Objectives—To assess the effect of increasing serum
lithium concentrations on lithium dilution cardiac output
(LiDCO) determination and to determine the ability
to predict the serum lithium concentration from the
cumulative lithium chloride dosage.
Animals—10 dogs (7 males, 3 females).
Procedure—Cardiac output (CO) was determined in
anesthetized dogs by measuring LiDCO and thermodilution
cardiac output (TDCO). The effect of the
serum lithium concentration on LiDCO was assessed
by observing the agreement between TDCO and
LiDCO at various serum lithium concentrations. Also,
cumulative lithium chloride dosage was compared
with the corresponding serum lithium concentrations.
Results—44 paired observations were used. The linear
regression analysis for the effect of the serum
lithium concentration on the agreement between
TDCO and LiDCO revealed a slope of -1.530 (95%
confidence interval [CI], -2.388 to -0.671) and a yintercept
of 0.011 (r2 = 0.235). The linear regression
analysis for the effect of the cumulative lithium chloride
dosage on the serum lithium concentration
revealed a slope of 2.291 (95% CI, 2.153 to 2.429)
and a y-intercept of 0.008 (r2 = 0.969).
Conclusions and Clinical Relevance—The LiDCO
measurement increased slightly as the serum lithium
concentration increased. This error was not clinically
relevant and was minimal at a serum lithium concentration
of 0.1 mmol/L and modest at a concentration
of 0.4 mmol/L. The serum lithium concentration can
be reliably predicted from the cumulative lithium
dosage if lithium chloride is administered often within
a short period. (Am J Vet Res 2002;63:1048–1052)
Objectives—To determine agreement of cardiac output
measured by use of lithium dilution cardiac output
(LiDCO) and thermodilution cardiac output (TDCO)
techniques in dogs and to determine agreement of
low- and high-dose LiDCO with TDCO.
Animals—10 dogs (7 males, 3 females).
Procedure—Cardiac output was measured in anesthetized
dogs by use of LiDCO and TDCO techniques.
Four rates of cardiac output were induced by occlusion
of the caudal vena cava, changes in depth of
anesthesia, or administration of dobutamine. Lithium
dilution cardiac output was performed, using 2 doses
of lithium chloride (low and high dose). Each rate of
cardiac output allowed 4 comparisons between
LiDCO and TDCO.
Results—160 comparisons were determined of
which 68 were excluded. The remaining 92 comparisons
had values ranging from 1.10 to 12.80 L/min.
Intraclass correlation coefficient (ICC) between lowdose
LiDCO and TDCO was 0.9898 and between
high-dose LiDCO and TDCO was 0.9896. When all
LiDCO determinations were pooled, ICC was 0.9894.
For determinations of cardiac output < 5.0 L/min, ICC
was 0.9730. Mean ± SD of the differences of TDCO
minus LiDCO for all measurements was -0.084 ±
0.465 L/min, and mean of TDCO minus LiDCO for cardiac
outputs < 5.0 L/min was -0.002 ± 0.245 L/min.
Conclusions and Clinical Relevance—The LiDCO
technique is a suitable substitute for TDCO to measure
cardiac output in dogs. Use of LiDCO eliminates
the need for catheterization of a pulmonary artery and
could increase use of cardiac output monitoring,
which may improve management of cardiovascularly
unstable animals. (Am J Vet Res 2001;62:1255–1261)
OBJECTIVE To determine the effectiveness of metronomic cyclophosphamide (MC) chemotherapy (primary treatment of interest) with adjuvant meloxicam administration as maintenance treatment for dogs with appendicular osteosarcoma following limb amputation and carboplatin chemotherapy.
DESIGN Retrospective case series with nested cohort study.
ANIMALS 39 dogs with a histologic diagnosis of appendicular osteosarcoma that underwent limb amputation and completed carboplatin chemotherapy from January 2011 through December 2015.
PROCEDURES Dogs were grouped by whether carboplatin chemotherapy had been followed with or without MC chemotherapy (15 mg/m2, PO, q 24 h) and meloxicam (0.1 mg/kg [0.045 mg/lb], PO, q 24 h). The Breslow rank test was used to assess whether MC chemotherapy was associated with overall survival time (OST) and disease progression-free time (PFT) after limb amputation.
RESULTS 19 dogs received carboplatin and MC chemotherapy, and 20 dogs received only carboplatin chemotherapy. No differences were identified between these groups regarding age, reproductive status, body weight, serum alkaline phosphatase activity, tumor location, or histologic grade or subtype of osteosarcoma. Median duration of MC chemotherapy for dogs in the carboplatin-MC group was 94 days (range, 7 to 586 days); this treatment was discontinued for 11 (58%) dogs when cystitis developed. Overall, 11 (28%) dogs survived to the time of analysis, for a median follow-up period of 450 days (range, 204 to 1,400 days). No difference in median PFT or OST was identified between the 2 groups.
CONCLUSIONS AND CLINICAL RELEVANCE Maintenance MC chemotherapy following limb amputation and completed carboplatin chemotherapy was associated with no increase in PFT or OST in dogs with appendicular osteosarcoma. Cystitis was common in MC-treated dogs, and prophylactic treatment such as furosemide administration could be considered to reduce the incidence of cystitis in such dogs.
Objective—To determine the efficacy and toxic effects of epirubicin for the adjuvant treatment of dogs with splenic hemangiosarcoma and identify prognostic factors.
Design—Retrospective case series.
Animals—59 client-owned dogs that underwent splenectomy for splenic hemangiosarcoma treated with or without epirubicin.
Procedures—Medical records were examined for signalment, clinical signs, diagnostic and surgical findings, and postoperative outcome. For dogs treated with epirubicin, dose numbers, intervals, and reductions and type and severity of toxic effects were recorded. Dogs were allotted to 2 groups: splenectomy alone and splenectomy with adjuvant epirubicin treatment.
