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
Objective—To determine the prognostic factors for
survival and tumor recurrence in dogs with cutaneous
mast cell tumors (MCTs) in the perineal and inguinal
regions treated surgically with or without adjunctive
radiation therapy, chemotherapy, or both.
Procedure—Medical records of dogs with histologically
confirmed MCTs in the perineal region, inguinal
region, or both treated surgically with or without
adjunctive radiation therapy, chemotherapy, or both
Results—Mean tumor-free interval was 1,635 days
(median not reached), and 1- and 2-year tumor-free
rates were 79% and 71%, respectively. Median survival
time was 1,111 days (mean, 1,223 days), and 1-
and 2-year survival rates were 79% and 61%, respectively.
Factors that negatively influenced survival time
were age at diagnosis, tumor recurrence, and treatment
Conclusions and Clinical Relevance—Results indicated
that dogs with MCTs in the inguinal and perineal
regions, if appropriately treated, may have survival
times and tumor-free intervals similar to dogs
with MCTs in other locations. ( J Am Vet Med Assoc