Objective—To characterize serologic and clinical features
and outcome of dogs with leptospirosis that
were treated conservatively (ie, medical management
alone) or with hemodialysis.
Animals—36 dogs with leptospirosis.
Procedure—History; results of physical examinations,
ultrasonography, and serologic, hematologic,
and serum biochemical analyses; time to resolution of
azotemia; and outcome were obtained from medical
records. Dogs were treated conservatively (n = 22) or
with hemodialysis (14).
Results—Between 1990 and 1998, amount of rainfall
was positively correlated with number of cases of leptospirosis
identified per year. Serum antibodies
against 6 Leptospira serovars were measured, and
titers were highest to Leptospira pomonain 16 (44%)
dogs, L bratislava in 9 (25%) dogs, and L hardjo in 1
(3%) dog. Eight (22%) dogs had equally high titers to
L pomona and L bratislava, 1 (3%) had equally high
titers to L grippotyphosa and L canicola, and 1 (3%)
had high titers to L grippotyphosa, L pomona, L canicola,
and L bratislava. During initial evaluation, all dogs
were azotemic. Thirty (83%) dogs survived, including
12 of 14 (86%) dogs treated with hemodialysis and 18
of 22 (82%) treated conservatively. Serum creatinine
concentration was similar in both groups after resolution
of clinical signs.
Conclusion and Clinical Relevance—Infection with
L pomona and L bratislava was recognized as a cause
of leptospirosis in dogs, and resulted in development
of acute renal failure with various degrees of
azotemia. Prognosis for dogs with mild to moderate
azotemia was good with conservative treatment,
whereas treatment with hemodialysis appeared to
improve prognosis for dogs with severe azotemia. (J
Am Vet Med Assoc 2000;216:371–375)
OBJECTIVE To compare dialysate sodium concentration and patient plasma sodium concentration of dogs during intermittent hemodialysis treatments.
SAMPLE 211 intermittent hemodialysis treatments performed on 40 client-owned dogs for the management of dialysis-dependent uremia.
PROCEDURES Medical records were reviewed to determine the plasma sodium concentration of each dog before and after routine hemodialysis treatments. Associations between detected changes in plasma sodium concentration and dialysate sodium concentration were evaluated by use of Spearman rank correlations and linear regression analysis.
RESULTS Significant linear correlations were found between the dialysate sodium concentration and patient sodium concentration. The starting dialysate-to-patient sodium gradient was associated with the strongest correlation to the change in patient sodium concentration at the end of the dialysis session. Modest correlations existed between the dialysate sodium concentration and postdialysis patient sodium concentration as well as between the predialysis dialysate-to-patient sodium gradient and postdialysis dialysate-to-patient sodium gradient.
CONCLUSIONS AND CLINICAL RELEVANCE The dialysate sodium concentration was correlated with the patient sodium concentration in dogs, and the dialysate-to-patient sodium gradient could be used to further refine this association to predict the postdialysis patient sodium concentration and potentially manage dysnatremia during hemodialysis. Prospective studies should be performed to determine how these associations can be used to correct aberrations as well as to avoid unwanted alterations in patient sodium concentrations.
Objective—To evaluate quantification of the amount
of carbamylated hemoglobin (CarbHb), using capillary
electrophoresis (CE) and a new dynamic capillary
coating system to separate hemoglobin derivatives,
and to assess the use of CarbHb amounts to evaluate
long-term urea exposure and differential diagnoses of
azotemia in dogs.
Animals—8 dogs with renal failure, 2 dogs with diabetes
mellitus, and 7 control dogs.
Procedure—Optimal analytic conditions for separation
of CarbHb and other hemoglobin derivatives in
blood samples obtained from dogs were determined,
using a commercial analysis system developed for
the detection of glycohemoglobin Hb A1c (GlycHb) in
human blood samples. Relative content of hemoglobin
derivatives in blood from 10 dogs with renal failure
or endocrine diseases were compared with values for
7 dogs without renal or endocrine diseases.
