Tracing histoplasmosis genomic epidemiology and species occurrence across the USA.

ABSTRACTHistoplasmosis is an endemic mycosis in North America frequently reported along the Ohio and Mississippi River Valleys, although autochthonous cases occur in non-endemic areas. In the United States, the disease is provoked by two genetically distinct clades of Histoplasma capsulatum sensu lato, Histoplasma mississippiense (Nam1) and H. ohiense (Nam2). To bridge the molecular epidemiological gap, we genotyped 93 Histoplasma isolates (62 novel genomes) including clinical, environmental, and veterinarian samples from a broader geographical range by whole-genome sequencing, followed by evolutionary and species niche modelling analyses. We show that histoplasmosis is caused by two major lineages, H. ohiense and H. mississippiense; with sporadic cases caused by H. suramericanum in California and Texas. While H. ohiense is prevalent in eastern states, H. mississipiense was found to be prevalent in the central and western portions of the United States, but also geographically overlapping in some areas suggesting that these species might co-occur. Species Niche Modelling revealed that H. ohiense thrives in places with warmer and drier conditions, while H. mississippiense is endemic to areas with cooler temperatures and more precipitation. In addition, we predicted multiple areas of secondary contact zones where the two species co-occur, potentially facilitating gene exchange and hybridization. This study provides the most comprehensive understanding of the genomic epidemiology of histoplasmosis in the USA and lays a blueprint for the study of invasive fungal diseases.

A single injection of high-concentration buprenorphine significantly reduces food and water intake as well as fecal and urine production in New Zealand White rabbits (Oryctolagus cuniculus).

OBJECTIVE: To evaluate selected gastrointestinal side effects of high-concentration buprenorphine (HCB) in healthy rabbits. ANIMALS: 10 healthy New Zealand White rabbits ranging in body weight between 3.0 and 3.8 kg. METHODS: Eight, 6-month-old, New Zealand White rabbits received a single injection of HCB SC (0.24 mg/kg). The rabbits were previously randomized to receive SC and oral saline as a control. Two rabbits received saline for the purpose of blinding the outcome assessors. Food and water consumption, fecal and urine production, and fecal pellet number were recorded for all rabbits before HCB administration and the 3 days postinjection. RESULTS: A clinically and statistically significant decrease in food and water consumption was observed in rabbits receiving an injection of HCB, compared to rabbits receiving saline. In the 24 hours after injection, HCB-treated rabbits consumed a median of 17 g of food (range, 0 to 82 g), while saline-treated rabbits consumed 122 g of food (31 to 181 g). Rabbits receiving HCB injections also produced significantly less feces both in terms of pellet numbers and overall quantity, along with decreased urine production. CLINICAL RELEVANCE: A single administration of HCB has a clinically significant impact on multiple physiological functions in healthy rabbits. Administration of this drug could potentially worsen clinical signs of anorexia and decrease defecation in healthy rabbits. The effects of HCB on diseased or painful rabbits are not yet known.

Temporal tracheobronchial lymphadenopathy resolution is affected by initial severity and poorly correlated to serologic antibody testing in dogs with pulmonary coccidioidomycosis.

OBJECTIVE: To determine associations between antibody serologic tests and tracheobronchial lymphadenopathy (TBL) in dogs with pulmonary coccidioidomycosis and identify variables associated with time to resolution of TBL. ANIMALS: 32 client owned dogs with newly diagnosed pulmonary coccidioidomycosis from October 2020 to February 2021. METHODS: Prospective cohort study. Thoracic radiographs and anti-Coccidioides spp antibody serology were performed at baseline and once every 3 months until remission or for a maximum of 12 months. Radiographic tracheobronchial lymph node height, length, and area were measured and recorded as ratios via comparison with the length of the T4 vertebral body (LT4) and length of the manubrium. Severity of TBL was also subjectively categorized as mild, moderate, or severe. RESULTS: Tracheobronchial lymphadenopathy was identified in 81% (26/32; 95% CI, 64% to 93%) of dogs. There was no relevant association between TBL presence or severity and antibody serology results. Tracheobronchial lymphadenopathy resolved in 72% (n = 18) of dogs at the 3-month evaluation. The median time to resolution of TBL after initiation of fluconazole was 96 days (range, 72 to 386 days). Univariate analysis identified increasing TBL severity (hazard ratio, 0.40; 95% CI, 0.19 to 0.84; P = .02) and length:LT4 ratio (hazard ratio, 0.41; 95% CI, 0.20 to 0.82; P = .01) as variables associated with reduced probability of resolution of TBL. CLINICAL RELEVANCE: Antibody serologic test results are not clinically useful to predict TBL presence or severity in dogs with pulmonary coccidioidomycosis, and larger tracheobronchial lymph nodes are more likely to take longer to resolve. Resolution of TBL occurs in most dogs within 3 to 6 months after fluconazole administration.

