Counterimmunoelectrophoresis (immunoelectroosmosis) and serum electrophoretic pattern in serologic diagnosis of canine blastomycosis

Counterimmunoelectrophoresis (CIEP) with blastomyces and histoplasma antigens was used in a serologic study of 181 dogs clinically suspected of having blastomycosis and of 8 dogs with confirmed blastomycosis or histoplasmosis. Thirteen of the 181 dogs, positive by CIEP, were euthanatized, and the diagnosis was confirmed by cultivation and/or microscopic detection of Blastomyces dermatitidis. Additional CIEP-positive dogs were confirmed by staining of aspirates collected in vivo. Radiographic support for the diagnosis was reported in 4 other dogs in which histoplasmosis was excluded by a negative CIEP with histoplasma antigen. The precipitating antibody may disappear during the course of the disease, as it did in 1 dog treated with amphotericin B, but not cured. This dog reverted from CIEP-positive to CIEP-negative within 17 months of treatment (with a weak reaction after 10 months of treatment). The CIEP-detectable antibody was present only in 1 dog without a confirmation by histopathologic findings or cultivation among 24 well-documented cases and 181 total tested sera. The CIEP was more sensitive and specific than was the gel-diffusion precipitin test, eliminated the problems of anticomplementarity that often affected the results of complement-fixation tests with canine sera, and served well in detecting dogs with blastomycosis. Electrophoretic pattern of sera from CIEP-positive dogs with blastomycosis showed a decrease in albumin and an increase in alpha 2- and often in beta- and gamma-globulins, with a substantial decrease of the albumin/globulin ratio.     

Treatment of canine blastomycosis with amphotericin B and ketoconazole

The treatment of 62 dogs with blastomycosis was reviewed to identify prognostic factors and response to various treatment regimens. Severity of lung involvement, as determined by radiography, and the number of nonsegmented neutrophils were useful prognostic factors. Females survived treatment better than did males, but females were more prone to relapse. Ketoconazole treatment at a dose of 10 mg/kg daily for 60 days was not as effective as amphotericin B. The most notable adverse effect of amphotericin B treatment was nephrotoxicosis . Treatment with amphotericin B followed by ketoconazole was as effective as amphotericin B alone and resulted in less nephrotoxicosis . Most dogs that had relapses were retreated effectively with amphotericin B and/or ketoconazole. Canine blastomycosis was shown to be a treatable disease, with a cure rate of approximately 75%.     

Calcinosis cutis associated with systemic blastomycosis in three dogs.

Three dogs treated for systemic blastomycosis with intravenous amphotericin B (one case) or amphotericin B lipid complex (two cases) developed mild to severe calcinosis cutis two to six weeks after the initiation of treatment. Abnormalities in serum calcium and phosphorus during treatment for blastomycosis or at the time of diagnosis of calcinosis cutis were slight or absent. The calcification was not associated with lesions of cutaneous blastomycosis. Calcification was limited to the skin in two cases and may have also involved the kidneys in one. The calcinosis cutis resolved completely in all three dogs with no (two cases) or only palliative (one case) therapy.     

Visual outcome in a group of dogs with ocular blastomycosis treated with systemic antifungals and systemic corticosteroids