Results—Satisfactory resolution of hemoglobin derivatives
was obtained, which permitted identification
and quantitation of the amount of CarbHb as a percentage
of the total amount of hemoglobin. Normal or
increased amounts of GlycHb did not interfere with
CarbHb analysis. Dogs with chronic renal failure had
considerably higher peak amounts of CarbHb than
dogs with acute renal failure, a dog with chronic renal
failure that was treated by use of hemodialysis, or
dogs without renal disease.
Conclusions and Clinical Relevance—Amounts of
CarbHb in blood samples obtained from dogs can be
readily quantified by use of capillary electrophoresis.
Assessment of the amount of CarbHb can be used to
facilitate evaluation of the cause of azotemia in dogs.
(Am J Vet Res 2001;62:1302–1306)
Objective—To compare plasma clearance of inulin and iohexol determined by use of 9 plasma samples for evaluation of glomerular filtration rate in dogs and to evaluate limited-sample approaches for evaluation of plasma clearance of these markers.
Animals—43 dogs of various breeds that weighed between 5.5 and 63 kg and that had various degrees of renal function.
Procedures—9 plasma samples were obtained from each dog at 5 minutes to 6 hours after IV bolus injection of iohexol and inulin. Clearance was calculated by use of results for all 9 samples (ie, reference method). Results for 3 limited-sample strategies for determination of plasma clearance of iohexol and inulin were compared with results for the reference method.
Results—Mean clearance of inulin and iohexol for the reference method was 2.72 and 2.48 mL/min/kg, respectively. The mean difference between clearance of these 2 markers for the reference method was 0.24 mL/min/kg. In general, use of the limited-sample strategies yielded clearance values similar to those for the reference method. More accurate estimates of clearance were obtained for iohexol than for inulin by use of the limited-sample methods.
Conclusions and Clinical Relevance—Use of iohexol and inulin yielded similar but not identical results for plasma clearance. Accuracy for limited-sample methods would be acceptable for many clinical and research situations. (Am J Vet Res 2010;71:1100–1107)
Objective—To evaluate the use of multifrequency
bioelectrical impedance analysis (MF-BIA) for estimating
total body water (TBW), extracellular fluid
volume (ECFV), and intracellular fluid volume (ICFV)
Animals—9 healthy mares.
Procedure—TBW and ECFV were measured by use
of deuterium oxide and sodium bromide dilution techniques,
respectively. Intracellular fluid volume was
calculated as the difference between TBW and ECFV.
Concurrently, MF-BIA recordings were obtained by
use of 4 anatomic electrode positions and 3 measurements
of length. Models for MF-BIA data were
created for all combinations of length and anatomic
electrode position. Models were evaluated to determine
the position-length configuration that provided
the most consistent estimates of TBW, ECFV, and
ICFV, compared with values determined by use of the
Results—Positioning electrodes over the ipsilateral
carpus and tarsus and use of height at the tuber
sacrale for length provided the closest estimate
between values for TBW, ECFV, and ICFV predicted by
use of MF-BIA and measured values obtained by dilutional
techniques. This model had the narrowest 95%
limits of agreement.
Conclusions and Clinical Relevance—MF-BIA
techniques have been used to predict changes in
TBW, ECFV, and ICFV in healthy and diseased
humans. Results reported in this study provide an
equine-specific model to serve as the basis for further
evaluation of MF-BIA in horses with altered fluid
states. The MF-BIA techniques have a number of
potential applications for use in horses, including
evaluation of exercise physiology, pharmacologic
studies, and critical-care management. ( Am J Vet Res 2004;65:320–326)
Objective—To characterize the effect of maintenance
hemodialysis on plasma amino acid concentrations
and to quantitate free amino acid losses into the
dialysate during hemodialysis in healthy dogs.
Animals—8 healthy adult dogs.