Clinical utility of fungal culture and antifungal susceptibility in cats and dogs with histoplasmosis.

BACKGROUND: Culture can be used for diagnosis and antifungal susceptibility testing in animals with fungal infections. Limited information is available regarding the diagnostic performance of culture and the susceptibility patterns of Histoplasma spp. isolates. HYPOTHESIS/OBJECTIVES: Describe the clinical utility of culture and the susceptibility patterns of Histoplasma spp. isolates causing histoplasmosis in cats and dogs. ANIMALS: Seventy-one client-owned animals, including 33 cats and 19 dogs with proven or probable histoplasmosis. METHODS: Culture was attempted from tissue or fluid samples. Diagnostic performance of culture, cytopathology, and antigen detection were compared with final diagnosis. Susceptibility to antifungal agents was determined for a subset (11 from dogs, 9 from cats) of culture isolates. RESULTS: Culture had a diagnostic sensitivity of 17/33 (52%; 95% confidence interval [CI], 34%-69%) and 15/19 (79%; 95% CI, 61%-97%) and specificity of 6/6 (100%; 95% CI, 54%-100%) and 10/10 (100%; 95% CI, 69%-100%) in cats and dogs, respectively. Culture was not positive in any animal in which cytopathology and antigen testing were negative. Target drug exposure (area under the concentration curve [AUC]/minimum inhibitory concentration [MIC] >25) should be easily achieved for all isolates for itraconazole, voriconazole, or posaconazole. Five of 20 (25%) isolates had fluconazole MIC ≥32 µg/mL and achieving target drug exposure is unlikely. CONCLUSIONS AND CLINICAL IMPORTANCE: Fungal culture did not improve diagnostic sensitivity when used with cytopathology and antigen detection. Susceptibility testing might help identify isolates for which fluconazole is less likely to be effective.

Evaluation of an enzyme immunoassay and immunodiffusion for detection of anti-Histoplasma antibodies in serum from cats and dogs.

BACKGROUND: Histoplasma antigen and anti-Histoplasma antibody detection are used to support the diagnosis of histoplasmosis. There is a paucity of published data on antibody assays. OBJECTIVES: Our primary hypothesis was that anti-Histoplasma immunoglobulin G (IgG) antibody detection using enzyme immunoassay (EIA) will be more sensitive as compared to immunodiffusion (ID). ANIMALS: Thirty-seven cats and 22 dogs with proven or probable histoplasmosis; 157 negative control animals. METHODS: Residual stored sera were tested for anti-Histoplasma antibodies using EIA and ID. Results of urine antigen EIA were reviewed retrospectively. Diagnostic sensitivity was calculated for all three assays and compared between immunoglobulin G (IgG) EIA and ID. The diagnostic sensitivity of urine antigen EIA and IgG EIA, interpreted in parallel, was reported. RESULTS: Sensitivity of IgG EIA was 30/37 (81.1%; 95% confidence interval [CI], 68.5%-93.4%) in cats and 17/22 (77.3%; 95% CI, 59.8%-94.8%) in dogs. Diagnostic sensitivity of ID was 0/37 (0%; 95% CI, 0%-9.5%) in cats and 3/22 (13.6%; 95% CI, 0%-28.0%) in dogs. Immunoglobulin G EIA was positive in all animals (2 cats and 2 dogs) with histoplasmosis but without detectable antigen in urine. Diagnostic specificity of IgG EIA was 18/19 (94.7%; 95% CI, 74.0%-99.9%) in cats and 128/138 (92.8%; 95% CI, 87.1%-96.5%) in dogs. CONCLUSION AND CLINICAL IMPORTANCE: Antibody detection by EIA can be used to support the diagnosis of histoplasmosis in cats and dogs. Immunodiffusion has an unacceptably low diagnostic sensitivity and is not recommended.

