OBJECTIVE To evaluate factors for associations with duration of first remission and survival time in dogs ≥ 14 years of age with stage III to V multicentric lymphoma.
DESIGN Retrospective cohort study.
ANIMALS 29 dogs ≥ 14 years of age with multicentric lymphoma treated with a chemotherapy protocol at dosages used for younger dogs (n = 22) or with prednisolone alone (7).
PROCEDURES Various data were collected from the medical records, including treatment response and related adverse events. Survival analysis was performed to determine duration of first remission and survival time (from start of chemotherapy), and these outcomes were compared between various groupings.
RESULTS The 7 (24%) dogs that received prednisolone alone had a median survival time of 27 days and were excluded from further analysis. Complete clinical remission was achieved in 21 of the 22 (95%) remaining dogs; 1 (5%) achieved partial remission. Median duration of first remission was 181 days. Anemic dogs had a briefer remission period (median, 110 days) than nonanemic dogs (median, 228 days). Median survival time for all 22 dogs was 202 days, with estimated 1- and 2-year survival rates of 31% and 5%, respectively. Six (27%) dogs had adverse events of chemotherapy classified as grade 3 or worse.
CONCLUSIONS AND CLINICAL RELEVANCE Survival time was substantially longer in dogs treated with a chemotherapy protocol versus prednisolone alone. Findings suggested that the evaluated chemotherapy protocols for lymphoma were beneficial for and tolerated by very elderly dogs, just as by younger dogs, and need not be withheld, or dosages adjusted, because of age alone.
OBJECTIVE To determine histologic and clinical factors associated with survival time in dogs with stage II splenic hemangiosarcoma treated by splenectomy and a chemotherapy protocol in which an anthracycline was alternated with lomustine.
DESIGN Retrospective case series.
ANIMALS 30 dogs with stage II splenic hemangiosarcoma.
PROCEDURES Medical records of 3 facilities were reviewed to identify dogs treated for stage II splenic hemangiosarcoma between June 2011 and October 2014. Information collected included signalment, disease staging data, whether anemia was present, date of splenectomy, chemotherapy protocol, adverse effects, and date of death or last follow-up. Histologic slides were reviewed and scored by pathologists. Associations between variables of interest and survival data were evaluated statistically.
RESULTS Median survival time for all dogs was 158 days (range, 55 to 560 days), and the 1-year survival rate was 16%. On multivariate analysis, only the histologically determined mitotic score was significantly associated with survival time. The median survival time of 292 days for dogs with a mitotic score of 0 (< 11 mitoses/10 hpf; n = 9) was significantly longer than that for dogs with higher scores (indicating higher mitotic rates); the 1-year survival rate for these dogs was 42%.
CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that future studies should take histologic factors, particularly mitotic rate, as well as tumor stage into account when assessing treatment effects on survival time of dogs with splenic hemangiosarcoma.
OBJECTIVE To estimate survival time for dogs with small intestinal adenocarcinoma (SIACA) following tumor excision with or without adjuvant chemotherapy and to identify factors associated with survival time.
DESIGN Retrospective case series with a nested cohort study.
ANIMALS 29 client-owned dogs with surgically resected, histologically diagnosed SIACA.
PROCEDURES Medical records were reviewed and data collected regarding dog signalment; clinical signs; physical examination findings; PCV; serum total solids concentration; diagnostic imaging results; tumor size, location, and histologic characteristics (serosal extension, lymphatic invasion, surgical margins, and lymph node metastasis); type of adjuvant chemotherapy; NSAID administration; and survival time. Variables were assessed for associations with survival time and hazard rate via Kaplan-Meier and Cox proportional hazards analyses.
RESULTS Overall median survival time for dogs with SIACA following tumor excision was 544 days (95% confidence interval, 369 to 719 days). Based on Kaplan-Meier estimates, the 1- and 2-year survival rates were 60% and 36%, respectively. On multivariate analysis, only age category was an independent predictor of survival over the follow-up period. Dogs < 8 years of age had a significantly longer median survival time (1,193 days) than dogs ≥ 8 years (488 days). Lymph node metastasis, adjuvant chemotherapy, NSAID administration, and other assessed variables were not associated with survival time.
CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that SIACA in dogs carries a fair prognosis following excision, even when lymph node metastasis is present. Prospective studies are warranted to better characterize the effects of adjuvant chemotherapy or NSAID administration on survival time.
OBJECTIVE To determine the incidence of sterile hemorrhagic cystitis (SHC) in tumor-bearing dogs concurrently treated with oral metronomic cyclophosphamide chemotherapy and furosemide.
DESIGN Retrospective case series.
ANIMALS 55 dogs.
PROCEDURES Record databases of 2 specialty practices were searched to identify dogs treated with oral metronomic cyclophosphamide chemotherapy in conjunction with furosemide for a minimum of 28 days between January 2009 and December 2015. Information extracted from the records included signalment, tumor diagnosis, cyclophosphamide and furosemide dosages, and concurrent medications. Confirmed SHC was defined as the presence of gross or microscopic hematuria and clinical signs associated with lower urinary tract disease in the absence of infection or neoplasia of the urinary tract; the definition for suspected SHC was the same, except the absence of infection or neoplasia of the urinary tract was not confirmed.
