Epistaxis and Facial Swelling Due to Nasal Blastomycosis in a Cat.

A 5 yr old castrated male domestic longhair was examined because of left-sided facial swelling and epistaxis. Head computed tomography with contrast identified a mass within the left nasal cavity and multifocal regions of nasal bone osteolysis. Histopathology of nasal mass biopsies and cytology of the facial swelling revealed pyogranulomatous inflammation due to Blastomyces dermatitidis. The cat experienced resolution of clinical signs following 8 mo of treatment with itraconazole. Although rare, clinicians should include blastomycosis on the differential diagnoses list of infectious causes for feline nasal disease if within an endemic area.

Detection of Blastomyces gilchristii via metagenomic sequencing in outbreak-associated soils.

Cases of blastomycosis, a serious fungal disease globally rare but endemic to North America, can appear both sporadically and in outbreaks. Tracing these outbreaks to their environment has traditionally used culturing and polymerase chain reaction. Here, we present our method for metagenomic detection of Blastomyces in a 2015 outbreak soil sample from central Wisconsin. By sequencing this sample to multiple depths, we simulated the minimum required depth to detect Blastomyces in this outbreak. Our methods and recommendations can be used to identify the sources of blastomycosis during outbreaks and to learn about the ecology of Blastomyces.

UTILITY OF URINE ANTIGEN TESTING FOR DIAGNOSIS OF BLASTOMYCOSIS IN NONDOMESTIC FELIDS.

Blastomycosis caused by the fungus Blastomyces dermatitidis has been reported to cause disease in numerous species of nondomestic felids. Diagnosis of blastomycosis in domestic species often relies on the combination of clinical signs, radiographic findings, and commercial urinary antigen testing. In this report, the sensitivity, specificity, and positive and negative predictive values for urine blastomyces antigen testing for use in nondomestic felids were examined and compared with findings on postmortem examination. The study showed a sensitivity of 100%, specificity of 91.86%, positive predictive value of 50%, and negative predictive value of 100% for urine antigen testing. Furthermore, radiographic and hematologic findings were compared with those of animals diagnosed with blastomycosis. Radiographic evidence consistent with blastomycosis was found in those animals diagnosed via urine antigen testing, but no significant differences in plasma biochemistry parameters between diseased and nondiseased animals were found. This study provides evidence that a positive blastomycosis antigenuria test result should be combined with other diagnostic methods to confirm the presence of infection with B. dermatitidis, whereas a negative antigenuria test result is 100% effective in predicting the absence of disease.

Negative Antigenuria in a Dog with Suspected Central Nervous System Localized Blastomycosis.

A 7 yr old female spayed mixed-breed dog was presented for a 1 wk history of neck pain and pelvic limb weakness. Examination revealed nonambulatory paraparesis and thoracolumbar hyperesthesia. MRI revealed extensive intramedullary T2-weighted/short tau inversion recovery hyperintensity and diffuse severe T1-post contrast meningeal enhancement of the thoracolumbar spinal cord. An L5-L6 cerebrospinal fluid sample revealed a suppurative pleocytosis (81% neutrophils, total protein 4362.5 mg/dL and nucleated cell count 352,000/µL). While awaiting the results of infectious disease testing, the dog was treated for suspected meningoencephalitis of unknown etiology with corticosteroids, cyclosporine, and a cytarabine arabinoside infusion. The dog neurologically declined and was started on broad-spectrum antibiotics. The dog continued to decline despite antibiotics, and infectious disease titers subsequently revealed serum antibody positivity for blastomycosis. The dog was then referred to a multispecialty referral hospital and was treated with amphotericin B followed by fluconazole. Prednisone was continued at anti-inflammatory doses. Urine blastomycosis antigen testing was submitted for subsequent disease monitoring but was negative. Five months after presentation the dog was clinically doing well with no identifiable neurologic deficits. This case demonstrates that neurologic blastomycosis may have negative urine antigen concentrations in some dogs and that other diagnostic modalities should be pursued when central nervous system fungal disease is suspected.

Disseminated blastomycosis in a 1-year-old, male golden retriever-poodle crossbred dog.