Evaluation of serum 25-hydroxyvitamin D, C-reactive protein, and haptoglobin as biomarkers in dogs newly diagnosed with histoplasmosis.

BACKGROUND: Serum 25-hydroxyvitamin (OH)D, C-reactive protein (CRP), and haptoglobin are useful biomarkers in various infectious diseases and inflammatory disorders in dogs, but their utility in histoplasmosis is unknown. OBJECTIVE: Determine if serum 25(OH)D, CRP, and haptoglobin concentrations are different in dogs with histoplasmosis compared to healthy controls and whether serum globulin, albumin, CRP, or haptoglobin are associated with 25(OH)D concentration. ANIMALS: Twenty-two client-owned dogs (histoplasmosis, n = 12; controls, n = 10). METHODS: Prospective case-control study. Dogs with histoplasmosis were categorized as pulmonary, disseminated, or gastrointestinal (GI) tract. Serum 25(OH)D was measured using modified high-performance liquid chromatography (HPLC). Serum CRP and haptoglobin were measured with ELISA assays. RESULTS: Dogs with histoplasmosis were grouped as disseminated (n = 8) and GI tract (n = 4). No dogs had pulmonary tract involvement alone. Dogs with histoplasmosis (median, interquartile range [IQR]; 11.6 ng/mL, 16.8) had lower serum 25(OH)D concentrations than controls (35.7 ng/mL, 17.6; P < .001). Serum CRP and haptoglobin concentrations were higher in dogs with histoplasmosis (CRP: median, IQR; 63.5 mg/L, 37.1 and haptoglobin: 459.7 mg/dL, 419.6) than controls (CRP: 1.9 mg/L, 2; P < .001 and haptoglobin: 85.5 mg/dL, 106.7; P = .003). Serum 25(OH)D concentration was positively associated with fold change in serum albumin concentration (ρ = 0.77; P < .001), and negatively associated with fold change in serum globulin (ρ = -0.61; P = .003) and CRP concentrations (ρ = -0.56; P = .01). CONCLUSION AND CLINICAL IMPORTANCE: Assay of serum 25(OH)D, CRP, and haptoglobin could have clinical value in dogs with histoplasmosis.

Clinical utility of an immunoglobulin A-based serological panel for the diagnosis of chronic enteropathy in dogs.

BACKGROUND: A panel of IgA-based serologic assays might aid in the diagnosis of chronic enteropathy (CE) in dogs, a syndrome encompassing conditions such as food-responsive enteropathy, immunosuppressant-responsive enteropathy, and inflammatory bowel disease (also referred to as chronic inflammatory enteropathy). However, it is unclear whether these biomarkers discriminate between CE and other types of primary intestinal disorders. OBJECTIVES: To evaluate a diagnostic panel that measures serum concentrations of IgA directed against OmpC (ACA), canine calprotectin (ACNA), and gliadin-derived peptides (AGA) in dogs with well-characterized intestinal diseases. ANIMALS: Fifty-five dogs with primary intestinal disease. METHODS: Serum ACA, ACNA, and AGA concentrations were measured in 30 dogs with CE and 25 dogs with other intestinal diseases (non-CE population), including histoplasmosis, parasitism, E. coli-associated granulomatous colitis, and lymphoma. Serum IgA concentrations were compared among populations, and sensitivities and specificities were calculated using laboratory-provided cut-points. RESULTS: Twenty-six of 30 (87%) CE dogs and 21 of 25 (84%) non-CE dogs had abnormal concentrations (intermediate or high) of at least 2 markers; these proportions were not significantly different (P = .99). A serum ACA concentration ≥15 EU/mL was 86.7% (95% confidence interval [CI], 69.3%-96.2%) sensitive and 24.0% (95% CI, 9.4%-45.1%) specific for CE diagnosis. High AGA concentrations were observed in 16 of 25 (64%) non-CE dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: The evaluated serologic markers were poorly specific for CE diagnosis, which raises concerns that their use in clinical practice might lead to misdiagnoses and delayed or even detrimental treatments in dogs with non-CE intestinal diseases.

In vitro effect of hydroxyethyl starch on coagulation in dogs as assessed by dynamic viscoelastic coagulometry.

OBJECTIVE: To evaluate the effect of 6% hydroxyethyl starch (HES) 670/0.75 and 6% HES 130/0.4 dilution of canine whole blood on coagulation using dynamic viscoelastic coagulometry (DVC). ANIMALS: 56 healthy adult dogs. PROCEDURES: 2 blood samples were obtained from each dog and randomized to 1 of 7 groups-undiluted or 2 dilutions (1:3 or 1:10) of 3 different fluids: saline (0.9% NaCl) solution, 6% HES 670/0.75, or 6% HES 130/0.4. Dilutions were calculated to simulate approximately a 10- or 30-mL/kg body weight IV bolus of each fluid. DVC was performed on each sample. Coagulation parameters compared between groups included clot rate (CR), platelet function (PF), and activated clotting time. RESULTS: Dilution with saline solution did not significantly affect coagulation, while dilution with HES 670/0.75 and HES 130/0.4 caused a dose-dependent significant decrease in CR (1:3 HES 670/0.75, P = 0.007; 1:10 HES 670/0.75, P = 0.002; 1:3 HES130/0.4, P < 0.0001; and 1:10 HES 130/0.4, P = 0.0003) and PF (1:3 HES 670/0.75, P < 0.0001; 1:10 HES 670/0.75, P < 0.0001; 1:3 HES130/0.4, P < 0.0001; and 1:10 HES 130/0.4, P = 0.0015). CLINICAL RELEVANCE: Dilution of canine blood with HES 670/0.75 and HES 130/0.4, at clinically relevant doses (10 and 30 mL/kg), led to significant hypocoagulability beyond dilutional effect. This was, in part, due to impaired PF, which was significantly greater with HES 670/0.75. Further research using DVC to assess the effects of HES on coagulation in dogs, ideally with clinical conditions warranting HES administration, is needed.

Prevalence of ocular lesions in cats newly diagnosed with histoplasmosis: 55 cases (2015-2022).

OBJECTIVE: To describe the prevalence of ocular lesions in cats with newly diagnosed histoplasmosis. ANIMALS: 55 client-owned domestic cats. PROCEDURES: As part of this prospective case series, cats diagnosed with histoplasmosis between the years 2015 and 2020 underwent complete ophthalmic examinations by a board-certified veterinary ophthalmologist prior to the initiation of antifungal treatment. Histoplasmosis was diagnosed by consistent clinical findings and identification of Histoplasma yeast on pathology or by the use of a commercially available enzyme immunoassay to detect Histoplasma antigen in urine. RESULTS: Of the 55 cats, 45 (82%; 95% CI, 72% to 92%) had signs of active anterior, posterior, or panuveitis. The most common lesions were identified in the posterior portion of the globe and included chorioretinitis and partial retinal detachments (44/55 [80%; 95% CI, 69% to 90%] cats). CLINICAL RELEVANCE: Detailed ophthalmic examinations should be performed on all cats with diagnosed or suspected histoplasmosis, as ocular involvement and subsequent vision loss are common.

Invasive fungal rhinitis with adnexal involvement caused by Histoplasma capsulatum in a cat from a non-enzootic location.

CASE SUMMARY: This report describes a cat with a rare form of histoplasmosis: invasive rhinitis with adnexal involvement, mimicking disease more commonly caused by cryptococcosis or aspergillosis. This case is especially noteworthy as it was from an area where histoplasmosis is not enzootic. RELEVANCE AND NOVEL INFORMATION: Invasive fungal rhinitis causes significant morbidity in cats. Diagnostic investigation of more common pathogens includes detection of fungal antigen (Cryptococcus) or antifungal antibodies (Aspergillus). This case demonstrates that histoplasmosis can present as chronic nasal disease in cats. Histoplasma antigen testing provides a non-invasive diagnostic option. Moreover, this case serves as a reminder that histoplasmosis can affect cats anywhere, even in non-enzootic areas.

