Objective—To determine the organisms most commonly
isolated from pleural fluid from dogs and cats
Animals—51 dogs and 47 cats.
Procedure—Results of bacteriologic culture of pleural
fluid samples obtained by means of thoracentesis
were obtained from medical records. To obtain information
on in vitro antimicrobial susceptibility of organisms
commonly isolated from dogs and cats, records
of all dogs and cats examined during 1998 were
reviewed, and information was obtained on identity
and in vitro antimicrobial susceptibility of aerobic
organisms isolated from samples other than urine or
urinary tract samples.
Results—Median ages of dogs and cats were 4
years. Bacteria were isolated from pleural fluid samples
from 47 of 51 (92%) dogs and 45 of 47 (96%)
cats. Obligate anaerobic bacteria were isolated from
28 dogs and 40 cats. A mixture of obligate anaerobic
and facultative bacteria was isolated from 17 dogs
and 20 cats. Samples from cats most often yielded a
member of the nonenteric group (most commonly
members of the genus Pasteurella), whereas those
from dogs more often yielded a member of the family
Enterobacteriaceae (most commonly E coli).
Conclusion and Clinical Relevance—Results suggest
that antimicrobial agents chosen for the initial
treatment of dogs and cats with pyothorax should be
active against a mixture of obligate anaerobic and facultative
bacteria. (J Am Vet Med Assoc 2000;216:
Objective—To assess the strain heterogeneity of
enrofloxacin-resistant Escherichia coli associated with
urinary tract infections in dogs at a veterinary medical
teaching hospital (VMTH). In addition, strains from
other veterinary hospitals in California were compared
with the VMTH strains to assess the geographic
distribution of specific enrofloxacin-resistant E coli
Sample Population—56 isolates of E coli from urine
samples (43 isolates from dogs at the VMTH, 13 isolates
from dogs from other veterinary clinics in
Procedures—Pulsed field gel electrophoresis was performed
on 56 isolates of E coli from urine samples from
56 dogs. All 56 isolates were tested for susceptibility to
amoxicillin, chloramphenicol, enrofloxacin, tetracycline,
trimethoprim-sulphamethoxazole, cephalexin, and
ampicillin. Enrofloxacin usage data from 1994 to 1998
were obtained from the VMTH pharmacy.
Results—Several strains of enrofloxacin-resistant
E coli were collected from urine samples from the
VMTH, and strains identical to those from the VMTH
were collected from other veterinary clinics in
California. For the isolates that did share similar DNA
banding patterns, variable antibiotic resistance profiles
Conclusions and Clinical Relevance—The
increased occurrence of enrofloxacin-resistant E
coli from urine samples from dogs at the VMTH
was not likely attributable to a single enrofloxacinresistant
clone but may be attributed to a collective
increase in enrofloxacin resistance among uropathogenic
E coli in dogs in general. (J Am Vet Med
Objective—To identify clinical features of Corynebacterium
urealyticum urinary tract infection in dogs and
cats and antimicrobial susceptibility patterns of C urealyticum
Animals—5 dogs and 2 cats.
Procedure—Medical records of dogs and cats for
which C urealyticum was isolated from urine samples
were reviewed. Isolates from clinical cases, along
with previously lyophilized unsubtyped isolates of
Corynebacterium spp collected between 1977 and
1995, were examined and, if subtyped as C urealyticum,
tested for antimicrobial susceptibility.
Results—Signalment of infected animals was variable.
Prior micturition disorders were common, and all
animals had signs of lower urinary tract disease at the
time C urealyticum infection was diagnosed. Median
urine pH was 8.0; WBCs and bacteria were variably
seen in urine sediment. In vitro antimicrobial susceptibility
testing of 14 C urealyticum isolates revealed that
all were susceptible or had intermediate susceptibility
to chloramphenicol, tetracycline, and vancomycin and
most were susceptible to enrofloxacin. Thickening of
the bladder wall and accumulation of sediment were
common ultrasonographic findings. Contrast radiography
or cystoscopy revealed findings consistent with
encrusting cystitis in 3 dogs. Infection resolved in 2
dogs following surgical debridement of bladder
plaques and antimicrobial administration. In 2 other
dogs and 1 cat treated with antimicrobials, infection
with C urealyticum resolved, but urinary tract infection
with a different bacterial species developed.
Conclusions and Clinical Relevance—Results suggest
that preexisting urinary tract disorders are common in
dogs and cats with C urealyticum infection. Treatment
with appropriate antimicrobials in combination with surgical
debridement might eliminate C urealyticum infection.