A 1-year-old male golden retriever-poodle crossbred dog was brought to a veterinary clinic with a 1-month travel history to Muskoka, Ontario and a 1-week history of left eye irritation and ocular discharge. Ophthalmic examination and blood analysis revealed bilateral uveitis with a normal complete blood (cell) count and biochemistry panel. Symptomatic treatment was administered with no improvement observed and the dog returned 2 weeks later for assessment of a draining swelling of the left hind 4th digit. Clinical examination of thoracic radiographs and abdominal ultrasound showed evidence of disseminated blastomycosis characterized by pulmonary lesions, and multifocal lymphadenopathy. Biopsy of the draining lesion and cytological examination of an enlarged lymph node established diagnosis. The dog was started on a standard antifungal treatment protocol (itraconazole) but returned after 11 d of treatment with neurological signs including ataxia, paraparesis, left head tilt, and compulsive turning. Humane euthanasia was chosen and the diagnosis was confirmed at postmortem examination.

Blastomycose disséminée chez un chien croisé golden retriever-caniche mâle de 1 an. Un chien croisé golden retriever-caniche mâle âgé d'un an a été amené à une clinique vétérinaire avec un historique de voyage d'un mois à Muskoka, en Ontario et une histoire d'irritation de l'oeil gauche et d'écoulement oculaire d'une semaine. L'examen ophtalmologique et l'analyse sanguine ont révélé une uvéite bilatérale avec une numération globulaire complète et un bilan biochimique normaux. Un traitement symptomatique a été administré sans amélioration observée et le chien est revenu 2 semaines plus tard pour l'évaluation d'une enflure drainante du 4e doigt postérieur gauche. L'examen clinique des radiographies thoraciques et de l'échographie abdominale a montré des signes de blastomycose disséminée caractérisée par des lésions pulmonaires et une lymphadénopathie multifocale. Une biopsie de la lésion drainante et un examen cytologique d'un noeud lymphatique augmenté de volume ont permis d'établir le diagnostic. Le chien a débuté un protocole de traitement antifongique standard (itraconazole) mais est revenu après 11 jours de traitement avec des signes neurologiques, notamment ataxie, paraparésie, inclinaison de la tête à gauche et tournis compulsif. L'euthanasie sans cruauté a été choisie et le diagnostic a été confirmé lors de l'autopsie.(Traduit par Dr Serge Messier).

Mandibular Blastomycosis in a 5-Year-Old Dog.

A case of localized oral mandibular blastomycosis is described in a five-year-old dog. Complete resolution of clinical signs and oral radiographic changes were seen following itraconazole therapy at 5 mg/kg/day for four and a half months. The patient remained free of Blastomyces at the one year follow up based on the Mira Vista Blastomyces urine antigen test by EIA (Enzyme Immunoassay)a. A literature review of localized blastomycosis cases in humans and dogs was performed, available diagnostic tests evaluated, and treatment comparisons made.

Ocular findings in cats with blastomycosis: 19 cases (1978-2019).

OBJECTIVE: To document ocular findings in cats with blastomycosis. ANIMALS: 35 cats with blastomycosis. PROCEDURES: Medical records from 1978 through 2019 were reviewed to identify cats with confirmed Blastomyces infection. Cats were grouped as having or not having ocular involvement. Clinical signs, histopathologic findings, and response to treatment were evaluated. RESULTS: 21 of the 35 (60%) cats with confirmed blastomycosis had ocular abnormalities. Two of 21 cats with ocular abnormalities also had systemic hypertension and were excluded. Of the remaining 19 cats, 15 (79%) had bilateral ocular signs. Ten (53%) cats had inflammatory ocular lesions, and 9 (47%) had neuro-ophthalmic abnormalities. Six of the 19 (32%) cats appeared to be completely blind, and 5 (26%) appeared to be unilaterally blind. For the 10 cats with inflammatory ocular lesions, the most common lesions were anterior uveitis (9/20 eyes), active chorioretinitis (6/20 eyes), and retinal detachment (4/20 eyes). For the 9 cats with neuro-ophthalmic abnormalities, the most common abnormalities were a negative menace or tracking response (10/18 eyes) and negative pupillary light response (4/18 eyes). CLINICAL RELEVANCE: Results suggested that ocular involvement is common in cats with blastomycosis and that both inflammatory lesions and neuro-ophthalmic abnormalities can be seen. Blastomycosis should be considered in the differential diagnosis for cats with anterior uveitis, posterior segment inflammation, or neuro-ophthalmic abnormalities, and a complete ophthalmic examination should be performed in all cats with confirmed or suspected blastomycosis.

