Objective—To evaluate the effect of carprofen on
hemostatic variables in clinically normal dogs.
Animals—12 clinically normal Labrador Retrievers.
Procedure—10 dogs (6 females, 4 males) received
carprofen (2.2 mg/kg of body weight, PO, q 12 h) for
5 days. Two dogs (untreated control group; 1 female,
1 male) did not receive carprofen. Hemostatic variables
(platelet count, activated partial thromboplastin
time, prothrombin time, fibrinogen, platelet aggregation,
and bleeding time) were assessed for all dogs
prior to treatment, on day 5 of treatment, and 2 and 7
days after discontinuation of the drug (days 7 and 12).
Serum biochemical variables and Hct were assessed
prior to treatment and on days 5 and 12.
Results—In dogs receiving carprofen, platelet aggregation
was significantly decreased, and onset of
aggregation was significantly delayed on days 5, 7,
and 12, compared with pretreatment values.
Activated partial thromboplastin time was significantly
increased on days 5, 7, and 12 over pretreatment
values in treated dogs, but values remained within
reference ranges. Significant differences were not
detected in buccal mucosal bleeding time, other
serum biochemical and hemostatic variables, or Hct,
compared with pretreatment values and the internal
Conclusion and Clinical Relevance—Administration
of carprofen for 5 days causes minor but not
clinically important alterations in hemostatic and
serum biochemical variables in clinically normal
Labrador Retrievers. Carprofen is commonly used to
treat osteoarthritis and chronic pain in dogs, but prior
to this study, its effect on platelet aggregation and
hemostatic variables was unknown. (Am J Vet Res
Objective—To evaluate serum titers obtained by use
of the microscopic agglutination test (ie, MAT titers)
to Leptospira interrogans serovar pomona and autumnalis
and Leptospira kirschneri serovar grippotyphosa
in dogs given a commercial vaccine against serovars
pomona and grippotyphosa.
Animals—Forty 12-week-old puppies and 20 mature
Procedure—Puppies received a commercial vaccine
against serovars pomona and grippotyphosa at 12 weeks
of age, then received a booster vaccine and 3 weeks
later; mature dogs received the vaccine once. Serum
MAT titers to serovars pomona, autumnalis, and grippotyphosa
were measured before vaccination and at 2, 4, 6,
10, and 16 weeks after the first or only vaccination.
Results—Of the 40 puppies vaccinated, 40, 0, and 40
developed MAT titers of > 100 after vaccination to
serovars pomona, grippotyphosa, and autumnalis,
respectively. Microscopic agglutination test titers to
serovar autumnalis were higher than MAT titers to
serovars pomona and grippotyphosa and persisted in
some dogs for 16 weeks (6 weeks longer than for
titers to serovar pomona). Of the 20 mature dogs, 13,
5, and 20 developed MAT titers of > 100 at 2 weeks
to serovars pomona, grippotyphosa, and autumnalis,
respectively. Titers to serovar pomona were higher
and persisted in some dogs beyond 16 weeks after
vaccination, compared with titers to serovars pomona
and grippotyphosa, which persisted for 10 and 6
Conclusions and Clinical Relevance—Subunit vaccines
against serovars pomona and grippotyphosa
induce MAT titers not only to homologous antigens
but also to serovar autumnalis, which could lead to a
misdiagnosis of leptospirosis caused by serovar
autumnalis. (Am J Vet Res 2005;66:1780–1784)
Objective—To determine the gene sequences of
canine and feline cardiac troponin I (cTnI), express the
protein from the cloned gene in vitro, and validate the
use of a commercial cTnI serum analyzer in these
species via detection of the expressed protein or
comparison of sequence homology.
Sample Population—Samples of ventricular
myocardium from 5 healthy adult mixed-breed dogs
and 5 healthy adult domestic shorthair cats.
Procedure—The RNA was extracted from myocardial
samples, and cDNA was synthesized via reverse transcriptase
polymerase chain reaction and sequenced.
The canine cDNA for the coding region was
expressed in cell culture and analyzed by western blot
and sandwich enzyme-linked immunosorbent assays.
Results—Canine and feline cTnI genes were cloned
and sequenced. Homology of the nucleotide and
amino acid sequences of the canine and feline cTnI
genes with human and rodent cTnI genes were high;
the greatest homology was detected between canine
and feline genes (95% and 96%, respectively).
