Objective—To compare the findings of light microscopic
evaluation of routine unstained wet-mounted
preparations and air-dried, modified Wright-stained
preparations of urine sediment with results of quantitative
aerobic bacteriologic culture of urine.
Design—Masked prospective study.
Sample Population—459 urine samples collected by
cystocentesis from 441 dogs.
Procedure—Urinalyses and quantitative bacteriologic
cultures of urine were performed. Unstained wetmounted
preparations and air-dried, modified Wrightstained
urine sediment preparations were examined
by light microscopy for the presence of bacteria.
Results—Compared with results of quantitative bacteriologic
culture, routine unstained preparations and
modified Wright-stained preparations had sensitivities
of 82.4% and 93.2%, specificities of 76.4% and
99.0%, positive predictive values of 40.1% and 94.5%,
negative predictive values of 95.8% and 98.7%, and
test efficiencies of 77.3% and 98.0%, respectively.
Compared with 74 samples that yielded growth on bacteriologic
culture, the routine unstained method had
concordance and misclassification rates of 39.2% and
60.8%, respectively, whereas the Wright-stained
method had concordance and misclassification rates of
78.4% and 21.6%, respectively. Significant associations
between each of occult blood in urine, pyuria,
female sex, and lower urine specific gravity with bacteriuria
detected by Wright-stained sediment examination
and quantitative bacteriologic culture of urine were
Conclusions and Clinical Relevance—Examination of
modified Wright-stained preparations of urine sediment
appeared to be a rapid, cost effective method that significantly
improved the sensitivity, specificity, positive
predictive value, and test efficiency of light microscopic
detection of bacteriuria, compared with that of the routine
unstained method. (J Am Vet Med Assoc 2004;
Objective—To compare accuracy of estimates of cystolith size obtained by means of plain radiography, double-contrast cystography, ultrasonography, and computed tomography.
Sample Population—30 canine cystoliths ranging from 1 to 11 mm in diameter with various mineral compositions.
Procedures—A bladder phantom model was created by filling a rubber balloon with saline (1% NaCl) solution and positioning it on top of a 2% gelatin cushion at the bottom of a water-filled 4-quart container. Cystoliths were individually placed in the bladder phantom and imaged by each of the 4 techniques. For each image, cystolith size was measured by 2 radiologists with computerized calipers, and size estimates were compared with actual cystolith size.
Results—Mean cystolith size estimates obtained by means of radiography, cystography, and computed tomography did not differ significantly from each other. However, for ultrasonographic images, mean ± SD difference between actual and estimated cystolith size (2.95 ± 0.73 mm) was significantly higher than mean difference for radiographic, cystographic, and computed tomographic images. For ultrasonography, mean ± SD percentage overestimation in cystolith size was 68.4 ± 51.5%.
Conclusions and Clinical Relevance—Results indicated that measurements of cystolith size obtained by means of ultrasonography may overestimate the true size. This suggests that cystolith size estimates obtained by means of ultrasonography should be interpreted with caution whenever cystolith size may influence patient management.
Procedures—Cats were randomly assigned to be fed 1 of 2 low-magnesium, urine-acidifying dry foods (food A or B). For each cat, physical examination, urinalysis, and abdominal radiography were performed weekly to assess treatment response.
Results—32 cats had complete urolith dissolution. Mean ± SD times for a 50% reduction in urolith size (0.69 ± 0.1 weeks) and complete urolith dissolution (13.0 ± 2.6 days) were significantly shorter for cats fed food A, compared with those (1.75 ± 0.27 weeks and 27.0 ± 2.6 days, respectively) for cats fed food B. At study termination, mean ± SD urine pH (6.083 ± 0.105) for cats fed food A was lower than that (6.431 ± 0.109) for cats fed food B. In 5 cats, uroliths did not dissolve and were subsequently determined to be composed of 100% ammonium urate (n = 4) or 100% calcium oxalate (1). Adverse events associated with diet were not observed in any of the cats.
Conclusions and Clinical Relevance—Results indicated that dietary dissolution is safe and effective for eradication of sterile struvite uroliths in cats. Cats fed food A had faster urolith dissolution than did cats fed food B. Lack of a reduction in urolith size at 2 weeks after diet initiation was indicative of misdiagnosis or noncompliance.
Objective—To assess antimicrobial resistance among bacteria isolated from dogs and cats admitted to a veterinary teaching hospital (VTH), determine the incidence of acquisition of and frequency of persistent colonization by antimicrobial-resistant organisms among these animals, and identify risk factors associated with these variables.
Design—Prospective longitudinal study.
Animals—622 dogs and 92 cats admitted to a VTH and expected to stay ≥ 48 hours.