Serum 25-hydroxyvitamin D concentrations and mortality in dogs with blastomycosis.

Blastomycosis is a prominent fungal disease in the United States. Vitamin D status has been found to be altered in critical illness and various infectious diseases. The objectives of this study were to compare serum 25-hydroxyvitamin D (25[OH]D) concentrations in dogs with blastomycosis and healthy controls, to assess the change in serum 25(OH)D concentrations in dogs with blastomycosis after 30 days of treatment, and to determine if baseline serum 25(OH)D concentrations in dogs with blastomycosis were associated with in-hospital, 30-day, or end-of-study mortality. In this prospective cohort study, 19 dogs newly diagnosed with blastomycosis had serum 25(OH)D concentrations measured with a commercially available validated radioimmunoassay at the time of diagnosis and 30 days after start of treatment. These values were compared to 24 healthy control dogs. Serum 25(OH)D concentrations at the time of diagnosis were lower in dogs with blastomycosis (median, 203 nmol/L; range, 31-590 nmol/L) than in clinically healthy control dogs (259.5 nmol/L, 97-829 nmol/L; P = 0.01). Despite clinical improvement, there was no significant change in serum 25(OH)D concentrations from baseline to 30-day follow-up. Dogs with baseline serum 25(OH)D concentrations <180.5nmol/L had a greater odds of death during hospitalization (odds ratio [OR], 15.0; 95% confidence interval [CI], 1.4-191.3; P = 0.04) and at 30 days follow-up (OR, 30.0; 95% CI, 2.5-366.7; P = 0.006). These findings highlight the need for further studies evaluating the prognostic value of vitamin D status in dogs with blastomycosis at diagnosis and throughout treatment and remission.

Retrospective analysis of the effects of Blastomyces antigen concentration in urine and radiographic findings on survival in dogs with blastomycosis.

BACKGROUND: The Blastomyces antigen concentration in urine (BACU) test is used to diagnose blastomycosis and monitor treatment in dogs. It is unknown if a higher BACU is associated with shorter survival. OBJECTIVES: To determine if the magnitude of BACU before treatment is associated with survival in dogs with blastomycosis. ANIMALS: Fifty-two dogs with blastomycosis. METHODS: Retrospective case review. BACU, radiographic lung severity (RLS) score (0-4 scale), and survival time up to 1 year after diagnosis were obtained through medical record review of dogs with Blastomyces dermatitidis. RESULTS: The overall survival was: discharge, 87%; 1 week, 85%; 2 months, 74%; and 6 months, 69%. BACU correlated with RLS score (rs = 0.33, P = .02). BACU and RLS scores were lower in survivors to 2 months than nonsurvivors (average BACU difference of 2.5 ng/mL, 95% confidence interval [CI]: 0.2-4.8 ng/mL, P = .04; median RLS difference of 2; range, 0-4, P = .02). Dogs with BACU <5 ng/mL and dogs with mild (0-1) RLS scores had a greater proportion surviving than those with BACU >5 ng/mL (P = .03) and dogs with severe (3-4) RLS scores (P = .04). All dogs with a BACU <5 ng/mL or mild RLS score were alive at last follow-up (median, 365 days; range, 44-365 days). In all, 68.1% of other dogs survived to 2 months (95% CI, 54.8%-84.8%). CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with lower BACU and RLS scores have improved survival; however, it is unclear what specific cutoffs should be used for prognosis.

Upper Airway Obstruction Due to Primary Laryngeal Blastomycosis in a Dog.