Recombinant canine cTnI protein was detected by a
commercial serum cTnI analyzer and by western blot
Conclusions and Clinical Relevance—Results indicated
that commercial cTnI analyzers can be used to
measure serum cTnI concentration from dogs and
cats. Additionally, our preliminary characterization of
the feline cTnI gene may facilitate further investigation
of cTnI and its role in familial hypertrophic cardiomyopathy
in cats. ( Am J Vet Res 2004;65:53–58)
Objective—To determine the prevalence of biofilm
formation under long-term cell culture conditions in
serum samples of dairy cattle, goats, cats, and dogs,
and to determine whether there is an association
between nanobacteria and biofilm formation.
Sample Population—Serum samples of clinically
normal animals (313 dairy cattle, 48 goats, 140 dogs,
and 44 cats) and animals with various medical conditions
(60 dogs and 116 cats).
Procedure—Serum was incubated under cell culture
conditions and observed for biofilm formation by use
of light microscopy, electron microscopy, and spectroscopy.
A polymerase chain reaction assay was
developed to identify 16S rRNA gene sequences of
Results—Biofilm formation developed in serum samples
of 304 of 313 (97%) cattle, 44 of 48 (92%) goats,
44 of 44 (100%) cats, and 126 of 140 (90%) dogs.
Prevalence of serum samples with positive results for
biofilm formation was not significantly different
between cats or dogs with and without medical conditions
associated with pathologic extraskeletal calcification
processes. Scanning electron microscopy and
spectroscopy of biofilm samples revealed small coccoid
particles consisting mainly of calcium and phosphate.
Polymerase chain reaction assay failed to
amplify sequences of nanobacteria.
Conclusions and Clinical Relevance—Under longterm
cell culture conditions, biofilm made up of aggregates
of calcium and phosphate crystals does form in
serum samples of clinically normal dairy cattle, goats,
cats, and dogs. Disease, however, does not predispose
to biofilm formation in serum samples of dogs
and cats. Our findings did not support the existence
of nanobacteria in serum samples of cattle, goats,
cats, and dogs. (Am J Vet Res 2003;64:176–182)
Objective—To perform respiratory chain enzymatic
activity assays on canine skeletal muscle biopsy specimens
and establish reference range values of skeletal
muscle enzyme activities for dogs.
Sample Population—Biopsy specimens from the
vastus lateralis muscle were obtained from 24 dogs
(8 sexually intact males and 14 sexually intact
females) ranging from 15 months to 6 years of age.
Procedure—Mean values of citrate synthase,
cytochrome-c oxidase, succinate dehydrogenase,
succinate dehydrogenase-cytochrome-c reductase,
nicotinamide adenine dinucleotide (NADH) dehydrogenase,
and NADH dehydrogenase-cytochrome-c
reductase activities were established by use of 6
standard spectrophotometric assays for respiratory
chain enzyme analysis.
Results—Compared with published data for skeletal
muscle enzyme activities in humans, skeletal muscle
enzyme activities in dogs were 2- to 4-fold higher.
Additionally, citrate synthase activity, a marker for
mitochondrial volume, was positively correlated with
age in dogs, suggesting that mitochondrial volume
increases with age, although no apparent change in
respiratory chain enzymatic activity with an increase
in age was found.
Conclusions and Clinical Relevance—Reference
range values for skeletal muscle enzyme activities of
dogs are needed to accurately interpret results of respiratory
chain enzymatic activity assays. During investigation
of metabolic myopathies, if skeletal muscle
biopsy specimens are evaluated for respiratory chain
enzyme kinetics, they should be performed and evaluated
in concert with skeletal muscle biopsy specimens
from clinically normal animals of the same
species. (Am J Vet Res 2004;65:480–484)
Objective—To develop a multiplex polymerase chain
reaction (PCR) assay for the detection of Toxoplasma
gondii and Neospora caninum DNA in canine and
feline biological samples.
Sample Population—Biological samples from 7 cats
with systemic (n = 4) or CNS (3) toxoplasmosis, 6 dogs
with neospora- or toxoplasma-associated encephalitis,
and 11 animals with nonprotozoal disease.
Procedure—Primers for T gondii, N caninum, and the
canine ferritin gene (dogs) or feline histone 3.3 gene
(cats) were combined in a single PCR assay. The DNA
was extracted from paraffin-embedded brain tissue,
CSF, or skeletal muscle. The PCR products with positive
results were cloned, and sequence identity was
Results—Of 7 cats and 4 dogs with immunohistochemical
or serologic evidence of toxoplasmosis, PCR
results were positive for all cats and 3 dogs for T gondii,
and positive for T gondii and N caninum for 1 dog.