RESULTS Cyclophosphamide dosage varied from 6.5 to 18.6 mg/m2 once daily to 6.3 to 49.2 mg/m2 every other day. Median duration of cyclophosphamide administration was 272 days (range, 28 to 1,393 days). Median cumulative dose of cyclophosphamide administered was 2,898 mg/m2 (range, 224 to 14,725 mg/m2). Median furosemide dose was 1.4 mg/kg (0.64 mg/lb). Confirmed or suspected SHC was identified in 2 of 55 (3.6%) dogs. Cyclophosphamide administration was discontinued for the dog with confirmed SHC but not the dog with suspected SHC.
CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that oral administration of furosemide in conjunction with oral metronomic cyclophosphamide chemotherapy was associated with a low incidence of SHC, which suggested that furosemide may protect against cyclophosphamide-induced SHC.
Objective—To examine characteristics of cats and
their owners with regard to outdoor access of owned
Animals—184 owned cats admitted to a veterinary
referral center for nonemergency health concerns.
Results—Cats acquired recently were less likely to
be allowed outdoors than those acquired during previous
years. Outdoor access was often limited during
the day; few owners allowed their cats to remain outdoors
at night. Cats acquired from shelters were
more likely to be kept exclusively as indoor pets than
those cats acquired as strays. The presence of dogs
but not other cats in the household was associated
with increased outdoor access. Age, health status,
and onychectomy status were not significantly associated
with outdoor access. Cats allowed outdoor
access were more likely to have been bitten by other
Conclusions and Clinical Relevance—The basis for
an owner's decision to allow outdoor access appears
to be multifactorial, and there may be regional differences
in outdoor access of owned cats. Acquisition
source is associated with outdoor access of owned
cats. Availability of information regarding outdoor
access of cats may influence decision making.
Educational efforts targeted at specific groups of cat
owners, as well as programs that acknowledge owner
beliefs regarding quality of life for their cats, may help
to address the health, safety, and population concerns
associated with outdoor access of owned cats.
(J Am Vet Med Assoc 2003;222:15417–1545)
Objective—To evaluate survival times and palliative effects associated with the use of samarium Sm 153 lexidronam in dogs with primary bone tumors.
Design—Retrospective case series.
Animals—35 dogs with primary appendicular (n = 32) or axial (3) bone tumors.
Procedures—1 to 4 doses of samarium Sm 153 lexidronam were administered at a rate of 37 MBq/kg (16.8 MBq/lb), IV. Response to treatment, measured by lameness improvement, and survival time were determined.
Results—Of the 32 dogs with appendicular tumors, 20 (63%) had an improvement in the severity of lameness 2 weeks after administration of the first dose of radioactive samarium, 8 (25%) had no change in the severity of lameness, and 4 (12%) had a worsening. Overall median survival time was 100 days, with 3 dogs (8.6%) alive after 1 year. Median survival time for the 32 dogs with appendicular tumors was 93 days, with 3 (9.4%) alive after 1 year. This was not significantly different from the median survival time of 134 days for a historical cohort of 162 dogs with appendicular osteosarcoma that underwent amputation as the only treatment.
Conclusions and Clinical Relevance—Results suggest that samarium Sm 153 lexidronam may be useful in the palliation of pain in dogs with primary bone tumors that are not candidates for curative-intent treatment.
Objective—To determine the maximally tolerated dose (MTD) and dose-limiting toxicosis (DLT) of ifosfamide in tumor-bearing cats.
Animals—38 cats with resected, recurrent, or metastatic sarcomas.
Procedure—The starting dosage of ifosfamide was 400 mg/m2 of body surface area, IV, and dosages were increased by 50 to 100 mg/m2 in cohorts of 3 cats. To protect against urotoxicosis, mesna was administered at a dosage equal to 20% of the calculated ifosfamide dosage. Diuresis with saline (0.9% NaCl) solution before and after administration of ifosfamide was used to minimize nephrotoxicosis. Samples for pharmacokinetic analysis were obtained after the MTD was reached.
Results—38 cats were entered into this phase I study and were administered a single dose of ifosfamide at various dosages. The MTD was 1,000 mg/m2, and neutropenia was the DLT. Seven of 8 episodes of neutropenia were on day 7 after treatment, and 1 cat developed severe neutropenia on day 5. Adverse effects on the gastrointestinal tract were generally mild and self-limiting, the most common of which was nausea during ifosfamide infusion. One cat had signs consistent with a drug-induced hypersensitivity reaction. There were no episodes of hemorrhagic cystitis or nephrotoxicosis. Correlations between pharmacokinetic variables and ifosfamide-associated toxicoses were not found. Preliminary evidence of antitumor activity was observed in 6 of 27 cats with measurable tumors.