OBJECTIVE: To evaluate the success of the use of systemic corticosteroids and antifungal medications in the treatment of dogs with ocular lesions associated with systemic blastomycosis. DESIGN: Retrospective study. ANIMALS STUDIED: Medical records of 25 dogs diagnosed with blastomycosis, via either cytology or histopathology, at the Purdue University Veterinary Teaching Hospital between 1 January 2000 and 1 January 2005, were reviewed. PROCEDURE: Data collected from the medical records included signalment, presence and progression of ocular lesions, antifungal drugs administered, oral and topical corticosteroid administration, length of follow-up, response to treatment, and visual outcome. RESULTS: Of the 25 cases reviewed, 12 dogs (19 eyes) with follow-up information were found to have lesions consistent with ocular blastomycosis. Length of follow-up in the 12 cases ranged from 1 month to 31 months with a mean of 9 months. Antifungal therapy for all cases consisted of oral itraconazole (5 mg/kg every 24 h) initially. In seven cases, the antifungal drug administered was changed from itraconazole to oral fluconazole. Two of these also received intravenous amphotericin B, and two received additional treatment with itraconazole. All 12 dogs also received oral prednisone. The dose of oral prednisone utilized ranged from 0.2 mg/kg/day to 1.4 mg/kg/day with a mean of 0.7 mg/kg/day; the duration of oral prednisone administration ranged from 2 weeks to 8.5 months with a mean of 3 months. Topical prednisolone was a component of the treatment of 16 of the 19 eyes. Duration of topical prednisolone treatment ranged from 1 month to 30 months with a mean of 5 months. Lesions not located in the eyes exhibited a positive response to treatment in 11 (92%) of the 12 dogs. Overall, 14/19 (74%) affected eyes were visual at the time of their final recheck. All eyes with mild or moderate lesions and 5/10 (50%) severely affected eyes were visual at their last recorded recheck examination. CONCLUSIONS: The administration of systemic corticosteroids did not appear to adversely affect the survival rate and might have played a role in preservation of vision in a majority of dogs in this group with ocular blastomycosis.     

Canine antibody response to Blastomyces dermatitidis WI-1 antigen

OBJECTIVE: To assess whether dogs with blastomycosis produce antibodies against the WI-1 and A-antigens of Blastomyces dermatitidis and whether the antibodies are useful in serodiagnosis. SAMPLE POPULATION: 359 serum samples obtained from 245 dogs. PROCEDURE: 233 samples from 122 dogs with blastomycosis, and 1 sample each from 24 dogs with suspected blastomycosis, 51 control dogs without infection, and 48 healthy dogs from an enzootic region were obtained. Antibodies against WI-1 antigen were detected by radioimmunoassay (RIA). Serum samples were tested in parallel for antibodies against the A-antigen of B dermatitidis by commercial agar-gel immunodiffusion (AGID) in a reference laboratory. RESULTS: Antibodies were detected in 92% of infected dogs by RIA and in 41 % by AGID. For 29 serum samples that were obtained 11 to 1,545 days after diagnosis, antibodies were detected in 92% of samples by RIA and 7% by AGID. For 93 serial serum samples from 29 dogs with blastomycosis, the mean anti-WI-1 titer was 1:18,761 at the time of diagnosis, and decreased to a mean of 1:1,338 by 210 days after treatment was initiated. Of 24 dogs with suspected infection, antibodies were detected in 67% by RIA and 33% by AGID. Control dogs without blastomycosis had no detectable antibodies in either assay. Thus, sensitivity was 92% for RIA and 41 % for AGID, and specificity was 100% for both tests. CONCLUSIONS AND CLINICAL RELEVANCE: Anti-WI-1 antibodies are readily detected by RIA in dogs with blastomycosis. Titers become high, decline during treatment, and persist for months. Anti-A antibodies are sometimes detected with AGID, but these decrease quickly.     