Another dog had negative PCR results for both parasites.
Of 2 dogs with immunohistochemical or serologic
evidence of neosporosis, PCR results were positive
for 1 for N caninum and positive for the other for
T gondii. All negative-control samples yielded negative
results for T gondii and N caninum on the PCR assay.
Conclusions and Clinical Relevance—Standard tests
for toxoplasmosis or neosporosis associated with the
CNS rely on serologic, histologic, or immunohistochemical
analysis and can be difficult to interpret. The
multiplex PCR assay with built-in control reactions
could be a complementary clinical tool for the antemortem
diagnosis of toxoplasmosis or neosporosis
associated with the CNS. (Am J Vet Res 2003;64:1507–1513)
Objective—To evaluate prognostic factors, survival,
and treatment protocols for immune-mediated
hemolytic anemia (IMHA) in dogs.
Animals—151 dogs with IMHA not associated with
underlying infectious or neoplastic disease.
Procedure—Information recorded from review of medical
records included signalment at the time of initial
evaluation; vaccination history; 30-, 60-, and 365-day follow-up outcomes; laboratory data; results of imaging
studies; and necropsy findings. Dogs were grouped
according to the presence of spherocytes, autoagglutination,
a regenerative erythrocyte response, and treatments
received (azathioprine, azathioprine plus ultralowdose
aspirin, azathioprine plus mixed–molecular-weight
heparin [mHEP], or azathioprine plus ultralow-dose
aspirin plus mHEP) for comparisons. All dogs received
Results—Cocker Spaniels, Miniature Schnauzers,
neutered dogs, and female dogs were overrepresented.
Alterations in certain clinicopathologic variables were
associated with increased mortality rate. Rates of survival
following treatment with azathioprine, azathioprine
plus ultralow-dose aspirin, azathioprine plus mHEP, and
azathioprine plus ultralow-dose aspirin plus mHEP were
74%, 88%, 23%, and 70%, respectively, at hospital discharge;
57%, 82%, 17%, and 67%, respectively, at 30
days; and 45%, 69%, 17%, and 64%, respectively, at 1
year. In comparison, mean survival rates at discharge
and at 30 days and 1 year after evaluation collated from
7 published reviews of canine IMHA were 57%, 58%,
and 34%, respectively.
Conclusions and Clinical Relevance—Treatment
with a combination of glucocorticoids, azathioprine,
and ultralow-dose aspirin significantly improved short-and
long-term survival in dogs with IMHA. (J Am Vet
Med Assoc 2005;226:1869–1880)
Objective—To evaluate the influence of treatment with ultralow-dose aspirin (ULDAsp) on platelet aggregation, P-selectin (CD62P) expression, and formation of platelet-leukocyte aggregates in clinically normal dogs.
Animals—18 clinically normal dogs.
Procedures—Studies were conducted before and 24 hours after ULDAsp administration (0.5 mg/kg, PO, q 24 h, for 2 days). Whole blood impedance aggregometry for the assessment of platelet function was performed with sodium citrate–anticoagulated blood and aggregation agonists (ADP at 20, 10, and 5 μmol/L; collagen at 10, 5, and 2 μg/mL). Onset, maximum response, and rate of platelet aggregation were recorded. Flow cytometric assays were configured to detect thrombin-induced CD62P expression and platelet-leukocyte aggregates in EDTA-anticoagulated whole blood. Externalized platelet CD62P and constitutive CD61 (GPIIIa) were labeled with antibodies conjugated to phycoerythrin (PE) and fluorescein isothiocyanate (FITC), respectively. Red blood cell–lysed paraformaldehyde-fixed EDTA-anticoagulated whole blood was dual labeled with CD61-FITC and a panleukocyte antibody (CD18-PE) to characterize platelet-leukocyte aggregates.
Results—ULDAsp significantly delayed platelet aggregation onset with ADP at 20 μmol/L by 54% to 104%, attenuated maximum aggregation with various concentrations of ADP and collagen by ≥ 41%, and slowed aggregation rate with the highest ADP and collagen concentrations by ≥ 39%. Depending on the parameter tested, up to 30% of dogs failed to have an ULDAsp effect. Thrombin stimulation significantly increased CD62P expression in platelets and platelet-leukocyte aggregates, but ULDAsp did not alter basal or thrombin-stimulated CD62P expression.
Conclusions and Clinical Relevance—ULDAsp treatment of clinically normal dogs impaired platelet aggregation in most dogs, but did not influence CD62P platelet membrane expression. (Am J Vet Res 2010;71:1294–1304)