Objective—To determine whether hydrochlorothiazide
(HCTZ) reduces urinary calcium excretion in
dogs with calcium oxalate urolithiasis.
Animals—8 dogs with calcium oxalate urolithiasis.
Procedure—4 treatment protocols were evaluated in
each dog (a low calcium, low protein diet designed to
prevent calcium oxalate urolith formation with and
without administration of HCTZ [2 mg/kg (0.9 mg/lb)
of body weight, PO, q 12 h] and a maintenance diet
with higher quantities of protein and calcium with and
without administration of HCTZ). At the end of each 2-week treatment period, 24-hour urine samples were collected. Blood samples were collected during the
midpoint of each urine collection period. Analysis of
variance was performed to evaluate the effects of
HCTZ and diet on urine and serum analytes.
Results—Hydrochlorothiazide significantly decreased
urine calcium and potassium concentration and excretion.
Hydrochlorothiazide also significantly decreased
serum potassium concentration. Compared with the
maintenance diet, the urolith prevention diet significantly
decreased urine calcium and oxalic acid concentration
and excretion. Dogs consuming the urolith
prevention diet had significantly lower serum concentrations
of albumin and urea nitrogen.
Conclusions and Clinical Relevance—Administration
of HCTZ decreased urine calcium excretion
in dogs with a history of calcium oxalate urolith formation.
The greatest reduction in urine calcium concentration
and excretion was achieved when dogs
received HCTZ and the urolith prevention diet.
Results of this study suggest that the hypocalciuric
effect of HCTZ will minimize recurrence of calcium
oxalate urolith formation in dogs; however, long-term
controlled clinical trials are needed to confirm the
safety and effectiveness of HCTZ. (J Am Vet Med
Objective—To test the hypothesis that breed, age,
sex, body condition, and environment are risk factors
for development of calcium oxalate uroliths in dogs.
Animals—1,074 dogs that formed calcium oxalate
uroliths and 1,724 control dogs that did not have
Procedure—A validated multiple-choice questionnaire
was designed to collect information from veterinarians
and owners within 1 year of the date of
urolith detection concerning signalment and environment
of the dogs. Univariate and multivariate analyses
were performed to calculate odds ratios to
assess whether breed, age, sex, body condition, and
environment were risk factors for calcium oxalate
Results—Middle-aged (8- to 12-year-old) castrated
male dogs had increased risk for formation of calcium
oxalate uroliths. Urolith formation was also associated
with increasing age. Dogs of certain breeds, including
Miniature and Standard Schnauzer, Lhasa Apso,
Yorkshire Terrier, Bichon Frise, Shih Tzu, and Miniature
and Toy Poodle, had increased risk for developing calcium
oxalate uroliths. Overweight dogs also had
Conclusions and Clinical Relevance—Knowledge of
patient and environmental risk factors for development
of calcium oxalate uroliths may facilitate development
of surveillance strategies that result in earlier
detection of this disease. Modification of environmental
factors and body weight may minimize calcium
oxalate urolith formation and recurrence. (J Am
Vet Med Assoc 2000;217:515–519)
Animals—131 client-owned dogs with stable chronic osteoarthritis examined at 33 privately owned veterinary hospitals in the United States.
Procedures—In all dogs, the dosage of carprofen was standardized over a 3-week period to approximately 4.4 mg/kg/d (2 mg/lb/d), PO. Dogs were then randomly assigned to receive a food supplemented with fish oil omega-3 fatty acids or a control food with low omega-3 fatty acid content, and 3, 6, 9, and 12 weeks later, investigators made decisions regarding increasing or decreasing the carprofen dosage on the basis of investigator assessments of 5 clinical signs and owner assessments of 15 signs.
Results—Linear regression analysis indicated that over the 12-week study period, carprofen dosage decreased significantly faster among dogs fed the supplemented diet than among dogs fed the control diet. The distribution of changes in carprofen dosage for dogs in the control group was significantly different from the distribution of changes in carprofen dosage for dogs in the test group.
Conclusions and Clinical Relevance—Results suggested that in dogs with chronic osteoarthritis receiving carprofen because of signs of pain, feeding a diet supplemented with fish oil omega-3 fatty acids may allow for a reduction in carprofen dosage.
Objective—To determine whether high systolic blood
pressure (SBP) at the time of initial diagnosis of
chronic renal failure in dogs was associated with
increased risk of uremic crisis, risk of dying, or rate of
decline in renal function.
Design—Prospective cohort study.
Animals—45 dogs with spontaneous chronic renal
Procedure—Dogs were assigned to 1 of 3 groups on
the basis of initial SBP (high, intermediate, low);
Kaplan-Meier and Cox proportional hazards methods
were used to estimate the association between SBP
and development of a uremic crisis and death. The
reciprocal of serum creatinine concentration was
used as an estimate of renal function.
Results—Dogs in the high SBP group were more
likely to develop a uremic crisis and to die than were
dogs in the other groups, and the risks of developing
a uremic crisis and of dying increased significantly as
SBP increased. A greater decrease in renal function
was observed in dogs in the high SBP group.
Retinopathy and hypertensive encephalopathy were
detected in 3 of 14 dogs with SBP ≥ 180 mm Hg.
Systolic blood pressure remained high in 10 of 11
dogs treated with antihypertensive drugs.