Treatment of Blastomycosis With Itraconazole in 112 Dogs

One hundred twelve client-owned dogs with blastomycosis were treated with itraconazole, 5 or 10 mg/kg/d. The first group of 70 dogs treated in 1987 and 1988 received 10 mg/kg/d (group 1), and the second group of 42 dogs treated after October 1988 received 5 mg/kg/d (group 2). Even though the groups were treated at different times, the dogs were similar in age and gender distribution, number of sites involved, and percent and severity of pulmonary involvement. The proportion of dogs cured with a 60–day course of itraconazole was similar for both groups (53.6% versus 54.3%) and for a second historical control group treated with amphotericin B (57%); the recurrence rate was also similar, 20%, 21.4%, and 20%, respectively. Dogs treated with itraconazole had similar mortality rates (25.7% at 5 mg/kg/d; 25% at 10 mg/kg/day) to those treated with amphotericin B (23%). Seventeen of the 23 dogs that died (74%), did so during the first week of treatment; these early deaths were usually attributed to respiratory failure. The only site of infection that was significantly associated with failure (death or recurrence) was the brain. There was a marked difference in survival times between dogs without lung disease or with mild lung disease compared with dogs with moderate or severe lung disease. Serum itraconazole concentrations reached steady state by 14 days of treatment. Dogs receiving 5 mg/kg/d of itraconazole (group 2) had mean serum concentrations of 3.55 ± 2.81 mg/mL (range, 0.67 to 10.8 μg/mL), whereas dogs receiving 10 μg/kg/d (group 1) had mean concentrations of 13.46 ± 8.49 μg/mL (range, 1.8 to 28 μg/mL) (P ≤ .001). There was no association between cure and serum itraconazole concentrations. Dogs in group 1 had significantly more adverse effects than dogs in group 2 (P= .046). Anorexia was the most common adverse effect, occurring in 14.9% of dogs in group 1. Only 8% of dogs in group 2 had adverse effects. Serum concentrations of itraconazole were positively correlated with serum alkaline phosphatase and alanine aminotransferase activities. Our findings indicate that itraconazole administered at a dose of 5 mg/kg/d is the drug of choice for blastomycosis in dogs.     

Utility of diagnostic tests for and medical treatment of pulmonary blastomycosis in dogs: 125 cases (1989-2006)

OBJECTIVE: To compare results of the most common diagnostic tests for pulmonary blastomycosis in dogs, identify factors associated with outcome, and determine response to various antifungal treatment protocols. DESIGN: Retrospective case series. ANIMALS: 125 dogs with pulmonary blastomycosis. PROCEDURES: Medical records were reviewed, and information was obtained regarding diagnostic methods, results of routine laboratory testing, and radiographic response to antifungal treatment. RESULTS: 79 dogs survived, 38 died, and 8 were euthanized. Transthoracic fine-needle aspiration and transtracheal lavage were the most common diagnostic methods. Results of an agar gel immunodiffusion test for antibodies against Blastomyces dermatitidis were negative in 12 of 24 (50%) dogs. Only 3 of 94 (3.2%) dogs in which cytologic or histologic examination or bacterial culture of pulmonary samples were performed had any evidence of concurrent bacterial infection. The half-time for radiographic resolution of pulmonary infiltrates did not vary significantly with antifungal treatment, and use of a loading dosage of itraconazole was not associated with significant improvements in outcome or time to disease resolution. Dogs that died had a higher number of band neutrophils at initial examination, compared with those that survived. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the agar gel immunodiffusion test should not be used as the sole diagnostic test for pulmonary blastomycosis in dogs, that concurrent bacterial pneumonia was uncommon in dogs with pulmonary blastomycosis, and that the rate with which pulmonary infiltrates resolved did not vary significantly among antifungal treatments.     

Antigen and antibody testing for the diagnosis of blastomycosis in dogs

BACKGROUND: Early diagnosis and treatment are associated with an improved prognosis in blastomycosis. The diagnosis of blastomycosis may be missed by cytology, histopathology, culture, or serology. An enzyme immunoassay (EIA) for detection of Blastomyces dermatitidis galactomannan antigen in body fluids has been used for rapid diagnosis of blastomycosis in humans. HYPOTHESIS: Measurement of Blastomyces antigen in urine or serum by the MVista Blastomyces antigen EIA is more sensitive than measurement of anti-Blastomyces antibodies for diagnosis of blastomycosis in dogs. METHODS: Serum and urine samples from 46 dogs with confirmed blastomycosis were tested for Blastomyces antigen and serum was tested for anti-Blastomyces antibodies. RESULTS: The sensitivity for the detection of antigen in urine was 93.5% and it was 87.0% in serum. The sensitivity of antibody detection by agar gel immunodiffusion (AGID) was 17.4% and it was 76.1% by EIA. Antigen and antibody decreased during itraconazole treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Antigen detection is a more sensitive test for diagnosis of blastomycosis than antibody testing by AGID, the only commercially available method. Antigen concentrations decreased with treatment.     

Initial and long-term efficacy of a lipid emulsion of amphotericin B desoxycholate in the management of canine leishmaniasis

Sixteen dogs in which canine leishmaniasis (CL) was diagnosed by positive identification of Leishmania amastigotes in bone marrow samples were treated with a mixture of amphotericin B (AmB) desoxycholate in soybean oil. To prevent the toxicity of AmB, dogs were pretreated with saline (50 mL/kg) and mannitol (2 g/kg). Dogs were treated twice weekly with an increasing dosage of amphotericin (0.8-2.5 mg/kg) for between 8 and 10 sessions. Transient adverse effects (anorexia, vomiting, or both) appeared in 81% of the dogs during therapy. At the end of the course, all dogs were clinically cured, with no parasites observed in bone marrow smears. Six of the 16 dogs (38%) were positive by polymerase chain reaction (PCR) in bone marrow samples at some stage of their follow-up, but only 2 were positive at the first test after treatment, which was performed within 5 months after the end of the therapy. The other 4 dogs were initially negative and became PCR-positive at subsequent examinations. Three of these 6 dogs also experienced a clinical relapse. Four dogs had at least 3 consecutive negative PCR tests during a minimum period of 18 months and were clinically cured. The results of the present study indicate that despite having a high initial effectiveness in the treatment of CL, relapses can occur with the described protocol. Also, a single negative PCR result in a recently treated dog cannot be interpreted as a complete cure.     

CT FINDINGS OF INTRACRANIAL BLASTOMYCOSIS IN A DOG

Computed tomography (CT) findings in a dog with intracranial blastomycosis were marked periventricular contrast enhancement of the lateral ventricles, the 3rd ventricle, and the mesencephalic aqueduct. The CT appearance correlated with the histopathologic findings, where severe ependymitis was present throughout the ventricular system and there was stenosis of the mesencephalic aqueduct due to an inflammatory infiltrate. CT is therefore recommended as a screening test for intracranial blastomycosis in dogs and also as an imaging modality for follow-up evaluation after treatment. This is particularly true in dogs with systemic or ocular blastomycosis, which appear to be at higher risk of developing CNS involvement.     

Radiographic findings in dogs with pulmonary blastomycosis: 125 cases (1989-2006)

OBJECTIVE: To identify radiographic patterns in dogs with pulmonary blastomycosis and radiographic factors associated with outcome. DESIGN: Retrospective case series. ANIMALS: 125 dogs with pulmonary blastomycosis. PROCEDURES: Medical records were reviewed, and for each lung lobe, the primary radiographic pattern and percentage of lobar involvement at the time of initial examination were recorded. RESULTS: 79 dogs survived, 38 died, and 8 were euthanized without treatment. The initial radiographic pattern was variable and not significantly associated with outcome. Mean half-time for radiographic resolution of pulmonary infiltrates was 41.4 days for all patterns except masses, for which mean half-time to resolution was 90.8 days. Transient radiographic worsening was seen in 20 of 87 (23%) dogs but was not associated with a poor prognosis. Pulmonary bullae were seen in 20 (16%) dogs, most often in association with an alveolar pattern. Accuracy of using percentage of right caudal lung lobe involvement ( 20%) to predict outcome was 74.4%; accuracy of using number of affected lobes (< 4 vs >or= 4) to predict outcome was 65.8%. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that a nonuniform distribution of pulmonary infiltrates was equally as likely as a diffuse nodular interstitial pattern in dogs with pulmonary blastomycosis. On the basis of half-time for resolution of pulmonary infiltrates, follow-up radiography should be performed no more often than every 4 to 6 weeks in clinically stable patients. Transient radiographic worsening that occurred during the initial weeks of treatment was not associated with a poorer prognosis.     