Evaluation of a novel monoclonal antibody-based enzyme immunoassay for detection of Histoplasma antigen in urine of dogs.

BACKGROUND: Commercially available, noninvasive testing options for histoplasmosis are limited outside of the United States. OBJECTIVES: To describe the diagnostic performance of a novel Histoplasma antigen enzyme immunoassay (IM EIA) for the diagnosis of histoplasmosis in dogs. ANIMALS: Twenty dogs with histoplasmosis, 79 dogs without histoplasmosis, and 11 unclassified dogs providing 202 urine samples. METHODS: This a prospective study using stored urine samples. Samples were analyzed with the IM EIA and with the commercially available Histoplasma antigen EIA (MV EIA). Dogs were classified based on final proven diagnosis and performance of the IM EIA was described and compared with the MiraVista enzyme immunoassay (MV EIA). RESULTS: The diagnostic sensitivity (DSe), specificity (DSp), and accuracy (DAc) of the IM EIA were 70% (51%-89%), 99% (97%-100%), and 93% (81%-100%), respectively. The DSe, DSp, and DAc for the MV EIA were 95% (85%-100%), 99% (97%-100%), and 98% (95%-100%), respectively. The area under the receiver operator characteristic curve was significantly smaller for IM EIA (0.87) as compared with MV EIA (0.97, P = .03). This was primarily due to 6 false negative IM EIA results, 4 from dogs with disease localized to the gastrointestinal tract. The MV EIA was positive in 5/6 of these dogs. CONCLUSIONS AND CLINICAL IMPORTANCE: The IM EIA might be useful for the diagnosis of disseminated histoplasmosis in dogs, but clinical usefulness will be limited in dogs with histoplasmosis localized to the GI tract.

Clinical pharmacokinetics and outcomes of oral fluconazole therapy in dogs and cats with naturally occurring fungal disease.

This multi-institutional study was designed to determine the clinical pharmacokinetics of fluconazole and outcomes in client-owned dogs (n = 37) and cats (n = 35) with fungal disease. Fluconazole serum concentrations were measured. Pharmacokinetic analysis was limited to animals at steady state (≥72 hr of treatment). The mean (range) body weight in 31 dogs was 25.6 (2.8-58.2) kg and in 31 cats was 3.9 (2.4-6.1) kg included in pharmacokinetic analyses. The dose, average steady-state serum concentrations (CSS ), and oral clearance in dogs were 14.2 (4.5-21.3) mg/kg/d, 26.8 (3.8-61.5) µg/mL, and 0.63 ml min-1  kg-1 , respectively, and in cats were 18.6 (8.2-40.0) mg/kg/d, 32.1 (1.9-103.5) µg/mL, and 0.61 ml min-1  kg-1 , respectively. Random inter-animal pharmacokinetic variability was high in both species. Two dogs had near twofold increases in serum fluconazole when generic formulations were changed, suggesting lack of bioequivalence. Median CSS for dogs and cats achieving clinical remission was 19.4 and 35.8 µg/ml, respectively. Starting oral doses of 10 mg/kg q12h in dogs and 50-100 mg total daily dose in cats are recommended to achieve median CSS associated with clinical remission. Due to the large pharmacokinetic variability, individualized dose adjustments based on CSS (therapeutic drug monitoring) and treatment failure should be considered.

Dynamic viscoelastic coagulometry of blood obtained from healthy chickens.

OBJECTIVE: To assess feasibility of the use of a dynamic viscoelastic coagulometer on chicken blood and compare coagulation variables for fresh whole blood and sodium citrate-preserved whole blood as well as effects of 3 coagulation activators on blood from chickens. SAMPLE: Blood samples from 30 hens. PROCEDURES: Chickens were allowed to rest undisturbed for 1 hour. A blood sample was collected from an ulnar vein; 1.4 mL was analyzed immediately, and 1.8 mL was mixed with sodium citrate and subsequently recalcified and analyzed. A separate coagulation activator (glass beads, kaolin clay, or tissue factor) was in each of the 2 channels of the analyzer. Chickens were allowed a 1-hour rest period, and another blood sample was collected from the contralateral ulnar vein; it was processed in the same manner as for the first sample, except both channels of the analyzer contained the same coagulation activator. RESULTS: Compared with fresh samples, citrated samples had higher values for activated clotting time and platelet function and lower clotting rates. Intra-assay coefficients of variation of coagulation profiles for citrated samples were markedly greater than the limit of 10%, whereas values for fresh samples were close to or < 10%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that use of a dynamic viscoelastic coagulometer on chicken blood was feasible and that analysis of fresh whole blood from healthy chickens provided results with less variability than did analysis of citrated blood. Samples preserved with sodium citrate were associated with significant relative hypocoagulability, compared with results for fresh blood.

