that restrict retroviral infection, viral strategies for replication in non-dividing cells, and identification of correlates of immunity to the virus. This article provides a brief overview of strengths and limitations of the FIV-cat model for comparative biology and medicine., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Commonly used 11ga or 13ga biopsy needles are relatively large for cats and often preclude successful collection of bone marrow (BM) core biopsies., Objectives: The objective was to compare 15ga to 13ga BM core biopsy ease of collection and specimen quality., Methods: In 10 cats, humeral biopsies obtained with 15ga EZ-IO needles were compared with iliac biopsies obtained with 13ga Jamshidi needles. Body condition, ease of collection, section quality, postprocedure pain, and swelling at biopsy sites were scored. Specimen length on mounted slides was measured and specimens with quality scores of 3-5 out of a maximum value of 5 were considered to be of acceptable diagnostic quality. The distribution of all parameters was assessed by Shapiro-Wilk tests, and differences in parameters were assessed by ANCOVA., Results: There were no significant differences between 15ga and 13ga biopsies, except that the 15ga humeral biopsy was judged to be easier to perform than 13ga iliac biopsy, and there was more severe postbiopsy swelling with 13ga biopsies. Facility score (mean ± SD), section quality score (median ± SD) and specimen length (mm, mean ± SD) were 12.7 ± 2.3, 2.0 ± 1.4, and 6.0 ± 2.1 for 15ga biopsies, respectively, and 8.9 ± 2.4, 1.0 ± 1.8, and 7.5 ± 2.5 for 13ga biopsies, respectively. Three specimens of acceptable quality were obtained with each 15ga and 13ga biopsies., Conclusions: In cats, BM biopsy of the humerus with a 15ga needle is easier and causes less postbiopsy swelling than biopsy of the ilium with a 13ga needle. Sites and needles are equivalent with respect to yielding specimens of acceptable quality. Neither technique consistently captured high-quality specimens., (©2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.)

Septic synovitis is a potentially debilitating and life-threatening disorder in horses. We hypothesized that a universal bacterial real-time PCR (RT-PCR) assay would have improved sensitivity and decreased turn-around time for detection of bacteria in synovial fluid (SF) samples. Forty-eight SF samples were collected from 36 horses that presented to two referral institutions with suspected septic synovitis. Universal RT-PCR, bacterial culture and SF analysis were performed on all samples, and an interpretation on the sample being septic or not was derived by three board certified specialists from the history, clinical assessment and SF characteristics. RT-PCR results were compared to a composite standard comprised of positive culture and interpretation by all three specialists of samples as "septic". For 41 of 48 samples (85%), culture and RT-PCR results were concordant. Compared to the composite standard, 83% of samples were correctly classified by RT-PCR (turn-around time of approximately 4 hours). Relative sensitivity and specificity of RT-PCR were 87% and 72% respectively, and 56% and 86% for culture. Hence, universal RT-PCR was a rapid and highly sensitive test, which may accelerate diagnosis and improve outcome for horses with septic synovitis.

Background: Sternal bone marrow aspiration in dogs is not commonly performed as it is considered technically challenging in smaller dogs. However, the sternum is readily accessible and associated with less pain from aspiration compared with other sites., Objectives: The aim of the study was to investigate feasibility, ease, number of attempts, safety, and sample quality of sternal bone marrow aspirates in small dogs., Methods: Bone marrow aspirates were obtained in a randomized order from 3 sites in 26 clinically healthy Beagles under general anesthesia. Samples were obtained from the sternum using one-inch 20- or 22-gauge hypodermic needles, from the right greater tubercle of the humerus, and the right iliac crest using 18-gauge Illinois needles. The difficulty of each procedure was scored. Two types of bone marrow smears were prepared and reviewed by a pathologist unaware of site of aspiration or dog. The number of particles per slide and overall slide quality were scored. The site of aspiration and the cranial thoracic wall were evaluated at autopsy for evidence of trauma or pneumothorax., Results: The number of attempts and time for bone marrow aspiration were greater for ilium than for sternum or humerus, but the sternum was the easiest to aspirate. Smear quality and particle number were similar for all sites. Neither trauma at the site of aspiration nor pneumothorax were identified., Conclusions: Aspiration of sternal bone marrow with hypodermic needles is feasible and safe in Beagle dogs. Samples equivalent in quality to those from the humerus or ilium can be obtained from clinically normal dogs., (© 2013 American Society for Veterinary Clinical Pathology.)