Cultural and histopathologic confirmation of canine blastomycosis diagnosed by an agar-gel immunodiffusion test

Sixteen sera from 17 dogs with blastomycosis produced a precipitin band identical with the diagnostically significant precipitin A band formed by a Blastomyces dermatitidis reference antiserum and a soluble B dermatitidis yeast-form antigen in the agar-gel immunodiffusion test (94% sensitivity). The other serum from a dog with histopathologic demonstration of B dermatitidis in pulmonic tissues produced an unrelated precipitin band. Sixteen of the 17 diagnoses made by the detection of precipitin A were confirmed by isolation and culture of B dermatitidis or by histopathologic demonstration of the pathogen. Three cases were confirmed by cultural isolation only, 10 by histopathologic demonstration only, and 3 by both. In three other dogs given amphotericin B, there were demonstrable changes in serum precipitin A reactions.     

Long-term outcome of therapy for 59 cats and 11 dogs with cryptococcosis

OBJECTIVE: To determine the outcome of therapy in cats and dogs with naturally occurring cryptococcosis. Design Retrospective study of 59 cats and 11 dogs at the University Veterinary Centre Sydney from 1986 to 2004. METHOD: Following detailed analysis of case notes potential associations between patient characteristics, cryptococcal species, retroviral status (cats), disease severity and type of therapy were examined in relation to duration and success of therapy. Treatment protocols based on amphotericin B, fluconazole and itraconazole were compared. RESULTS: Seventy-six percent of feline patients were successfully treated. For cats, the presence of central nervous system disease was the only factor found to influence outcome. Cats with neurological involvement, disseminated disease or refractory disease treated with amphotericin B containing protocols did as well, on average, as cats with less severe disease treated with azole monotherapy. Amphotericin B was thus an effective agent for treating severe cases of cryptococcosis. The median cumulative dose of amphotericin B for cats cured at the first attempt was 16 mg/kg (range 7 to 23 mg/kg). The median duration of treatment required to effect a cure at first attempt was significantly shorter for fluconazole (4 months; range 1 to 8 months) than for itraconazole (9 months; range 3 to 24 months; P = 0. 0191; Mann Whitney U test). The success rate for treatment of canine cases was 55%. No factor appeared to influence disease outcome in dogs. Large cumulative doses of amphotericin B could be administered via the subcutaneous route in both species and generally with minimal nephrotoxicity. Recrudescence occurred in a significant proportion of animals, in some cases despite a reduction of serum latex cryptococcal antigen agglutination test to zero. CONCLUSION: Although the prognosis of cryptococcosis should be described as guarded, a majority of the canine and especially feline patients can be expected to be cured, although treatment is protracted and expensive.     

Transtracheal aspiration in the diagnosis of pulmonary blastomycosis (17 cases: 2000-2005)

Blastomyces dermatitidis is a common etiologic agent of fungal pneumonia in dogs. Definitive diagnosis is based on cytologic demonstration of the organism in affected tissues. Fluid obtained through transtracheal aspiration has previously been reported to have a low diagnostic yield for B. dermatitidis organisms. This retrospective study identified B. dermatitidis organisms in 76% of samples when transtracheal aspiration was performed in 17 nonsedated dogs with pulmonary blastomycosis. Transtracheal aspiration is a noninvasive and simple procedure that should be considered as an early diagnostic test whenever blastomycosis is a differential diagnosis in dogs with pulmonary disease.     

Evaluation of risk factors for blastomycosis in dogs: 857 cases (1980-1990)

An epidemiologic study was conducted by use of the Veterinary Medical Data Base to investigate risk factors for blastomycosis in dogs. From January 1980 through June 1990, 971 cases of blastomycosis in dogs from 22 North American veterinary teaching hospitals were identified. Of these cases, 114 (11.7%) were excluded from the study because of incomplete information regarding age, body weight, sex, and neuter status. A control group of 417,079 dogs was selected that included all other dogs with medical conditions unrelated to blastomycosis for which records were submitted to the data base during the same period. The prevalence of blastomycosis in dogs was 205/100,000 admissions during the study period. When veterinary teaching hospitals were grouped on the basis of their general geographic location, dogs in the East South central, East North central, West South central, and South Atlantic regions had a significantly (P < 0.05) increased risk of acquiring blastomycosis, compared with that of dogs in the Mountain/Pacific region. When teaching hospitals from all geographic regions were considered, dogs had a significantly (P < 0.05) increased risk of acquiring blastomycosis in autumn, compared with that in spring. Sporting dogs and hounds, as defined by the American Kennel Club, were at increased risk for blastomycosis. At highest risk were Bluetick Coonhounds, Treeing-walker Coonhounds, Pointers, and Weimaraners, compared with mixed-breed dogs. Ages of dogs with blastomycosis tended to be normally distributed. Generally, the highest-risk group was composed of sexually intact male dogs, 2 to 4 years old, weighing 22.7 to 34.1 kg. This same pattern was observed for sporting dogs and hounds.(ABSTRACT TRUNCATED AT 250 WORDS)     

