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.
To describe the prevalence of ocular lesions in cats with newly diagnosed histoplasmosis.
55 client-owned domestic cats.
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.
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).
Detailed ophthalmic examinations should be performed on all cats with diagnosed or suspected histoplasmosis, as ocular involvement and subsequent vision loss are common.
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).
56 healthy adult dogs.
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.
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).
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.
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.
32 client owned dogs with newly diagnosed pulmonary coccidioidomycosis from October 2020 to February 2021.
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.
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.
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.
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.
Blood samples from 30 hens.
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.
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.