Procedure—Five dogs received hemodialysis treatments
3 times per week for 4 weeks. Plasma amino
acid concentrations were evaluated once per week
for 4 weeks in each of the 5 dogs prior to hemodialysis
(time 0), 90 minutes during hemodialysis, and
immediately after hemodialysis (180 minutes). Total
free amino acid concentrations and plasma amino
acid concentrations (time 0, 90 minutes, and 180 minutes)
in the dialysate were evaluated in 3 dogs that
received 1 hemodialysis treatment.
Results—Significant time versus week interactions
with any plasma amino acid were not detected; however,
significant decreases in all plasma amino acid
concentrations measured were detected at the midpoint
of dialysis (46 ± 2%) and at the end of each dialysis
session (38 ± 2%). Mean (± SEM) total free
amino acid loss into the dialysate was 2.7 ± 0.2 g or
0.12 g/kg of body weight.
Conclusions and Clinical Relevance—Hemodialysis
is associated with significant alterations in plasma
amino acid concentrations and loss of free amino
acids into the dialysate. Loss of amino acids into the
dialysate, coupled with protein calorie malnutrition in
uremic patients, may contribute to depletion of amino
acid stores.(Am J Vet Res 2000;61:869–873)
Objectives—To determine effects of commonly used diuretic treatments on glomerular filtration rate (GFR), renal blood flow (RBF), and urine output (UO) and compare 2 methods of GFR measurement in healthy awake cats.
Animals—8 healthy cats.
Procedure—In a randomized crossover design, cats were randomly allocated to 4 groups: control; IV administration of fluids; IV administration of fluids and mannitol; and IV administration of fluids, dopamine, and furosemide. Inulin and para-aminohippuric acid were used for determination of plasma clearance for GFR and RBF, respectively. Plasma clearance of technetium-Tc-99m-diethylenetriaminepentacetic acid (99mTc-DTPA) was also used for GFR determination.
Results—Furosemide-dopamine induced the largest UO, compared with other groups. Both mannitol and fluid therapy increased RBF, compared with the control group. Mannitol, and not fluid therapy, increased RBF, compared with furosemide-dopamine. There were significant differences in GFR values calculated from 99mTc-DTPA and inulin clearances between the 2 groups. In all groups, use of 99mTc-DTPA caused underestimation of GFR, compared with use of inulin.
Conclusions and Clinical Relevance—In healthy awake cats, administration of furosemide-dopamine did not increase GFR or RBF despite increased UO. Fluid therapy and fluid therapy plus mannitol improved RBF. Determination of GFR by use of 99mTc-DTPA cannot always be substituted for inulin clearance when accurate measurement is required.
To determine whether ultrasonographic features in dogs with protein-losing nephropathy (PLN) were associated with renal biopsy findings and compare corticomedullary ratios between dogs with PLN versus non-renal disease.
71 dogs with PLN and 33 dogs without renal disease.
Medical records and archived ultrasonographic images for dogs with PLN that underwent renal biopsy between 2008 and 2018 were reviewed. Corticomedullary ratios were measured.
In dogs with PLN, median serum creatinine and BUN concentrations and urine-protein-to-creatinine-ratio prior to renal biopsy were 3.4 mg/dL (interquartile range [IQR], 1.2 to 5.3 mg/dL), 80 mg/dL (IQR, 28 to 105 mg/dL), and 11.4 (IQR, 6.4 to 18.3), respectively. Histologic abnormalities within the tubulointerstitial space were associated with cortical echogenicity. Gastric wall thickness > 5 mm was associated with a histologic diagnosis of acute glomerular disease. Dogs with immune complex–mediated glomerular disease were more likely to have abnormal gastric mural architecture. Other ultrasonographic features of the kidneys, liver, and stomach and the presence of ascites did not help to differentiate immune complex–mediated from non-immune complex–mediated glomerular disease, acute from chronic disease, or amyloid from non-amyloid disease or distinguish whether tubulointerstitial disease was present or absent. Median left corticomedullary ratio for 66 dogs with PLN (1.2) was significantly higher than that for the 33 dogs without renal disease (1.0).