Novel canine anti-Coccidioides immunoglobulin G enzyme immunoassay aids in diagnosis of coccidioidomycosis in dogs.

The diagnosis of coccidioidomycosis (CM) in dogs is typically based on clinical presentation, serology, and (less frequently) spherule identification. Agar gel immunodiffusion (AGID) is the most commonly employed serological method, but AGID is slow (requiring up to a week for titer). A Coccidioides antigen enzyme immunoassay (EIA) is also available; however, sensitivity is low in CM dogs. An antibody EIA was developed to detect canine immunoglobulin G (IgG) reacting to Coccidioides antigens. Serum was evaluated from dogs with pathology proven CM and/or AGID positive CM, as well as dogs with histoplasmosis, blastomycosis, non-fungal infections, or healthy dogs. A standard curve was used to convert optical density (OD) values into EIA units (EU). Serum and urine samples from CM dogs were also tested in the antigen EIA. Sensitivity and specificity for IgG were 89.2% and 97.2%, respectively, upon evaluation of dogs with proven or probable CM and control dogs. Cross-reactivity was observed in 7.7% and in 6.4% of dogs with histoplasmosis or blastomycosis, respectively. The antigen EIA alone was insensitive (33.8%). Combined IgG and antigen testing increased sensitivity to 93.2%, as three dogs were IgG-negative but had detectable serum or urine antigen. In 22 dogs with proven CM, sensitivity was statistically similar for antibody EIA and AGID (86% and 73%; P = .487). The MiraVista® canine Coccidioides antibody IgG EIA may aid in the diagnosis of CM by improving turnaround time with comparable sensitivity to AGID. Serial or concurrent testing by antibody and antigen EIAs may be beneficial when screening dogs for CM.

Feline histoplasmosis presenting with bone and joint involvement: clinical and diagnostic findings in 25 cats.

OBJECTIVES: The aim of this study was to describe clinical and diagnostic findings in cats with bone and joint disease associated with histoplasmosis. METHODS: Medical records from between 2011 and 2017 were reviewed. Inclusion criteria required: (1) diagnosis of histoplasmosis by cytology, histology, urine or serum Histoplasma antigen testing, or culture; and (2) lameness or joint effusion as a presenting complaint or physical examination finding. RESULTS: Twenty-five cases met the inclusion criteria. Four had incomplete records, but available data were included when applicable. Lameness was a presenting complaint in 17/21 cats and was the only complaint in 9/21 cats. Initial diagnosis was made by cytology in 22/25 cats and by culture, urine antigen and necropsy in one case each. Diagnostic cytology samples included synovial fluid (n = 13), lymph node (n = 5), skin (n = 2), lung (n = 1) and bone (n = 1). Two additional cases had synovial fluid examined but no organisms present. Inflammation was present in all synovial fluid samples examined. Biopsy was obtained in two cats and histologic diagnoses included osteomyelitis with no infectious organisms identified and severe lymphoplasmacytic synovitis suggestive of feline periosteal proliferative polyarthritis. Histoplasma urine antigen test was positive in 7/12 cats. CONCLUSIONS AND RELEVANCE: Inflammatory arthritis is common in cats with histoplasmosis, with lameness a common presenting complaint. Organisms are found in synovial fluid cytology in most cases. If not, appropriate additional diagnostics must be pursued.

A monoclonal antibody-based urine Histoplasma antigen enzyme immunoassay (IMMY®) for the diagnosis of histoplasmosis in cats.

