Coccidioidomycosis, also known as Valley Fever, is a fungal disease primarily found within the southwestern US, with up to 80% of affected dogs in endemic areas having primary pulmonary infection. 1 , 2 Aside from clinical signs
Coccidioidomycosis is a fungal infection caused by the dimorphic soil-borne fungi Coccidioides immitis and Coccidioides posadasii . Both organisms are found in the soil of high desert climate regions, including the southwestern
Coccidioidomycosis, a systemic fungal infection caused by the dimorphic fungi Coccidioides immitis and Coccidioides posadasii , is a common condition in dogs in Arizona, southern and central California, and other parts of the
Objective—To determine clinical, clinicopathologic,
and radiographic abnormalities in dogs with coccidioidomycosis.
Design—Retrospective case series.
Procedure—Clinical information and results of clinicopathologic
testing were obtained from medical
records. Thoracic radiographs were reviewed to characterize
Results—Dogs ranged from 1 to 10 years old at the
time of diagnosis, with 12 dogs being between 1 and
3 years old. Historical complaints included cough,
lameness, signs of head or neck pain, and difficulty
breathing. Mild anemia, neutrophilia, and monocytosis
were common. All dogs had hypoalbuminemia,
and 8 of 15 had hyperglobulinemia. Thoracic radiographs
of 19 dogs were reviewed. Pulmonary infiltrates
were seen in 13 dogs, with an interstitial pattern
of infiltration being most common. Hilar lymphadenopathy
was seen radiographically in 10 dogs.
Serum from 20 dogs was tested for antibodies
against Coccidioides immitis. One dog was positive
for IgM antibodies, 5 were positive for IgM and IgG
antibodies, and 14 were positive for IgG antibodies.
Quantitative IgG titers measured in 14 dogs ranged
from 1:2 to 1:128 (median and mode, 1:32). In 6 dogs,
histologic examination of biopsy samples revealed
fungal spherules ranging from 8 to 70 μm in diameter.
Conclusions and Clinical Relevance—Results suggest
that in dogs, coccidioidomycosis may be associated
with a wide spectrum of nonspecific respiratory and
musculoskeletal abnormalities. The chronic nature of
the disease makes diagnosis difficult, even in regions in
which the organism is endemic. (J Am Vet Med Assoc
Objective—To determine the history, clinicopathologic
findings, and results of surgery for effusive-constrictive
pericarditis associated with Coccidioides
immitis infection in dogs.
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.
(J Am Vet Med Assoc 2005;227:435–440)
Objective—To determine the seroprevalence of antibodies
against Coccidioides immitis in healthy horses
residing in an area in which the organism is endemic.
Animals—197 healthy horses (in which coccidioidomycosis
had not been previously diagnosed) that
resided in an area of Arizona in which coccidioidomycosis
Procedure—Of the horses evaluated at the Arizona
Equine Medical and Surgical Center during a 6-month
period, 197 with no clinical signs of coccidioidomycosis
were randomly selected for inclusion in the study;
sera were evaluated for IgM and IgG antibodies
against C immitis via an immunodiffusion assay (IgGpositive
samples were assessed quantitatively).
Within 6 months, recheck titer evaluations were
attempted for all seropositive horses.
Results—Serum antibodies against C immitis were
detected in 8 of 197 horses (seroprevalence, 4.06%).
Results of serologic assays were positive for IgG antibodies
and negative for IgM antibodies in 7 horses
and positive for both IgG and IgM antibodies in 1
horse; reciprocal serum IgG antibody titers were low
(none > 8). Follow-up serologic data were obtained
from 5 horses; compared with initial findings, horses
had become seronegative or titers were unchanged
or decreased. Duration of residence in the area was
significantly shorter for seropositive horses than for
Conclusions and Clinical Relevance—Serum antibodies
against C immitis may rarely be detected in healthy
horses residing in an area in which the disease is
endemic; any horse with a detectable serum antibody
titer should be reevaluated after an interval of at least 3
weeks. (J Am Vet Med Assoc 2005;226:1888–1892)
coccidioidomycosis, the assay results indicate seronegativity, whereas subclinically infected dogs have been found to have titers as high as 1:16. 2 Although immunosuppression associated with multicentric neoplasia and successive chemotherapy treatments has the
pyogranulomatous encephalitis and severe chronic focally extensive pyogranulomatous lymphadenitis with intralesional spherules consistent with Coccidioides spp.
Case summary: coccidioidomycosis in a cat.
Coccidioidomycosis is caused by the soil
Objective—To determine the incidence of
Coccidioides infection among dogs residing in a
region in which the organism is endemic (Pima and
Maricopa counties, Arizona) and estimate the rate of
Design—Community-based longitudinal and crosssectional
Animals—124 healthy 4- to 6-month-old seronegative
puppies (longitudinal study) and 381 4- to 18-monthold
dogs with unknown serostatus (cross-sectional
Procedure—Dogs in the longitudinal study were tested
at 6-month intervals for at least 1 year for anticoccidioidal
antibodies. Dogs that became ill were evaluated
for coccidioidomycosis. Dogs in the cross-sectional
study were tested for anticoccidioidal antibodies
once, and clinical abnormalities were recorded.
Results—28 of the 104 (27%) dogs that completed
the longitudinal study developed anticoccidioidal antibodies.
Thirty-two of the 381 (8%) dogs in the crosssectional
study had anticoccidioidal antibodies. Five
seropositive dogs in the longitudinal study and 13
seropositive dogs in the cross-sectional study had
clinical signs of disease. The remaining seropositive
dogs were otherwise healthy and were classified as
subclinically infected. Survival analysis indicated that
the cumulative probability of infection by 2 years of
age was 28%, and the cumulative probability of clinical
infection by 2 years of age was 6%. Titers for clinically
and subclinically infected dogs overlapped.
Conclusions and Clinical Relevance—Results suggested
that young dogs living in the study area had a
high likelihood of becoming infected with Coccidioides
spp, but few developed clinical illness. Serologic testing
alone was insufficient for a diagnosis of clinical disease
because of the overlap in titers between clinically
and subclinically infected dogs. (J Am Vet Med Assoc
medication was recommended.
Coccidioidomycosis is a disease that develops secondary to inhalation of fungal arthroconidia spores and results most commonly in primary pulmonary infections. 1 Most dogs with coccidioidomycosis have no clinical