Conclusions and Clinical Relevance—Results suggested
that initial high SBP in dogs with chronic renal
failure was associated with increased risk of developing
a uremic crisis and of dying. Further studies are
required to determine whether there is a cause-and-effect
relationship between high SBP and progressive
renal injury and to identify the risks and benefits of
antihypertensive drug treatment. (J Am Vet Med Assoc 2003;222:322–329)
Objective—To determine whether urine protein-to-creatinine
ratio (UP:C) ≥ 1.0 at initial diagnosis of
chronic renal failure (CRF) is associated with greater
risk of development of uremic crises, death, and progression
of renal failure in dogs.
Design—Prospective cohort study.
Animals—45 dogs with CRF.
Procedure—Dogs were prospectively assigned to 2
groups on the basis of initial UP:C < 1.0 or ≥ 1.0. The
association between magnitude of proteinuria and
development of uremic crises and death was determined
before and after dogs with initial UP:C ≥ 1.0
were assigned to 3 subgroups and compared with
dogs with initial UP:C < 1.0. Changes in reciprocal
serum creatinine concentration were used to estimate
decrease in renal function.
Results—Initially, dogs had similar clinical characteristics
with the exception of systolic blood pressure
and UP:C. Relative risks of development of uremic
crises and death were approximately 3 times higher
in dogs with UP:C ≥ 1.0, compared with dogs with
UP:C < 1.0. Relative risk of adverse outcome was
approximately 1.5 times higher for every 1-unit increment
in UP:C. The decrease in renal function was of
greater magnitude in dogs with UP:C ≥ 1.0, compared
with dogs with UP:C < 1.0.
Conclusions and Clinical Relevance—Initial UP:C
≥ 1.0 in dogs with CRF was associated with greater
risk of development of uremic crises and death, compared
with dogs with UP:C < 1.0. Initial determinations
of UP:C in dogs with naturally occurring CRF
may be of value in refining prognoses. (J Am Vet Med
Objective—To determine whether a diet used for
dogs with renal failure (renal food [RF]) was superior
to an adult maintenance food (MF) in minimizing uremic
crises and mortality rate in dogs with spontaneous
chronic renal failure.
Animals—38 dogs with spontaneous chronic renal
Procedure—Dogs were randomly assigned to a group
fed adult MF or a group fed RF and evaluated for up to
24 months. The 2 groups were of similar clinical, biochemical,
and hematologic status. The effects of diets
on uremic crises and mortality rate were compared.
Changes in renal function were evaluated by use of serial
evaluation of serum creatinine concentrations and
reciprocal of serum creatinine concentrations.
Results—Compared with the MF, the RF had a beneficial
effect regarding uremic crises and mortality rate
in dogs with mild and moderate renal failure. Dogs
fed the RF had a slower decline in renal function,
compared with dogs fed the MF.
Conclusions and Clinical Relevance—Dietary
modifications are beneficial in minimizing extrarenal
manifestations of uremia and mortality rate in dogs
with mild and moderate spontaneous chronic renal
failure. Results are consistent with the hypothesis
that delay in development of uremic crises and associated
mortality rate in dogs fed RF was associated,
at least in part, with reduction in rate of progression
of renal failure. (J Am Vet Med Assoc 2002;220:
Animals—38 client-owned dogs with osteoarthritis examined at 2 university veterinary clinics.
Procedures—Dogs were randomly assigned to receive a typical commercial food (n = 16) or a test food (22) containing 3.5% fish oil omega-3 fatty acids. On day 0 (before the trial began) and days 45 and 90 after the trial began, investigators conducted orthopedic evaluations and force-plate analyses of the most severely affected limb of each dog, and owners completed questionnaires to characterize their dogs' arthritis signs.
Results—The change in mean peak vertical force between days 90 and 0 was significant for the test-food group (5.6%) but not for the control-food group (0.4%). Improvement in peak vertical force values was evident in 82% of the dogs in the test-food group, compared with 38% of the dogs in the control-food group. In addition, according to investigators' subjective evaluations, dogs fed the test food had significant improvements in lameness and weight bearing on day 90, compared with measurements obtained on day 0.
Conclusions and Clinical Relevance—At least in the short term, dietary supplementation with fish oil omega-3 fatty acids resulted in an improvement in weight bearing in dogs with osteoarthritis.
Animals—127 client-owned dogs with osteoarthritis in 1 or more joints from 18 privately owned veterinary clinics.
Procedures—Dogs were randomly assigned to be fed for 6 months with a typical commercial food or a test food containing a 31-fold increase in total omega-3 fatty acid content and a 34-fold decrease in omega-6–omega-3 ratio, compared with the control food. Dog owners completed a questionnaire about their dog's arthritic condition, and investigators performed a physical examination and collected samples for a CBC and serum biochemical analyses (including measurement of fatty acids concentration) at the onset of the study and at 6, 12, and 24 weeks afterward.
Results—Dogs fed the test food had a significantly higher serum concentration of total omega-3 fatty acids and a significantly lower serum concentration of arachidonic acid at 6, 12, and 24 weeks. According to owners, dogs fed the test food had a significantly improved ability to rise from a resting position and play at 6 weeks and improved ability to walk at 12 and 24 weeks, compared with control dogs.
Conclusions and Clinical Relevance—Ingestion of the test food raised blood concentrations of omega-3 fatty acids and appeared to improve the arthritic condition in pet dogs with osteoarthritis.