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. ( Am J Vet Res 2005;66:1090–1093)
Objective—To quantify inheritance of tricuspid valve
dysplasia (TVD) in a population of Labrador Retrievers
and evaluate the possibility of the effect of a major
locus on TVD.
Animals—521 Labrador Retrievers (345 with known
phenotypes and 176 related dogs with unknown phenotypes).
Procedure—Dogs were considered normal, equivocal,
and affected for TVD on the basis of echocardiographic
appearance of the tricuspid valves.
Information on related dogs was collected for estimation
of heritability of the 3 categories of phenotype,
using a threshold model. Complex segregation analysis
was performed to evaluate the possibility of the
effect of a major locus on TVD.
Results—Heritability of TVD in this population of
dogs was found to be 0.71, a value sufficiently large
to suggest a segregating major locus. Subsequent
complex segregation analysis did not provide sufficiently
strong evidence to indicate influence of a
major locus on the prevalence of TVD. However, complex
segregation analysis for 2 categories of phenotype
(eg, equivocal dogs were grouped with affected
dogs) suggested that there was a single recessive
allele with a substantial impact on the expression of
Conclusion and Clinical Relevance—In Labrador
Retrievers, TVD is a heritable disorder. Affected dogs
and dogs closely related to affected dogs should not
be used for breeding. There was insufficient evidence
to suggest the influence of a major locus on TVD,
although this conclusion was affected by the classification
of dogs for diagnosis of the condition.
(Am J Vet Res 2002;63:816–820)
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 ultrasonographic characteristics of the thyroid gland in healthy small-, medium-, and large-breed dogs and evaluate the relationships of thyroid gland size and volume with body weight and body surface area (BSA).
Animals—72 dogs of small (6 Toy and 6 Miniature Poodles), medium (12 Beagles), and large breeds (12 Akitas and 36 Golden Retrievers).
Procedure—Each dog's thyroid gland was examined ultrasonographically with a 10- to 5-MHz multifrequency linear-array transducer. Size, shape, echogenicity, and homogeneity of thyroid lobes were evaluated on longitudinal and transverse images. Thyroid lobe volume was estimated by use of the equation for an ellipsoid (π/6 [length × height × width]).
Results—Thyroid lobes appeared fusiform or elliptical on longitudinal images and triangular or round to oval on transverse images. In most dogs, thyroid lobes were hyperechoic or isoechoic, compared with surrounding musculature, and had a homogeneous echogenic pattern. Mean length, width, height, and volume of thyroid lobes were significantly greater in Akitas and Golden Retrievers, compared with findings in Beagles or Poodles; mean length, width, and height were significantly greater in Beagles, compared with findings in Poodles. Total thyroid gland volume correlated with body weight (r = 0.73) and BSA (r = 0.74).
Conclusions and Clinical Relevance—Among the dog breeds examined ultrasonographically, thyroid lobe size and volume were more variable than shape, echogenicity, and homogeneity. The correlation of thyroid gland volume with BSA suggests that size of the dog, rather than breed, should be considered when assessing thyroid glands ultrasonographically.
Objective—To characterize a genetic component to
cricopharyngeal dysfunction (CD) in Golden Retrievers.
Procedure—The CD phenotype was determined by
videofluoroscopy, and dogs were classified as affected
if the upper esophageal sphincter (UES) did not open,
if there were morphologic abnormalities of the UES, or
if opening of the UES was delayed for ≥ 6 videofluoroscopic
frames (0.2 seconds) after closure of the
epiglottis. All survey radiographic and videofluoroscopic
studies were reviewed by the same radiologist.
Results—Of the 117 dogs (47 males and 70 females)
with a CD phenotype determined via videofluoroscopy,
21 dogs (18.0%) had abnormalities of the
UES (affected). Of these 21 dogs, 9 were males
(19.1% of all males) and 12 were females (17.1% of all
females). The heritability of CD in a threshold model
was estimated as 0.61, which established that CD
could be passed from parent to offspring. Results of
complex segregation analysis suggested that a single
recessive allele of large effect contributed to the
expression of this disease in Golden Retrievers.
Conclusions and Clinical Relevance—The determination
that CD is inherited in Golden Retrievers is an
important step in providing information for veterinarians
attending dogs with this disorder. Breeders also
require this information to make informed breeding
decisions. ( Am J Vet Res 2004;65:344–349)
Objective—To determine concentrations of 17α-hydroxyprogesterone (17OHP) in serum of healthy bitches during various stages of the reproductive cycle and in bitches with hyperadrenocorticism and to compare the dynamics of 17OHP with those of progesterone.
Design—Prospective evaluation study.
Animals—15 healthy sexually intact bitches and 28 spayed bitches with hyperadrenocorticism.
Procedures—11 healthy bitches were evaluated during estrus, nonpregnant diestrus, and anestrus (group 1); 4 other healthy bitches were evaluated during pregnancy and after ovariohysterectomy (group 2). Cycle stages were determined via physical examination, vaginal cytologic evaluation, and serum progesterone concentration. Bitches with hyperadrenocorticism were evaluated once at the time of diagnosis (group 3). Serum hormone concentrations were determined with immunoassays.
Results—In group 1, the serum 17OHP concentration was significantly higher in diestrus (median, 1.8 ng/mL) than in estrus (median, 1.1 ng/mL) and anestrus (median, 0.2 ng/mL) and higher in estrus than in anestrus. Changes in serum progesterone concentrations accounted for 22% (estrus) or 23% (diestrus) of the variation in serum 17OHP concentrations. In group 2, 17OHP and progesterone concentrations were significantly higher during pregnancy than after ovariohysterectomy. The serum 17OHP concentration in group 3 was significantly lower (median, 0.2 ng/mL) than in group 1 in estrus and diestrus and in group 2 during pregnancy (median, 0.7 ng/mL) but was not different from 17OHP concentrations in anestrus or after ovariohysterectomy (median, 0.2 ng/mL).
Conclusions and Clinical Relevance—Serum 17OHP concentrations in healthy bitches increased during estrus, diestrus, and pregnancy and at those times were higher than in spayed bitches with hyperadrenocorticism.