Background: Commonly used 11 or 13ga needles are relatively large for collection of bone marrow (BM) biopsies from small dogs., Objectives: The aims of this study were to assess ease of BM collection and quality of specimens obtained from small dogs using 13 and 15ga needles and to determine if specimen encasement would improve quality., Methods: Humeral and iliac biopsies obtained from 17 Beagle dogs with a 15ga needle and a power driver were compared with humeral biopsies obtained with a 13ga Jamshidi needle. Ease of collection (scored as 1 [very difficult] to 5 [very easy] for 3 components of collection with scores summed), section quality (scored as 1 [poor] to 5 [good]), and lesions at collection sites were scored. Quality of additional humeral biopsies obtained with a 15ga needle and wrapped in tissue paper prior to fixation was assessed., Results: Use of a 15ga needle to obtain a humeral BM biopsy was significantly easier (mean score ± SD = 13.6 ± 1.7) than obtaining humeral BM using a 13ga needle (11.4 ± 1.6; P < .001) or obtaining iliac BM using a 15ga needle (10.9 ± 2.0, P < .001). Quality of humeral biopsies obtained with a 13ga needle (3.9 ± 1.2) was better than for biopsies of the humerus (1.9 ± 1.3, P < .001) or ilium (1.4 ± 0.6, P < .001) using a 15ga needle. Only sites sampled with a 13ga needle were identifiable grossly after the procedure. In most biopsies, cell density and cellularity were lower when a 15ga needle was used. Paper-wrapping of biopsies did not improve quality., Conclusions: In small dogs, collection of humeral BM biopsies using a 15g needle is feasible and more easily accomplished than collection using a 13ga needle. Hematopoiesis may be underestimated in specimens collected using the smaller needle., (© 2012 American Society for Veterinary Clinical Pathology.)

Background: Primary immune-mediated hemolytic anemia (IMHA) is an important cause of morbidity and mortality in dogs. The mechanisms underlying autoimmune reactivity remain poorly understood., Objective: The aim of this study was to identify membrane proteins of RBCs that could be antigenic in dogs with primary IMHA., Methods: Antibodies were eluted with xylene from RBCs of 12 dogs with IMHA, 4 dogs with anemia due to causes other than IMHA, and 2 healthy dogs. Pooled RBC membrane proteins were prepared from blood of 17 healthy dogs. The eluted antibodies were then analyzed by immunoblotting for interactions with the pooled membrane proteins and autologous plasma. Bands present in the 12 dogs with IMHA but not in the 6 other dogs were considered potential autoantigens and were identified by liquid chromatography followed by tandem mass spectrometry., Results: RBC eluates from all 18 dogs had reactivity against band 3 protein. Antibodies to 6 additional proteins were uniquely identified in dogs with IMHA. Reactivity to calpain, complement component 3, and peroxiredoxin 2 was identified in 8, 8, and 4 of the 12 samples, respectively, from dogs with IMHA, but in none of the samples from the 6 dogs without IMHA., Conclusions: Detection of universal immune reactivity against band 3 protein probably indicates recognition of senescent RBC. Proteins uniquely recognized by antibodies in dogs with IMHA are involved in oxidative stress and apoptosis (calpain), inflammation (complement), and scavenging of reactive oxygen species (peroxiredoxin 2). It remains to be determined if these proteins are important in initiating autoimmunity or if immunoglobulins targeting these proteins develop during IMHA., (© 2012 American Society for Veterinary Clinical Pathology.)