Procedures—Samples were collected with rectal and nasal or oropharyngeal swabs at admission and discharge. Isolates of enterococci, staphylococci, and Escherichia coli were tested for antimicrobial resistance via microbroth dilution methods. A subset of isolates was analyzed with pulsed-field gel electrophoresis and multilocus sequence typing. Significant trends in proportions of organisms with antimicrobial resistance over the 3-year study period were assessed.
Results—The proportion of staphylococci with antimicrobial resistance increased, whereas the proportion of E coli with resistance decreased, over time; resistance among enterococci was more variable. For 506 dogs with paired admission and discharge samples, multidrug-resistant (MDR) E coli was acquired by 40 (8%) and methicillin-resistant Staphylococcus aureus (MRSA) was acquired by 7 (1.4%); hospitalization for > 3 days was significantly associated with both variables. Most (5/7 isolates) acquired MRSA was of sequence type (ST) 5.
Conclusions and Clinical Relevance—Extended hospitalization was associated with increased risk of acquiring MDR E coli or MRSA, although few animals acquired MRSA. It is unclear whether associations were confounded by illness severity or use of infection control measures. Additionally, MRSA of ST5, which has been associated with small animal medicine, was the most commonly acquired MRSA in this study.
Objective—To determine whether short-term amitriptyline
administration would be efficacious in the treatment
of acute, nonobstructive, idiopathic lower urinary tract
disease in cats.
Design—Randomized controlled trial.
Animals—31 untreated male and female cats with acute,
nonobstructive, idiopathic lower urinary tract disease.
Procedures—Cats were treated with amitriptyline (5
mg/d; n = 16) or a placebo (15) for 7 days and monitored
for pollakiuria, hematuria, and adverse events.
Cats were reexamined 1 month after treatment, and
owners were interviewed by telephone 6, 12, and 24
months after treatment.
Results—2 amitriptyline-treated cats were excluded
from analyses because of acquired urinary tract infection.
Clinical signs resolved by day 8 in 8 amitriptylinetreated
and 10 control cats. There were no apparent differences
in likelihood or rate of recovery from pollakiuria
or hematuria between groups. Overall, clinical signs
recurred significantly faster and more frequently in
amitriptyline-treated than control cats. However, after
excluding recurrences within 21 days of treatment, risk
of recurrence was similar in both groups. Increasing age
was significantly associated with increased likelihood
and rate of recovery from hematuria and with decreased
risk of recurrence of signs.
Conclusions and Clinical Relevance—Results suggest
that short-term amitriptyline treatment has no
benefit in terms of resolution of pollakiuria and hematuria
in cats with idiopathic lower urinary tract disease
and may be associated with an increased risk of
recurrence. (J Am Vet Med Assoc 2003:222:749–758)
Objective—To determine the prevalence of antibodies against 6 Leptospira serovars and determine risk factors associated with positive Leptospira titers in healthy client-owned dogs in Michigan.
Animals—1,241 healthy dogs at least 4 months of age.
Procedures—Dogs were examined by veterinarians at private practices. Vaccinated and unvaccinated dogs were enrolled in the study, which occurred prior to the availability of a 4-serovar (Canicola, Grippotyphosa, Icterohaemorrhagiae, and Pomona) Leptospira vaccine. Sera were tested by use of the microscopic agglutination test to determine antibody titers against Leptospira serovars Bratislava, Canicola, Grippotyphosa, Hardjo, Icterohaemorrhagiae, and Pomona. A questionnaire was used to collect demographic information about each dog to identify risk factors associated with seropositive status.
Results—309 of 1,241 (24.9%) dogs had antibody titers against at least 1 of the 6 Leptospira serovars, which suggested exposure to Leptospira spp. Prevalence of antibodies was highest to serovar Grippotyphosa, followed by Bratislava, Canicola, Icterohaemorrhagiae, and Pomona. Age, travel outside Michigan, exercise outside fenced yards, and exposure to livestock and wildlife were significant risk factors for positive titers.
Conclusions and Clinical Relevance—Among healthy dogs from the lower peninsula of Michigan, > 20% have antibodies against leptospiral serovars historically considered uncommon but more recently incriminated as causing clinical canine leptospirosis. Wildlife and livestock may be of increasing importance as reservoirs for canine leptospirosis as urbanization continues to occur. Expanded vaccination strategies may partially mitigate these trends.
Animals—31 cats with acute nonobstructive idiopathic cystitis.
Procedures—Cats were assigned to receive 1 of 2 foods (a cystitis prevention or control food) that differed in mineral (calcium, phosphorous, and magnesium), antioxidant, and fatty acid profiles. Owners documented LUT signs daily for up to 1 year. The primary endpoint was the number of recurrent episodes in which a cat had multiple (≥ 2 concurrent) LUT signs within a day (defined as multiple-sign day). Consecutive days in which a cat had multiple LUT signs were considered as a single episode.