Results—18 dogs received epirubicin (30 mg/m2) every 3 weeks for up to 4 to 6 treatments. Forty-one dogs were treated with splenectomy alone. The overall median survival time was significantly longer in dogs treated with splenectomy and epirubicin (144 days), compared with splenectomy alone (86 days). Median survival time for dogs with stage I disease (345 days) was significantly longer than for dogs with either stage II (93 days) or III disease (68 days). Seven of 18 dogs treated with epirubicin were hospitalized for signs of adverse gastrointestinal effects. Inappetence, long duration of clinical signs, thrombocytopenia, neutrophilia, and high mitotic rate were negative prognostic factors.
Conclusions and Clinical Relevance—Epirubicin may be as efficacious as adjuvant doxorubicin-based protocols, but may result in a higher incidence of adverse gastrointestinal effects. Epirubicin should be considered as an alternative to doxorubicin in dogs with preexisting cardiac disease, as clinical epirubicin cardiotoxicity was not diagnosed in treated dogs.
Objective—To quantitatively determine echogenicity
of the liver and renal cortex in clinically normal cats.
Animals—17 clinically normal adult cats.
Procedure—3 ultrasonographic images of the liver and
the right kidney were digitized from video output from
each cat. Without changing the ultrasound machine
settings, an image of a tissue-equivalent phantom was
digitized. Biopsy specimens of the right renal cortex
and liver were obtained for histologic examination.
Mean pixel intensities within the region of interest
(ROI) on hepatic, renal cortical, and tissue-equivalent
phantom ultrasonographic images were determined by
histogram analysis. From ultrasonographic images,
mean pixel intensities for hepatic and renal cortical ROI
were standardized by dividing each mean value by the
mean pixel intensity from the tissue-equivalent phantom.
Results—The mean (± SD) standardized hepatic
echogenicity value was 1.06 ± 0.02 (95% confidence
interval, 1.02 to 1.10). The mean standardized right
renal cortical echogenicity value was 1.04 ± 0.02
(95% confidence interval, 1.01 to 1.08). The mean
combined standardized hepatic and renal cortical
echogenicity value was 1.02 ± 0.05 (95% confidence
interval, 0.99 to 1.04).
Conclusions and Clinical Relevance—Quantitative
determination of hepatic and renal cortical echogenicity
in cats is feasible, using histogram analysis, and
may be useful for early detection of diffuse parenchymal
disease and for serially evaluating disease progression.
(Am J Vet Res 2000;61:1016–1020)
Objective—To determine the prevalence of
Trypanosoma cruzi infection among dogs in Oklahoma.
Animals—301 owned or impounded dogs related by
ownership or general geographic location to 3 dogs
determined to have trypanosomiasis.
Procedure—Blood samples were obtained from
dogs between November 1996 and September 1997.
Infection status was determined by use of a radioimmunoprecipitation
assay. Second blood samples were
obtained from some of the seropositive dogs for
study by hemoculture and polymerase chain reaction
(PCR) assay. Sites where infected dogs were found
were inspected for triatomine insects, and light traps
were used for vector trapping.
Results—11(3.6%) dogs were seropositive for T cruzi
infection. Ten of the 11 were owned rural hunting
dogs. Protozoal organisms isolated from the blood of
1 seropositive dog were identified as T cruzi by PCR
testing. Only 1 adult Triatoma sanguisugai was captured
in a light trap at a site near infected dogs; this
insect was not infected.
Conclusion and Clinical Relevance—Our findings
suggest that T cruzi is enzootic in eastern Oklahoma.
Measures that would reduce the risk of dogs acquiring
T cruzi infection are unlikely to be acceptable to
their owners, and no effective drugs are available for
treatment. The presence of T cruzi-infected dogs
poses a threat of transmission to persons at risk of
exposure to contaminated blood. Veterinarians who
practice in the southern United States should be cognizant
of this blood borne zoonosis and educate all
personnel about appropriate precautions. (J Am Vet
Med Assoc 2000;217:1853–1857)
Case Description—A 1.5-year-old spayed female domestic shorthair cat was admitted for hind limb locomotor difficulties and signs of pain along the lumbar portion of the vertebral column. At the time of referral, the cat was paraparetic with deficits in the spinal reflexes of the hind limbs. Neuroanatomic localization was at the L6-S2 spinal cord segments, corresponding approximately to the region of the L4-L6 vertebral bodies.
Clinical Findings—Radiography revealed a mixed osteolytic-proliferative lesion within the body of L5 involving the cranial end plate, as well as punctate radiolucencies in the distal portion of the femur. Magnetic resonance imaging revealed an intramedullary spinal cord lesion along with extensive meningeal and nerve root lesions in the area of the L4-L6 vertebral bodies. Cytologic analysis of a bone marrow aspirate from the right trochanteric fossa revealed a substantial plasma cell infiltrate. Analysis of CSF revealed a high protein concentration and morphologically abnormal plasma cells. Urine, but not serum, protein electrophoresis revealed a sharp γ-globulin peak consistent with a monoclonal band of Bence-Jones proteins. The diagnosis was multiple myeloma.
Treatment and Outcome—The cat was treated with melphalan and prednisolone. A rapid clinical response was reported, and by week 3 after diagnosis, the cat's locomotion and behavior had normalized. However, by month 4, multifocal neurologic deficits were evident. The cat was euthanized at 9 months because of tetraparesis and substantial weight loss.
Clinical Relevance—To our knowledge, this is the first report of myeloma in a cat that had electrophoretically detectable light chain proteinuria but lacked a detectable serum monoclonal gammopathy.