Infection of cats with the feline immunodeficiency virus (FIV) recapitulates many aspects of infection of humans with HIV, including highly activated but ineffectual immune responses. Infected hosts remain seropositive for life, and detection of antibodies is the mainstay of diagnosis. However, to quantify virus for research or prognosis, viral proteins, nucleic acids or enzymes, are typically measured by ELISA, PCR or activity, respectively. While such assays are in wide use, they do not distinguish whole, infectious viral particles from defective or disrupted viruses. Titers of infectious viral particles may be estimated from tissue culture infectious doses or by enumerating cell-associated viral proteins, viral transcriptional activity or formation of syncytia. To analyze the viral proteome and the incorporation of host components into viral envelopes, pure lentiviral preparations are required. Methods for purifying lentiviruses include ultracentrifugation to separate particles by size, mass and/or density; chromatography to separate particles by charge, affinity or size; and additional removal of extraviral proteins and exosomes through subtilisin digestion or immunoaffinity. This article reviews advantages and disadvantages of different approaches to purification of lentiviruses with special reference to suitability for FIV, and highlights effects of purification on immune responses and immune assays., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are common and important infectious disease agents of cats in Canada. Seroprevalence data for FeLV and FIV in various populations of Canadian cats are reviewed and recommendations for testing and management of infections by these viruses in cats in Canada are presented. Retrovirus testing in Canada is infrequent in comparison with the United States, and efforts should be focused on reducing physical and other barriers to testing, and on education of veterinarians, veterinary team members, and cat owners regarding the importance of testing. New test methodologies for FeLV and FIV are emerging, and should be independently evaluated in order to provide practitioners with information on test reliability. Finally, more information is needed on FIV subtypes in Canada to improve diagnostics and vaccines, and to provide information on disease outcomes.

Lymphoma in dogs is a heterogeneous cancer with highly variable prognosis. Many types of canine lymphoma have similar counterparts in the World Health Organization classification of human lymphoid tumors. The most common variant of canine lymphoma is diffuse large B-cell lymphoma, which, if treated with multiagent chemotherapy, has a survival time of approximately 12 months. T-cell lymphomas are more heterogeneous and high- and low-grade variants are common, which necessitates classification beyond B- versus T-cell lineage., (Copyright © 2011 Elsevier Inc. All rights reserved.)

This study assessed the value of polymerase chain reaction (PCR) for making a diagnosis of feline herpesvirus (FHV-1) infection, and for differentiating this from Chlamydophila felis and Mycoplasma spp. infection in a clinical setting in Canada. We compared the frequency of positive FHV-1 PCR test results from 48 clinical cases of ocular disease in cats suspected to be due to FHV-1 between 1 research and 2 commercial laboratories in Canada. We also compared PCR results for Chlamydophila felis and Mycoplasma spp. between the 2 commercial laboratories. The prevalence of FHV-1 infection in the cats ranged from 4% to 21%. The prevalence of Chlamydophila felis was 2% and 17% and the prevalence of Mycoplasma spp. was 11% and 27%. Agreement between FHV-1 culture and PCR results at the research laboratory was substantial (kappa = 0.76). There was slight agreement (kappa < 0.20) between the 3 laboratories for FHV-1 PCR and between the 2 commercial laboratories for both Chlamydophila felis (kappa = 0.2) and Mycoplasma spp. (kappa = 0.07) PCR.

The purposes of this study were to determine the seroprevalence of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infection among cats in Canada and to identify risk factors for seropositivity. Signalment, lifestyle factors, and test results for FeLV antigen and FIV antibody were analyzed for 11 144 cats from the 10 Canadian provinces. Seroprevalence for FIV antibody was 4.3% and seroprevalence for FeLV antigen was 3.4%. Fifty-eight cats (0.5%) were seropositive for both viruses. Seroprevalence varied geographically. Factors such as age, gender, health status, and lifestyle were significantly associated with risk of FeLV and FIV seropositivity. The results suggest that cats in Canada are at risk of retrovirus infection and support current recommendations that the retrovirus status of all cats should be known.

From 1991 to 2003, 24 cases of larval cyathostominosis were diagnosed at postmortem in equids, 15 (63%) from 2001 to 2003. Cases occurred from September to May, the majority from October to December. Median age was 12 mo. Diarrhea, colic, and weight loss were common clinical signs. Hypoalbuminemia and microcytosis were consistent findings.