Results—4 cats fed prevention food and 2 cats fed control food were excluded from analysis because of noncompliance, gastrointestinal signs, food refusal, or owner voluntary withdrawal. The proportion of cats fed prevention food that had ≥ 1 recurrent episode of multiple-sign days (4/11) was not significantly lower than that of cats fed control food (9/14). However, cats fed prevention food had significantly lower mean incidence rates for recurrent episodes of multiple-sign days (0.7 episodes/1,000 cat-days) and episodes of hematuria (0.3 episodes/1,000 cat-days), dysuria (0.2 episodes/1,000 cat-days), and stranguria (0.2 episodes/1,000 cat-days) as single LUT signs, compared with cats fed control food (5.4, 3.4, 3.1, and 3.8 episodes/1,000 cat-days, respectively). Significantly fewer cats fed prevention food required analgesics (4/11), compared with cats fed control food (12/14).
Conclusions and Clinical Relevance—Foods with differing nutritional profiles appeared to impact mean incidence rates of recurrent feline idiopathic cystitis-associated signs.
Objective—To determine whether pamidronate disodium
can reduce cholecalciferol-induced toxicosis
in a dose-related manner.
Animals—20 clinically normal, 8- to 12-month-old
Procedure—All dogs were given 8 mg of cholecalciferol
(CCF)/kg of body weight once orally, then were randomly
assigned to 4 groups of 5 dogs each. Dogs were treated
with IV administration of 0.9% NaCl solution (SC
group), 0.65 mg of pamidronate/kg in 0.9% NaCl solution
(LP group), 1.3 mg of pamidronate/kg in
0.9% NaCl solution (MP group), or 2.0 mg of
pamidronate/kg in 0.9% NaCl solution (HP group) on
days 1 and 4 after administration of CCF. Dogs were
observed for 14 days, and serial blood samples were collected
for serum biochemical, electrolyte, and 25-hydroxyvitamin
D3 analyses. Urine samples were collected for
determination of specific gravity. Glomerular filtration rate
(GFR) was determined by plasma iohexol clearance.
Histologic examination of renal tissue was performed.
Results—One dog in the SC group was euthanatized 3
days after administration of CCF because of severe clinical
signs of toxicosis. Dogs in the HP group had significantly
higher mean GFR (day 3), serum potassium concentrations
(day 14), and urine specific gravity (days 7
and 14) and significantly lower mean serum creatinine
concentrations and total calcium × phosphorus concentration
product (days 4 and 7) than dogs in the SC
group. Dogs in the HP group had no abnormal findings
on histologic examination of renal tissue, dogs in the LP
and MP groups had trace to mild mineralization of renal
tissue, and dogs in the SC group had moderate mineralization
and cellular necrosis of proximal renal tubules.
Conclusions and Clinical Relevance—Pamidronate
disodium is a potentially useful drug to reduce CCFinduced
toxicosis and other causes of hypercalcemia
associated with increased bone resorption in dogs.
(Am J Vet Res 2000;61:9–13)
Objective—To evaluate the effects of nephrotomy on
renal function in clinically normal cats.
Animals—20 specific-pathogen-free, 9- to 11-month old
female mixed-breed cats.
Procedure—Serum chemistry analyses, CBC determinations,
urinalyses, microbiologic urine cultures,
renal ultrasonography, abdominal radiography, and
single-kidney and total glomerular filtration rate (GFR)
determinations by use of renal scintigraphy and measurements
of plasma disappearance of technetium
99m-diethylenetriaminepentaacetic acid were performed
before surgery and at 3, 12, 26, 52, and 78
weeks after surgery in 10 cats that underwent unilateral
nephrotomy and in 10 control cats that underwent
a sham surgical procedure.
Results—Two cats (1 from each group) did not complete
the study, and their data were eliminated from
analyses. Unilateral nephrotomy resulted in a 10% to
20% reduction in mean single-kidney GFR, compared
with that of nephrotomy contralateral control kidneys.
However, mean total GFR in nephrotomy-group cats
was not significantly different from that of shamgroup
cats. Over the 78 weeks of study, mean total
GFR declined 34% and 40% in nephrotomy- and
sham-group cats, respectively. Adverse events associated
with nephrotomy included persistent microscopic
hematuria, renal pelvis hyperechogenicity with
distant shadowing on ultrasonographic evaluation,
dilatation of renal pelves, and hydronephrosis.
Conclusions and Clinical Relevance—Nephrotomy
in normal functioning feline kidneys results in a modest
relative reduction in renal function, compared with
contralateral kidney controls, but has minimal effect
on total GFR when compared with sham-operated
control cats. However, any detrimental effects of
nephrotomy may be magnified in cats with diseased
kidneys, which may have little or no capacity for repair
or compensation. (Am J Vet Res 2005;66:1400–1407)