BACKGROUND: An in-house Histoplasma urine antigen test for cats might be desirable in certain situations. OBJECTIVE: To validate and compare the diagnostic performance of a monoclonal antibody-based IMMY urine Histoplasma antigen enzyme immunoassay (IMMY EIA) to the commercially available urine Histoplasma antigen enzyme immunoassay (MiraVista Diagnostics, MV EIA). ANIMALS: One hundred ninety-three urine samples from 105 client-owned and purpose-bred research cats. METHODS: Cats were classified as Histoplasma positive or negative based on diagnostic investigation. The IMMY EIA and MV EIA were performed on all urine samples. Correlation and agreement between the assays were determined. Diagnostic performance was determined and compared between assays. RESULTS: The IMMY EIA, with a 0.25 ng/mL diagnostic cutoff, provided a diagnostic sensitivity (DSe), diagnostic specificity (DSp), and diagnostic accuracy (DAc) of 89% (95% confidence interval [CI]; 73%-97%), 80% (67%-89%), and 83% (74%-90%), respectively. The IMMY EIA, with a 1.1 ng/mL diagnostic cutoff, provided a DSe, DSp, and DAc of 77% (95% CI 60%-90%), 97% (88%-100%), and 89% (81%-95%), respectively. The MV EIA provided a DSe, DSp, and DAc of 94% (95% CI 81%-99%), 97% (89%-100%), and 96% (90%-99%), respectively. Moderate overall agreement was found between MV EIA and IMMY EIA using the 0.25 ng/mL cut-off (к = 0.44; 95% CI 0.31-0.57) and the 1.1 ng/mL cut-off (к = 0.43, 95% CI, 0.31-0.56). CONCLUSIONS AND CLINICAL IMPORTANCE: The IMMY EIA might be useful as a diagnostic test for histoplasmosis in cats. Further modifications of the IMMY EIA are required to achieve the diagnostic performance of the MV EIA.

Pretreatment Histoplasma capsulatum urine enzymatic immunoassay concentrations do not correlate with outcome but may be influenced by renal function in cats with histoplasmosis.

OBJECTIVES: The objective of this study was to determine if urine Histoplasma antigen (HAg) enzyme immunoassay (EIA) concentrations at the time of diagnosis and prior to the administration of antifungal agents are predictive of outcome for cats infected with Histoplasma capsulatum and to determine if compromised renal function affects urine HAg EIA measurements. METHODS: Medical records at four institutions were searched to identify cats diagnosed with histoplasmosis between April 2012 and December 2015. Pretreatment urine Histoplasma EIA values were recorded, along with patient signalment, serum creatinine concentration, urine specific gravity, site(s) of infection and survival data. RESULTS: Pretreatment urine HAg EIA measurements were available for 50 cats, and ranged from 0-19.1 ng/ml (median 6.3 ng/ml). Thirty-five cats were alive at day 180, 12 had died or were euthanized (median survival time 24 days; range 2-124 days) and three were lost to follow-up. The median urine HAg EIA at the time of diagnosis for cats alive at 6 months was 5 ng/ml (range 0-19.1); this was similar to findings for the non-survivors (median 7.29 ng/ml; range 0.78-19.1; P = 0.54). Surviving cats were significantly younger (mean age 6.9 years) than non-survivors (mean age 9.9 years; P = 0.03) but median body weights (3.8 kg vs 3.6 kg) and rates of pulmonary involvement (22/35 vs 9/12) were similar for the two groups. Median urine HAg EIA concentration was lower in cats with evidence of renal compromise than cats with acceptable renal function (0.54 ng/ml vs 7.2 ng/ml; P <0.013). CONCLUSIONS AND RELEVANCE: Urine HAg EIA concentrations at the time of diagnosis are not predictive of outcome in cats with histoplasmosis and should not be used as a prognostic indicator in this species. Renal function may influence urine HAg EIA concentrations in cats; further investigation is needed to see if concurrent kidney disease impacts test sensitivity.

Clinical signs, treatment, and prognostic factors for dogs with histoplasmosis.