A 9 yr old female spayed Labrador retriever presented for progressive dyspnea. Inspiratory stridor and inspiratory and expiratory dyspnea were present, consistent with an upper airway obstruction. A laryngeal exam revealed severe thickening of the arytenoid cartilages and masses associated with the arytenoids. A tracheostomy tube was placed, and the masses were biopsied. Histopathology showed pyogranulomatous inflammation secondary to Blastomyces dermatitidis. The dog was initially treated with amphotericin B and terbinafine in the hospital until the airway obstruction resolved and the tracheostomy tube could be removed. The dog experienced complete recovery after long-term treatment with itraconazole and terbinafine. This is the first report of laryngeal obstruction secondary to primary laryngeal blastomycosis in a dog. Blastomycosis should be considered for cases of obstructive laryngeal disease, and a good outcome can be achieved with antifungal treatment.

Prevalence, distribution, and risk factors for canine blastomycosis in Michigan, USA.

Blastomycosis is a systemic fungal infection that most commonly affects dogs and humans. The disease is thought to be endemic in southern regions of Michigan, USA, but epidemiologic investigations have not been reported in detail for this state. The primary aims of this study were to investigate the prevalence and distribution of canine blastomycosis cases in Michigan and to identify risk factors for infection. Over 200 primary care veterinary clinics throughout the state were surveyed regarding blastomycosis prevalence, and demographic information was obtained from medical records of affected dogs that were evaluated at these clinics. A retrospective case control study was conducted for an additional 49 dogs with blastomycosis that were evaluated at specialty referral centers located in the southern mid-Michigan region. Prevalence rates were calculated for each county, and cases were mapped using geocoding software. Univariable and multivariable analyses were used to identify risk factors for infection. Prevalence rates were ≥100 cases per 100,000 dogs in five counties. Most blastomycosis cases originated from the Upper Peninsula or from a high-density area in the northern Lower Peninsula. Multivariable regression analysis identified travel or residence north of the 45th parallel as a strong risk factor for infection (P < .001). Blastomycosis was uncommon in southern counties. These results refute previous speculations and should be of value to both human and animal health. Given that many heightened risk areas are popular tourist destinations, practitioners across the USA should be mindful of the spatial distribution of blastomycosis in Michigan.

Potential clinical utility of ERC-2 yeast phase lysate antigen for antibody detection in dogs with blastomycosis.

Four Blastomyces antigens ERC-2 (B. gilchristii, dog, Wisconsin), B5929 (human, Minnesota), 597 (human, Wisconsin), and T-27 (polar bear, Tennessee) were tested against 31 serum specimens from dogs with blastomycosis and 19 from healthy dogs. All antigens detected antibody; efficacy varied. ERC-2 showed the highest ELISA mean absorbance value of 3.00 followed by T-27. Test performance varied by sample geographic origin. Further study is needed to determine if ERC-2 antigens may be clinically useful, and whether the combination of the particular fungal species as antigen source, host animal, and the species and geographic location of the patient being tested is important for optimum test characteristics.

25-Hydroxyvitamin D concentrations in dogs with naturally acquired blastomycosis.

BACKGROUND: Hypovitaminosis D is common in humans with tuberculosis, and adequate serum 25-hydroxyvitamin D [25(OH)D] concentrations may improve response to therapy. The pathomechanism of Blastomyces dermatitidis is similar to that of Mycobacterium tuberculosis, but the 25(OH)D status of dogs with blastomycosis has not been investigated. OBJECTIVES: To determine if dogs with blastomycosis have lower 25(OH)D concentrations compared with healthy controls and to explore the prognostic value of 25(OH)D concentrations in blastomycosis. ANIMALS: 35 control dogs (16 client-owned, healthy dogs and 19 healthy, random-source hound mixes) and 22 dogs with blastomycosis. METHODS: Prospective study. Serum concentrations of 25(OH)D, parathyroid hormone (PTH), ionized calcium were measured, and biochemistry and hematology profiles were performed. The 25-hydroxyvitamin D concentrations were compared between groups, and factors associated with 25(OH)D variation were investigated in dogs with blastomycosis. Dogs with blastomycosis were followed for up to 5 years after discharge and factors associated with survival were investigated. RESULTS: Dogs with blastomycosis had significantly lower concentrations of 25(OH)D and PTH and higher concentrations of ionized calcium than did control dogs. In dogs with blastomycosis, 25(OH)D concentrations were independently associated with neutrophil count, pCO2 , and with bone and skin involvement. The 25-hydroxyvitamin D concentration was not associated with survival in dogs with blastomycosis, whereas lactate concentrations; bone, skin, and lymph node involvement; number of affected sites; and, presence of respiratory signs were associated with survival. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with blastomycosis had lower 25(OH)D concentrations than did healthy controls. Despite no impact on survival, investigating the effect of 25(OH)D supplementation on recovery is warranted.