Conclusions and Clinical Relevance—The dosage of ifosfamide recommended to treat tumor-bearing cats is 900 mg/m2 every 3 weeks. This dosage should be used in phase II clinical trials.
Objective—To determine toxic effects of streptozocin
given in combination with a diuresis protocol in dogs
and establish whether streptozocin is efficacious in
treatment of pancreatic islet cell tumors in dogs.
Procedure—Medical records were reviewed to
obtain information regarding signalment, tumor stage
and staging tests performed, number of streptozocin
treatments, adverse effects, results of biochemical
and hematologic monitoring during streptozocin treatment,
tumor dimensions, duration of normoglycemia,
and date of death, when applicable. Dogs were compared
with a historical control group of 15 dogs treated
surgically and medically.
Results—58 treatments were administered to the 17
dogs. Only 1 dog developed azotemia. Serum alanine
aminotransferase activity increased in some dogs but
decreased when treatment was discontinued.
Hematologic toxicoses were rare. Vomiting during
administration was uncommon but occasionally
severe. Two dogs developed diabetes mellitus after
receiving 5 doses. Median duration of normoglycemia
for 14 dogs with stage-II or -III insulinoma treated with
streptozocin was 163 days (95% confidence interval,
16 to 309 days), which was not significantly different
from that for the control dogs (90 days; 95% confidence
interval, 0 to 426 days). Two dogs had rapid resolution
of paraneoplastic peripheral neuropathy, and 2
others had measurable reductions in tumor size.
Conclusions and Clinical Relevance—Results
suggest that streptozocin can be administered safely
to dogs at a dosage of 500 mg/m2, IV, every 3
weeks when combined with a protocol for induction
of diuresis and may be efficacious in the treatment
of dogs with metastatic pancreatic islet cell tumors.
(J Am Vet Med Assoc 2002;221:811–818)
CASE DESCRIPTION 4 dogs with a slow-growing mass in the cervical region were evaluated.
CLINICAL FINDINGS All dogs had no clinical signs at the time of the evaluation. There was no apparent evidence of visceral metastases or other primary tumor based on available CT or MRI data for any dog.
TREATMENT AND OUTCOME For each dog, surgery to remove the mass was performed. Histologic examination of the excised tissue revealed a completely excised grade 1 or 2 lymph node hemangiosarcoma. All dogs received adjuvant chemotherapy; 2 dogs underwent curative intent chemotherapy, 1 dog underwent metronomic treatment with cyclophosphamide, and 1 dog underwent metronomic treatment with chlorambucil. The survival time was 259 days in 1 dog; 3 dogs were still alive 615, 399, and 365 days after surgery.
CLINICAL RELEVANCE Primary nodal hemangiosarcoma in dogs is a rare and, to the authors' knowledge, previously undescribed disease that appears to develop in the cervical lymph nodes as a slow-growing mass or masses. Surgical excision and adjunct treatment resulted in long survival times for 3 of the 4 dogs of the present report. Given the aggressive biologic behavior of hemangiosarcomas in other body locations, adjunct chemotherapy should be considered for affected dogs, although its role in the cases described in this report was unclear. Additional clinical information is required to further characterize the biologic behavior of this tumor type and determine the expected survival times and associated risk factors in dogs.
Objective—To evaluate response rate and duration of
malignant melanomas in dogs treated with carboplatin.
Animals—27 client-owned dogs with spontaneously
occurring measurable malignant melanomas.
Procedure—Records of dogs with melanomas treated
with carboplatin from October 1989 to June 2000
were reviewed. Carboplatin was administered IV at
doses of 300 or 350 mg/m2 of body surface area.
Response to treatment and evidence of drug toxicity
Result—Response to treatment could be evaluated in
25 dogs. Of those, overall response rate was 28%.
One dog had a complete response, 6 (24%) dogs had
a partial response (> 50% reduction in tumor burden).
Median duration of partial response was 165 days.
Eighteen dogs had stable disease (n = 9; 36%) or progressive
disease (9; 36%). Response to treatment
was significantly associated with carboplatin dose on
a milligram per kilogram basis (15.1 mg/kg [6.9 mg/lb]
of body weight vs 12.6 mg/kg [5.7 mg/lb]). Evidence
of gastrointestinal toxicosis could be assessed in 27
dogs. Mean body weight of 5 dogs that developed
gastrointestinal toxicosis was significantly less than
that of 22 dogs without gastrointestinal toxicosis (9.9
kg [21.8 lb] vs 19.3 kg [42.5 lb]).
Conclusions and Clinical Relevance—Carboplatin
had activity against macroscopic spontaneously
occurring malignant melanomas in dogs and should
be considered as an adjunctive treatment for microscopic
local or metastatic tumors. Gastrointestinal
toxicosis was associated with body weight. Because
small dogs are more likely to have adverse gastrointestinal
effects, gastrointestinal protectants should be
considered for these patients. (J Am Vet Med Assoc