(J Am Vet Med Assoc 2005;226:1676–1680)
Objective—To determine molecular characteristics, antimicrobial susceptibility, and toxigenicity of Clostridium difficile isolates from horses in an intensive care unit and evaluate associations among severity of clinical disease with specific strains of C difficile.
Procedures—Feces were collected from horses admitted for acute gastrointestinal tract disease with loose feces and submitted for microbial culture and immunoassay for toxin production. Polymerase chain reaction assays were performed on isolates for toxins A and B genes and strain identification.
Results—Isolates were grouped into 3 strains (A, B, and C) on the basis of molecular banding patterns. Toxins A and B gene sequences were detected in 93%, 95%, and 73% of isolates of strains A, B, and C, respectively. Results of fecal immunoassays for toxin A were positive in 40%, 63%, and 16% of horses with strains A, B, and C, respectively. Isolates in strain B were resistant to metronidazole. Horses infected with strain B were 10 times as likely to have been treated with metronidazole prior to the onset of diarrhea as horses infected with other strains. Duration from onset of diarrhea to discharge (among survivors) was longer, systemic inflammatory response syndromes were more pronounced, and mortality rate was higher in horses infected with strain B than those infected with strains A and C combined.
Conclusions and Clinical Relevance—Horses may be infected with a number of heterogeneous isolates of C difficile. Results indicated that toxigenicity and antimicrobial susceptibility of isolates vary and that metronidazole-resistant strains may be associated with severe disease.
Objective—To determine molecular characteristics of
Clostridium difficile isolates from foals with diarrhea
and identify clinical abnormalities in affected foals.
Animals—28 foals with C difficile-associated diarrhea.
Procedure—Toxigenicity, molecular fingerprinting,
and antibiotic susceptibility patterns were determined.
Information on signalment, clinical findings,
results of clinicopathologic testing, whether antimicrobials
had been administered prior to development
of diarrhea, and outcome was obtained from the
Results—Twenty-three (82%) foals survived. Toxin
A and B gene sequences were detected in isolates
from 24 of 27 foals, whereas the toxin B gene alone
was detected in the isolate from 1 foal. Results of
an ELISA for toxin A were positive for fecal samples
from only 8 of 20 (40%) foals. Ten of 23 (43%) isolates
were resistant to metronidazole. Molecular
fingerprinting revealed marked heterogeneity
among isolates, except for the metronidazole-resistant
isolates. Sixteen foals had tachypnea.
Hematologic abnormalities were indicative of
inflammation. Common serum biochemical abnormalities
included metabolic acidosis, hyponatremia,
hypocalcemia, azotemia, hypoproteinemia, hyperglycemia,
and high enzyme activities. Passive transfer
of maternal antibodies was adequate in all 12
Conclusions and Clinical Relevance—Results suggest
that a large percentage of C difficile isolates
from foals with diarrhea will have the toxin A and B
gene sequences. Because of the possibility that isolates
will be resistant to metronidazole, susceptibility
testing is warranted. Clostridium difficile isolates
from foals may have a substantial amount of molecular
heterogeneity. Clinical and hematologic findings in
affected foals are similar to those for foals with diarrhea
caused by other pathogens. (J Am Vet Med
Objective—To evaluate a method of aerobic bacteriologic culture of epidermal collarette specimens from dogs with superficial pyoderma and compare results with those for aerobic bacteriologic culture of abdominal skin specimens in healthy dogs.
Animals—22 dogs with epidermal collarettes and 24 healthy dogs.
Procedure–Dry sterile cotton swabs were rolled across epidermal collarettes or hairless areas of abdominal skin in healthy dogs and submitted for aerobic bacteriologic culture. Hemolytic colonies of gram-positive–staining cocci were tested for catalase production, and if results were positive, a coagulase test was performed. Colonies with coagulase activity were tested for the ability to ferment mannitol. Antimicrobial susceptibility testing was performed on all Staphylococcus spp that were isolated.
Results–S intermedius was isolated from collarettes in 18 of 22 dogs with superficial pyoderma but not from healthy dogs. Estimated sensitivity and specificity of the culture method were 81.8% and 100%, respectively. There were no significant differences in the ability to culture S intermedius, the number of S intermedius isolates without resistance to antimicrobials, and the number of S intermedius isolates resistant to penicillin G when comparing dogs with superficial pyoderma for the first time and dogs with recurrent pyoderma, dogs that did or did not receive concurrent antimicrobials, and dogs with and without underlying allergic disease.
Conclusions and Clinical Relevance–Bacteriologic culture of epidermal collarette specimens was a simple and reliable method for identification of S intermedius in dogs with superficial pyoderma, regardless of history of pyoderma or current antimicrobial use. (J Am Vet Med Assoc 2005;226:904–908)