Blastomyces dermatitidis prostatic and testicular infection in eight dogs (1992-2005)

This was a retrospective case study of eight dogs diagnosed with prostatic or testicular B. dermatitidis infection. Signalment, clinical presentation, diagnostic procedures, and treatment options were evaluated. Review of medical records of dogs diagnosed with blastomycosis at the University of Illinois Veterinary Teaching Hospital from 1992 to 2005 yielded four dogs with prostatic blastomycosis (PB) and four dogs with testicular blastomycosis (TB). Three of the four dogs with PB and all four dogs with TB had evidence of urogenital disease. Three dogs with PB had an elevated body temperature and all had systemic disease. All dogs with TB had a normal body temperature, and three had systemic disease and one had clinical signs limited to testicular disease. Cytology or histopathology was used to diagnose PB or TB. Treatment included itraconazole or fluconazole with or without nonsteroidal anti-inflammatory drugs. PB and TB are infrequently recognized and may be under diagnosed due to failure to specifically evaluate these tissues. PB or TB should be considered in the evaluation and staging of male dogs with blastomycosis. Male dogs with urogenital signs should be evaluated via prostatic or testicular cytology or histopathology since proper identification and management of PB or TB may improve overall treatment success.     

Retrospective comparison of the efficacy of fluconazole or itraconazole for the treatment of systemic blastomycosis in dogs

Background: Itraconazole is recommended for treatment of blastomycosis in dogs. Some evidence suggests that fluconazole might be less hepatotoxic than itraconazole. Objectives: To compare (1) incidence of clinical remission and death; (2) treatment duration; (3) total drug cost; (4) incidence of relapse; and (5) incidence of increased ALT activities in dogs with blastomycosis treated with fluconazole or itraconazole. Animals: One hundred and forty‐four dogs with systemic blastomycosis treated with itraconazole or fluconazole from 1998 to 2008. Methods: Retrospective case review. Information obtained included signalment, body weight, clinical signs, drug regimen, treatment duration, time to clinical remission, and laboratory results. Results: Neither treatment efficacy between fluconazole (75% remission) and itraconazole (90% remission) nor relapse rate (18% for itraconazole, 22% for fluconazole) was significantly different (P= .13, .75, respectively). Treatment duration was significantly longer for fluconazole (median 183 days) than for itraconazole (138 days; P= .001). Costs for fluconazole (median $1,223) were significantly less than for itraconazole ($3,717; P < .001). Incidence of increased ALT activities was not significantly different between groups (17% [3/18] for fluconazole, 26% [6/23] for itraconazole; P= .71). Conclusions: Fluconazole is associated with survival to clinical remission in 75% of dogs with blastomycosis. Although dogs receiving fluconazole were treated longer, drug costs were one‐third those of itraconazole. Hepatotoxicosis, as estimated by increases in serum ALT activity, can be observed with similar incidence for both drugs.     

Serum and Urine Blastomyces Antigen Concentrations as Markers of Clinical Remission in Dogs Treated for Systemic Blastomycosis

Background

Serum and urine Blastomyces antigen concentrations can be used to diagnose blastomycosis in dogs.

Objectives

Blastomyces antigen concentrations correlate with clinical remission in dogs during antifungal treatment, and detect disease relapse after treatment discontinuation.

Animals

21 dogs with newly diagnosed blastomycosis monitored until clinical remission (Treatment Phase), and 27 dogs monitored over 1 year from the time of antifungal discontinuation or until clinical relapse (After Treatment Phase).