Ultrasonographic features were poorly associated with specific pathological disorders in dogs with PLN. In this study, the corticomedullary ratio was higher in dogs with PLN, indicating the presence of cortical thickening, but the clinical relevance is unknown.
Objective—To determine sensitivity and specificity of
radiography, ultrasonography, and antegrade pyelography
for detection of ureteral obstructions in cats.
Procedure—Medical records of cats that had radiography,
ultrasonography, and antegrade pyelography
performed for suspected ureteral obstructions were
examined. Ultrasound-guided pyelocentesis and fluoroscopic-
assisted antegrade pyelography were performed
on 18 kidneys in 11 cats. Obstructive ureteral
lesions were confirmed in all cats by surgical or
necropsy examination. Sensitivity and specificity of
survey radiography, ultrasonography, and antegrade
pyelography for identification of ureteral obstructions
were calculated. Surgical or necropsy findings were
used as the standard for comparison.
Results—All cats were azotemic. Mean ± SD serum
creatinine and BUN concentrations were 10.2 ± 6.1
and 149 ± 82 mg/dL, respectively. Fifteen of 18
ureters were found to be obstructed at surgery or
necropsy. Sensitivity and specificity were 60 and
100% for radiography and 100 and 33% for ultrasonography,
respectively, in identification of ureteral
obstructions. Leakage of contrast material developed
in 8 of 18 kidneys during antegrade pyelography and
prevented diagnostic interpretation in 5 of 18 studies.
For the 13 diagnostic studies, specificity and sensitivity
were 100% by use of the antegrade pyelography
technique. Correct identification of the anatomic location
of the ureteral obstruction was obtained in 100%
of diagnostic antegrade pyelography studies and in
60% of radiography or ultrasonography studies.
Conclusions and Clinical Relevance—Antegrade
pyelography can be a useful alternative in the diagnosis
and localization of ureteral obstructions in
azotemic cats, although leakage of contrast material
may prevent interpretation of the study. (J Am Vet
Med Assoc 2003;222:1576–1581)
Objective—To determine clinical, clinicopathologic,
radiographic, and ultrasonographic abnormalities in
cats with ureteral calculi.
Animals—163 client-owned cats.
Procedure—Medical records were reviewed, and
information on signalment, history, clinical signs, and
results of clinicopathologic testing and diagnostic
imaging was obtained.
Results—The number of cats in which ureterolithiasis
was diagnosed each year increased progressively during
the study period. Clinical signs tended to be nonspecific
and included inappetence, vomiting, lethargy,
and weight loss. A combination of survey radiography
and abdominal ultrasonography revealed ureteral calculi
in 66 of 73 (90%) cats in which the diagnosis was
confirmed at surgery or necropsy. Ultrasonography
revealed that ureteral calculi were causing ureteral
obstruction in 143 of 155 (92%) cats. One hundred
thirty-four of 162 (83%) cats had azotemia, 84 of 156
(54%) had hyperphosphatemia, and 22 of 152 (14%)
had hypercalcemia. Urinary tract infection was documented
in 10 of 119 (8%). Fifty-eight of 76 (76%) cats
with unilateral ureterolithiasis had azotemia and 33
(43%) had hyperphosphatemia, indicating impairment
of renal function in the contralateral kidney or prerenal
azotemia. Ultrasonographic imaging of the contralateral
kidney in cats with unilateral ureteral calculi suggested
that preexisting renal parenchymal disease
was common in cats with ureterolithiasis. Ninety-one
of 93 (98%) ureteral calculi contained calcium oxalate.
Conclusions and Clinical Relevance—Results suggest
that abdominal imaging should be performed in
all cats with chronic nonspecific signs or with acute
or chronic renal failure to rule out ureterolithiasis.
Preexisting renal disease may be common in cats
with ureteral calculi. (J Am Vet Med Assoc 2005;226: