Constrictive pericarditis secondary to Coccidioides immitis infection in a dog

A 4-year-old castrated male mixed-breed dog with a history of coccidioidomycosis was referred for evaluation of abdominal and pleural effusion. Results of radiography, ultrasonography, cytologic evaluation of thoracic fluid, and serologic testing supported a diagnosis of constrictive pericarditis secondary to infection with Coccidioides immitis. Aggressive treatment for presumptive coccidioidomycosis was begun, but the dog's condition continued to deteriorate, and the dog was euthanatized. At necropsy, the pericardium was thicker than normal and fibrotic and adhered to the epicardium. Microscopically, the pericardium and 1 section of epicardium contained lymphoplasmacytic infiltrates with a few macrophages and neutrophils. Coccidioides immitis was cultured from pericardial fluid. A search of records from the Arizona Veterinary Diagnostic Laboratory for 1988 through 1998 revealed that of 46 dogs in which a diagnosis of coccidioidomycosis was confirmed at necropsy, 13 had involvement of the heart or pericardium.     

Pulmonary coccidioidomycosis in a neonatal foal

A 13-day-old foal with profound tachypnoea and respiratory distress was examined. Thoracic radiographs revealed a severe, diffuse miliary pattern, and the foal was markedly hypoxaemic. It failed to improve with empirical treatment, and was euthanased. Lesions associated with Coccidioides immitis infection were identified at postmortem examination, and were limited to the lower respiratory tract.     

Subtotal pericardectomy and epicardial excision for treatment of coccidioidomycosis-induced effusive-constrictive pericarditis in dogs: 17 cases (1999-2003)

OBJECTIVE: To determine the history, clinicopathologic findings, and results of surgery for effusive-constrictive pericarditis associated with Coccidioides immitis infection in dogs. DESIGN: Retrospective study. ANIMALS: 17 client-owned dogs that underwent a subtotal pericardectomy and epicardial excision. PROCEDURE: Hospital records from May 1999 to June 2003 were reviewed. Data collected included history, clinicopathologic findings, treatments, and outcome. Follow-up information was obtained via recheck examination and by use of standardized telephone interviews with referring veterinarians and owners. RESULTS: All dogs were of large breeds, and most were male (mean age, 4.66 years). Ten dogs had no prior history of C. immitis infection, and 7 dogs had chronic infection with C. immitis. Having a chronic C. immitis infection reduced the odds of survival, compared with no previous infection. All dogs had clinical signs of right-sided heart failure. All dogs had serum titers (range, 1:8 to 1:256) for antibodies against C. immitis prior to surgery, and titers were not significantly associated with outcome. Predominant echocardiographic findings were thickened pericardium, reduced right ventricular filling, and pleural or pericardial effusion. All dogs underwent a subtotal pericardectomy and epicardial excision and had fibrosing pyogranulomatous pericarditis in biopsy specimens obtained during surgery. The perioperative mortality rate was 23.5%, and the 2-year postdischarge survival rate was 82%. CONCLUSIONS AND CLINICAL RELEVANCE: Surgical treatment via subtotal pericardectomy and epicardial excision is successful at relieving right-sided heart failure in dogs with effusive-constrictive pericarditis secondary to C. immitis infection, but long-term treatment with antifungal agents may still be required.     

Coccidioidomycosis in dogs and cats: a review

The dimorphic fungi Coccidioides immitis and Coccidioides posadasii are the causative agents of coccidioidomycosis. Dogs and cats residing in and visiting endemic areas are at risk of exposure to infectious arthrospores. The primary infection is pulmonary and frequently results in chronic cough. Disseminated disease is common and causes cutaneous, osseous, cardiac, ocular, nervous system, or other organ disease. Radiographic changes include a variable degree of interstitial pulmonary infiltration, hilar lymphadenopathy, and osseous lesions. Serological titers support the diagnosis, but definitive diagnosis relies on identification of Coccidioides in cytological or tissue samples. Coccidioidomycosis should be considered in any dog or cat that has been potentially exposed during the previous 3 years and is presented with chronic illness, respiratory signs, lameness, lymphadenopathy, nonhealing cutaneous lesions, or neurological, ocular, or cardiac abnormalities.     

Disseminated coccidioidomycosis in a captive Indochinese tiger (Panthera tigris corbetti) with chronic renal disease.

A 19-yr-old, 78.2-kg captive female Indochinese tiger (Panthera tigris corbetti) from the El Paso Zoo (El Paso, Texas, USA) with chronic renal disease was euthanized after a 10-day course of anorexia, depression, progressive rear limb weakness, muscle fasciculations, and head tremors. Postmortem findings included pericardial effusion, generalized lymphadenopathy, glomerulosclerosis, glomerular atrophy with membranous glomerulonephropathy, and pancreatic adenocarcinoma. Pyogranulomatous pneumonia, pericarditis, and lymphadenitis were associated with fungal spherules histomorphologically consistent with Coccidioides immitis. Rising antibodies to C. immitis were detected on samples obtained perimortem and 2 mo before euthanasia. Retrospective serology was negative for two additional Indochinese tigers, two Iranian leopards (Panthera pardus saxicolor), two jaguars (Panthera onca), two bobcats (Lynx rufus texensis), two ocelots (Leopardus pardalis), and three Amur leopards (Panthera pardus orientalis) housed at the zoo over an 8-yr period. Despite being located within the endemic region for C. immitis, this is only the second case of coccidioidomycosis reported from this institution.     

Comparison of susceptibility of fungal isolates to lufenuron and nikkomycin Z alone or in combination with itraconazole

OBJECTIVE: To evaluate and compare the in vitro antifungal properties of lufenuron and nikkomycin Z against isolates of Coccidioides immitis and Aspergillus fumigatus when used singly and in combination with the azole antifungal agent itraconazole. SAMPLE POPULATION: 3 clinical isolates of A fumigatus and the Silveira strain of C immitis. PROCEDURE: The fungal isolates were tested in vitro for susceptibility to the single and combination of compounds by use of microtiter-format susceptibility methods. Minimum inhibitory concentration end points were determined visually, and the contents of representative wells were examined microscopically for evidence of morphologic effects on fungi. RESULTS: No evidence of inhibition, either by susceptibility testing or direct microscopic examination of treated cells, was obtained with lufenuron under experimental conditions. In contrast, nikkomycin Z, a known inhibitor of fungal chitin synthesis, had potent activity against C immitis when used singly. A synergistic interaction between nikkomycin Z and itraconazole was found against isolates of both species tested. CONCLUSIONS AND CLINICAL RELEVANCE: On the basis of our in vitro data, lufenuron does not appear to possess antifungal properties.     

Isolation of Cokeromyces recurvatus, initially misidentified as Coccidioides immitis, from peritoneal fluid in a cat with jejunal perforation.

Cokeromyces recurvatus, a zygomycete, was isolated by fungal culture from the peritoneal fluid of a cat with jejunal perforation secondary to intestinal lymphosarcoma. This organism has not been recovered previously from a veterinary patient. The tissue form of C. recurvatus is morphologically similar to those of Coccidioides immitis and Paracoccidioides brasiliensis and may be misdiagnosed as 1 of these organisms on the basis of cytologic or histopathologic specimens, particularly in geographic regions where these organisms are not endemic.     

Prevalence of the Dirofilaria immitis infection in dogs from Merida, Yucatan, Mexico

The aim of the present study was to estimate the prevalence of Dirofilaria immitis infection, and to examine the relationship between host factors (gender, age and breed) and D. immitis infection in dogs. The study was designed as a cross-sectional study. A total of 676 dogs were examined for D. immitis infection. Adult worms (necropsy) and blood samples were collected from all animals for diagnosis of D. immitis. Blood samples were examined using a modified Knott's and thick drop techniques. Fifty-six of 676 dogs were diagnosed infected with D. immitis. The odds of infection were 2.85 times higher in female dogs, compared to male dogs (OR = 2.85, 95% CI = 1.5-5.5, P = 0.01). In addition, the odds of infection were 2.11 times higher in > or =3 years old dogs, compared with younger dogs (OR = 2.11, 95% CI = 1.1-4.2, P = 0.03). This information is important for a better understanding of the epidemiology of D. immitis in dogs in Yucatan, Mexico.     

Coccidioidomycosis in llamas in the United States: 19 cases (1981-1989).

Coccidioidomycosis was diagnosed in 19 llamas (California, 9; Arizona, 10). All but 1 had a disseminated form, with pyogranulomas principally in the lungs, thoracic lymph nodes, liver, and kidneys. However, lesions were found in tissue specimens from most organ systems. Antemortem diagnosis was based on radiographic evaluation of the lungs, serologic testing, or presence of spherules of Coccidioides immitis in pyogranuloma aspirates, skin scrapings, or biopsy specimens. Animals residing in endemic areas of southwestern United States are at risk, and llamas appear to be highly susceptible to developing disseminated forms of coccidioidomycosis.     

Coccidioidomycosis in Przewalski's horses (Equus przewalskii).

Coccidioidomycosis is a rare, often subclinical infection in domestic animals caused by the fungus Coccidioides immitis. Because of an apparent high incidence of coccidioidomycosis in Przewalski's horses (Equus przewalskii) housed at a single facility, necropsy records and biomaterials from animals that died between 1984 and 2000 were reviewed (n = 30, 15 males, 15 females). Coccidioidomycosis was the leading cause of death (33%) in this population with lesions in the lungs and tracheobronchial lymph nodes of all animals and variable involvement of the skeletal muscle, heart, kidney, liver, skin, brain, spinal cord, spleen, as well as other regional lymph nodes. At the time of death, affected horses tended to be younger than unaffected animals, were from multiple lineages, and males were over represented. During the same time period, no other exotic equids (n = 76) housed at the same facility were diagnosed with coccidioidomycosis, suggesting that environmental factors are not the sole cause of the high incidence in E. przewalskii. Numbers of the lymphocyte subsets (CD3, CD4, CD5, CD8, CD21+ cells) quantified by flow cytometry were similar between Przewalski's horses and domestic horses (Equus caballus). Although responses of lymphocyte blastogenesis assays were similar between Przewalski's (n = 5) and domestic horses (n = 5) in response to the T cell mitogen concanavalin A, lymphocytes from two of the Przewalski's horses failed to proliferate in response to Coccidioides. One of these horses had systemic disease and the second developed coccidioidomycosis 2 yr later. These results suggest that the immune system of some Przewalski's horses fails to respond appropriately to Coccidioides.     

Pathogenesis and electron microscopic changes of spherulogenesis of Coccidioides immitis (valley fever)

Pathogenesis and electron microscopic changes of spherulogenesis of Coccidioides immitis were determined. The organism showed a strong affinity for lung tissue, with granuloma developing in 100% (n = 40) of animals after subcutaneous and intraperitoneal inoculation. Intranasal instillation of the arthrospores resulted in moderate granuloma, with a markedly low frequency rate of infection in 11 animals (55%). Intradermal inoculation and skin scarification did not induce systemic infection. Unlike other routes used to induce infection, only 30% of the mice showed cutaneous changes, whereas in the group infected by skin scarification, 25% of the animals revealed pathologic changes. Indurated tiny nodular lesions developed in the skin at the site of the inoculation. The lesions did not ulcerate, and complete resolution was observed in 4 to 6 weeks. Electron microscopy of the spherulogenesis showed that the tissue form of the fungus replicated in the host tissues by segmentation of the innermost stratum of the wall of the spherule. The layer appeared to function as a germinating center, and as many as 8 spores of irregular size and shape were produced within a kidney-shaped segment. Many segments were in each spherule. The spores were separated, pushed more centrally, and became rounded to become the endospores. When the endospores were freed, each developed into a spherule.     

Prevalence of Dirofilaria immitis infection in living raccoon dogs assessed by hematological examination

The prevalence of Dirofilaria immitis in free-ranging raccoon dogs (Nyctereutes procyonoides viverrinus) was examined in the southeast region of Kanagawa Prefecture, Japan, using a rapid immunomigration (RIM) test kit. Between April 2007 and March 2010, we examined 108 raccoon dogs rescued and housed by the Kanazawa Zoological Garden. D. immitis infection was found in 8 (7.4%) raccoon dogs. This is the first report to reveal the prevalence of D. immitis infection in living raccoon dogs. The prevalence of the infection was lower than previously reported values obtained on postmortem examination. One reason might be that the present study included young raccoon dogs infected with immature worms. Significant high-risk areas of D. immitis infection in the raccoon dogs were not observed.     

Prevalence of Dirofilaria immitis infection among shelter cats

OBJECTIVE: To determine prevalence of Dirofilaria immitis infection among shelter cats. DESIGN: Cross-sectional study. ANIMALS: 239 cats euthanatized at an animal shelter in southeastern Michigan. PROCEDURE: A gross necropsy focusing on the thoracic cavity, heart, lungs, and pulmonary vessels was performed within 5 hours after cats were euthanatized. Blood was collected directly from the heart of cats found to be infected and tested, using a filter test for microfilariae. Serum was tested for D immitis antigens by use of 2 antigen detection kits and for D immitis-specific antibodies by use of 2 antibody detection kits. RESULTS: Cats ranged from approximately 4 months to 15 years old. Adult D immitis were found in 6 (2.5%) cats. Blood could not be recovered from 1 of the cats with heartworm infection. For the 5 other cats, results of the filter test were negative, and results of both antigen and both antibody tests were positive. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that cats living in an urban area in the northern part of the United States have a low prevalence of adult D immitis infection. However, this is likely to be an underestimate of the true prevalence of infection, because no attempts were made to identify cats infected with larval or juvenile stages of D immitis.     

Prevalence and distribution of Dirofilaria immitis in domestic dogs from Ankara and vicinity in Turkey

A total of 280 dogs in Ankara and vicinity were examined from November 2000 through December 2001 by the PetChek antigen ELISA and polycarbonate filter-acid phosphatase histochemical staining techniques for Dirofilaria immitis infection. Dirofilaria immitis (heartworm) infection was found in 26 dogs (9.3%), all of which were kept always outdoors and non prophylacted by their owners. The distribution of heartworm infected dogs was not uniform. Infection with D. immitis was correlated with differences in age and sex. But, no significant association was found.     

Coccidioidomycosis in horses: 15 cases (1975-1984).

Fifteen confirmed cases of equine coccidioidomycosis that originated in California and Arizona were studied retrospectively. Age, breed, and sex varied among affected horses. The most common historical problems were chronic weight loss (53% of cases) and persistent cough (33% of cases). The most frequent physical examination abnormalities were related to the respiratory tract (60% of cases). In 27% of cases, horses had signs of musculoskeletal pain. Horses consistently had hyperproteinemia, hyperfibrinogenemia, leukocytosis, and neutrophilia. An antemortem etiologic diagnosis was made for 11 (73%) horses, all of which had positive serologic tests for coccidioidomycosis. Of the seropositive horses, 5 (46%) also had positive cultures for Coccidioides immitis. One horse died naturally. The other 14 were euthanatized. Prolonged treatment with specific antifungal agents was attempted in 4 horses without apparent benefit. Postmortem abnormalities included pulmonary parenchymal lesions (64% of cases), thoracic lymphadenopathy (57% of cases), hepatic parenchymal involvement (43% of cases), and osteomyelitis (29% of cases). The lesions were granulomatous or pyogranulomatous and C immitis was observed microscopically in 83% of cases.     

Immunoblot analysis of specific antigen bands predictable for Dirofilaria immitis infection in cats

Serial sera from four mongrel cats experimentally inoculated with infectious larvae of Dirofilaria immitis were analyzed by immunoblot patterns against a phosphate buffered saline-extract of D. immitis. Antigen-specific protein bands detected indicate that the low molecular weight bands of 36, 32, 22, 19 and 14 kDa, are predictable for positive adult worm infection, suggesting diagnostic usefulness for adult D. immitis infection in cats.     

Serologic prevalence of Dirofilaria immitis,Ehrlichia canis,and Borrelia burgdorferi infections in Brazil

Dogs infected with Dirofilaria immitis, Ehrlichia canis, or Borrelia burgdorferi may show nonspecific clinical signs or may be asymptomatic. In Brazil, E. canis and D. immitis infections are frequently diagnosed based on the presence of classical signs; however, serologic tests are seldom performed to confirm the presence of infection. To estimate the seroprevalence of these three canine diseases in Brazil, 2,553 dogs presented at veterinary practices for various tests, routine treatments, or examinations were evaluated by an in-office commercial ELISA test kit (SNAP 3Dx, IDEXX Laboratories). Each dog was examined by the veterinarian, and a whole-blood sample was collected and immediately tested for the simultaneous detection of B. burgdorferi and E. canis antibodies and D. immitis antigen. D. immitis infection was detected in 51 dogs (2.0%) and E. canis antibodies were present in 505 dogs 19.8%). Only one dog tested positive for B. burgdorferi antibodies.     

Dirofilaria immitis and its potential mosquito vectors in central New York State.

Screening of 25,822 dog blood samples indicated approximately a 1% infection rate with Dirofilaria immitis. Dipetalonema reconditum microfilariae were found in approximately 2% of 1,876 feral dogs examined. Laboratory experimentation indicated that 6 of 10 local mosquito species examined allowed successful extrinsic incubation of D immitis. Indices of experimental infection indicated Aedes triseriatus and Anopheles quadrimaculatus were excellent hosts for D immitis, but other factors considered, Aedes vexans probably served as the primary vector of D immitis. Coquillettidia perturbans and Culex pipiens-restuans group were considered unsuitable hosts and thus unlikely vectors of canine heartworm. Natural filarial infections were found in An quadrimaculatus and Ae vexans.     

Prevalence of Dirofilaria immitis infection in dogs from Dandong, China

The aim of the present study was to estimate the prevalence and risk factors of Dirofilaria immitis infection in dogs from Dandong, China. A total of 886 dogs were examined for D. immitis infection by microscopic examination and PCR, indicating that the prevalence was 16.6% (213/886) and 24.0% (147/886), respectively. The odds of infection were significantly higher in older dogs and dogs sheltered in outdoor, compared to the younger ones and ones sheltered in indoor. No significant difference of infection was observed in different genders, and between pure breed and cross-breed dogs in the same rearing conditions. These results indicated that the risk of exposure to D. immitis in dogs is high in Dandong, China, and prophylaxis against the parasite is advisable to decrease the incidence of canine dirofilariosis.     

Is heartworm disease really spreading in Europe?

Based on recently published surveys and newly acquired data, a study was conducted to verify the distribution of filarial worm (Filarioidea) infections in Europe, with particular emphasis on canine heartworm infection (Dirofilaria immitis). A Geographic Information System based on thermal regimen was constructed as a means to identify areas potentially suitable for heartworm transmission, taking into account that the development of D. immitis larvae in the mosquito does not occur below the threshold temperature of approximately 14 degrees C. Furthermore, a bionomic model of D. immitis in its mosquito vectors, which calculates the moving cumulative heartworm development unit parameter, was applied using the available temperature data to assess the theoretic transmission timing of heartworm in Europe. The results show that the earliest infection risk occurs in Spain on March 21 and the latest risk occurs in Spain on September 11. The longest risk period occurs in Spain (Murcia station: March 21-November 11), and the shortest risk period occurs in northeastern Europe. The study also provides the first risk assessment maps for Europe and suggests that if the actual climatic trend continues, filarial infection should spread into previously infection-free areas.