Blastomyces dermatitidis pneumonia in a llama.

A 20-y-old female llama ( Lama glama) was euthanized after a history of chronic dyspnea and osteoarthritis. At autopsy, the lungs were covered by clear gelatinous material and expanded by firm, variably discrete, tan-white nodules up to 8 cm diameter containing tan-white, viscous material. The tracheobronchial lymph nodes were firm and enlarged up to 6 × 4 × 3 cm; the thoracic aorta and carotid arteries were lined by hard, tan-white, mineralized intimal plaques. Histologic examination of lung revealed numerous 10-20 µm diameter yeasts with clear 1-2 µm thick double-contoured walls, central basophilic nuclei, and frequent broad-based budding, consistent with Blastomyces dermatitidis. DNA sequencing confirmed the diagnosis. B. dermatitidis should be considered in the differential diagnosis of pulmonary disease in llamas.

Successful treatment of blastomycosis in a 7-year-old, female golden retriever dog on Manitoulin Island, Ontario.

A 7-year-old female golden retriever dog was presented with a 2-week history of coughing and inappetence. Examination, radiographs, and blood analysis showed classic evidence of blastomycosis, confirmed with the MVista EIA urine antigen test. A 2-month course of itraconazole and a course of mirtazapine, meloxicam, furosemide, and tetracycline resulted in a successful outcome.

Traitement réussi de la blastomycose chez une chienne Golden retriever âgée de 7 ans à l'île Manitoulin, en Ontario. Une chienne Golden retriever âgée de 7 ans a été présentée avec une anamnèse de 2 semaines de toux et d'inappétence. L'examen, les radiographies et l'analyse sanguine indiquaient des preuves classiques de blastomycose, qui a été confirmée par un test de détection d'antigène MVista EIA dans l'urine. Un régime de traitement de 2 mois à l'itraconazole et un traitement à la mirtazapine, au méloxicam, au furosémide et à la tétracycline ont produit des résultats fructueux.(Traduit par Isabelle Vallières).

A retrospective study of anti-inflammatory use in dogs with pulmonary blastomycosis: 139 cases (2002-2012).

OBJECTIVE: To determine the effect of anti-inflammatory medications on 30-day survival of dogs treated for pulmonary blastomycosis. DESIGN: Retrospective study. SETTING: University teaching hospital. ANIMALS: One hundred thirty nine client-owned dogs with confirmed pulmonary blastomycosis. MEASUREMENTS AND MAIN RESULTS: The medical records of dogs diagnosed with pulmonary blastomycosis between May 2002 and October 2012 were identified. Of 139 dogs, 85 (61%) survived to 30 days, 38 (27%) were euthanized due to progressive clinical disease, 13 (10%) died secondary to respiratory or cardiac arrest, and 3 (2%) did not survive to 30 days but had an unknown cause of death. Cases were classified based on the anti-inflammatory therapy that was used: nonsteroidal anti-inflammatory drugs (NSAID), corticosteroids, both, or none. Controlling for the effects of itraconazole dose, sex, age, and pretreatment with anti-inflammatory medication, the odds for survival to 30 days was not statistically different between dogs who received no anti-inflammatory medication and the dogs who received NSAIDs (P = 0.86), corticosteroids (P = 0.65), or both (P = 0.27). The need for supplemental oxygen was associated with decreased survival (P < 0.0001). CONCLUSIONS: In this population of dogs with pulmonary blastomycosis, the use of anti-inflammatory medications during therapy did not impact 30-day survival; however, the need for oxygen supplementation was associated with significantly lower survival.