OBJECTIVE To determine the clinical manifestations of histoplasmosis in a large sample of dogs, compare outcomes achieved with fluconazole versus itraconazole, and identify variables available at the time of diagnosis with prognostic value. DESIGN Retrospective case series with nested cohort study. ANIMALS 79 dogs with confirmed histoplasmosis evaluated at 2 veterinary teaching hospitals from 1999 through 2015. PROCEDURES Medical records were reviewed and data extracted regarding clinical signs at evaluation, physical examination findings, clinical laboratory values, other diagnostic test results, treatments, and outcomes. Data were compared between antifungal agents used (fluconazole or itraconazole) and between other variables. RESULTS Various breeds were represented. Working and herding breeds had mostly disseminated histoplasmosis, and toy breeds had mostly the gastrointestinal form. The diagnosis was often achieved with noninvasive techniques, such as cytologic evaluation of rectal scrape samples (n = 24) or blood films (15). Clinical remission was achieved in 16 of 25 (64%) dogs receiving fluconazole and 17 of 24 (71%) dogs receiving itraconazole. No differences were identified between antifungal agents in survival, clinical remission, or disease relapse rates. Identified negative prognostic factors included Great Pyrenees breed, dyspnea, need for oxygen supplementation, icterus, palpable abdominal organomegaly, anemia, thrombocytopenia, hypercalcemia, high serum alkaline phosphatase activity, and hyperbilirubinemia, whereas diarrhea was a positive prognostic factor. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that histoplasmosis should be considered in a sick dog of any breed in an endemic area. Clinical signs may be nonspecific. Diagnosis may often be possible with noninvasive and inexpensive tests. Either fluconazole or itraconazole may be an effective treatment option.

Candidate prognostic indicators in cats with histoplasmosis treated with antifungal therapy.

Objectives The aim of this study was to retrospectively identify candidate prognostic indicators in cats with histoplasmosis treated with antifungal therapy. Methods Medical records of cats diagnosed with histoplasmosis were reviewed. Candidate prognostic indicators were assessed for an association with survival to hospital discharge and survival to 1 and 6 months after diagnosis. Potential indicators included easily obtained data at the time of the initial hospital visit derived from cat signalment, historical information, physical examination, laboratory data, form of disease and initial treatment. Results Approximately 88% of cats survived to discharge, with 77% and 67% surviving to 1 and 6 months, respectively. Clinical variables significantly associated with death at more than one outcome time point included the presence of dyspnea, adventitial lung sounds, fungemia, neurologic disease, neutropenia, lymphopenia, multiple cytopenias (anemia, neutropenia, thrombocytopenia), hyperbilirubinemia and increased creatinine kinase activity. Cats that did not survive were more likely to have received corticosteroids, oxygen supplementation and required hospitalization. In addition, cats that did not survive required significantly longer hospitalization. There was no significant difference between initial antifungal drug and survival. Conclusions and relevance Potential prognostic indicators were associated with more severe respiratory, hepatic, hematologic or neurologic disease. Prospective investigation concerning clinical indicators of disease severity of these body systems is indicated.

Normal reference intervals and the effects of sample handling on dynamic viscoelastic coagulometry (Sonoclot) in healthy adult horses.

OBJECTIVE: To determine reference intervals and the effect of sample agitation and rest time on Sonoclot analysis in healthy adult horses. DESIGN: Original prospective study. SETTING: University veterinary medical teaching hospital. ANIMALS: Sixty healthy adult horses. INTERVENTIONS: Blood was collected for assessment of complete blood count, serum biochemical analysis, and Sonoclot analysis. MEASUREMENTS AND MAIN RESULTS: Horses were determined to be healthy based upon physical examination, CBC, and serum biochemistry analysis. Blood was analyzed in a glass bead-containing cuvette using the Sienco Sonoclot analyzer following 2 rest periods (30 mins and 240 min) and with 2 sample handling interventions (agitated and nonagitated), to obtain values for clot rate, time-to-peak, activated clotting time, and platelet function. This study failed to detect a significant difference when a rest time of 30 minutes was compared with 240 minutes, but based on wide limits of agreement the 2 rest times were not considered interchangeable. Agitation at both rest times significantly affected all Sonoclot analyses leading to changes indicative of hypercoagulability. CONCLUSIONS: Sample agitation and rest time should be taken into consideration when developing preanalytical guidelines for Sonoclot analysis in horses. Calculated reference intervals were relatively wide. Further research is needed to evaluate the clinical utility of Sonoclot analysis in horses.