Methods

Prospective study. Dogs were monitored monthly during treatment and every 3 months after treatment discontinuation, with a complete history, physical exam, chest radiographs, and ocular exam. Urine and serum Blastomyces antigen concentrations were measured at each visit using a quantitative enzyme immunoassay.

Results

At enrollment in the Treatment Phase, Blastomyces antigen was positive in all 21 urine samples (100% sensitivity; 95% CI 85–100%), and in 18 of 20 serum samples (90% sensitivity; 95% CI 70–97%). At 2–4 months of treatment, urine antigen was more sensitive for clinically detectable disease (82%; CI 60–94%) than serum antigen (18%; CI 6–41%). The sensitivity of the urine test for clinical relapse was 71% (CI 36–92%), with close to 100% specificity (CI 84–100%) during after treatment surveillance in this population.

Conclusions

Urine Blastomyces antigen testing has high sensitivity for active disease at the time of diagnosis and during treatment, and moderate sensitivity but high specificity for clinical relapse. Urine testing should be useful at the time of diagnosis, when treatment discontinuation is being considered, and anytime there is poor clinical response or suspicion of relapse.     

Comparison of histologic lesions of endophthalmitis induced by Blastomyces dermatitidis in untreated and treated dogs: 36 cases (1986-2001)

OBJECTIVE: To compare prevalence of organisms and histologic changes in eyes from dogs with blastomycosis that were either untreated or undergoing treatment with itraconazole. DESIGN: Retrospective study. ANIMALS: 36 dogs with endophthalmitis associated with blastomycosis. PROCEDURE: Signalment, results of ophthalmic examination, and duration of treatment with itraconazole were extracted from medical records. Histologic sections from eyes were examined for prevalence and viability (ie, budding) of fungal organisms. A scoring system was devised to assess the degree of inflammation. RESULTS: Clinically, all eyes were blind and had signs of severe endophthalmitis. Histologically, the type and degree of inflammation and prevalence of Blastomyces dermatitidis were not significantly different between dogs treated with itraconazole and untreated dogs or among groups of dogs treated for different time periods (4 to 14, 15 to 28, or 29 to 72 days). Replication of the organisms in vascular tissues as well as avascular spaces in the eyes was similar in treated and untreated dogs. Lens rupture was seen in 12 of 29 (41%) eyes. CONCLUSIONS AND CLINICAL RELEVANCE: Persistence of inflammation in eyes of dogs with naturally occurring blastomycosis is likely attributable to the continued presence of B. dermatitidis, regardless of the duration of treatment with itraconazole. Lens capsule rupture, a common and previously unreported histologic finding, may contribute to cataract formation and continued inflammation.     

Long-term use of cyclosporine in the treatment of canine atopic dermatitis

This retrospective study of 51 dogs with atopic dermatitis (AD) treated with cyclosporine (CsA) for a minimum of 6 months assessed the frequency of dosing and the need for continual treatment to control clinical signs. The study evaluated both medical records and information supplied by the owners in the form of written questionnaires and telephone follow-up. Laboratory parameters, possible adverse effects and owner satisfaction were assessed. The dose of CsA was 5 mg/kg orally per day and dogs received CsA for 6-30 months. At the conclusion of the study period, 28 dogs (55%) needed ongoing CsA to control clinical signs of AD: 8 (15%) received CsA 2-3 days per week, 10 (20%) 4-5 days per week, and 10 (20%) daily. CsA was discontinued in 23 dogs (45%) after 6-24 months due to either a limited response (22%) or after achieving a clinical response (24%). The results suggest that some dogs with AD treated with CsA may not require daily or even ongoing treatment to control clinical signs. Laboratory abnormalities were detected in 13 dogs (25%) during their CsA treatment. Two dogs developed oral growths and three developed hirsuitism. Forty owners (78%) reported no adverse events in their dogs during the treatment period. Thirty-six owners (71%) were satisfied with CsA as treatment for their atopic dog.