Case Description—4 dogs were treated with dexrazoxane for known or suspected doxorubicin extravasation. Records were retrospectively reviewed. Doses and number of doses of dexrazoxane were variable. Dexrazoxane was administered within 2 hours after known extravasation in 3 dogs and 48 hours after suspected extravasation in 1 dog. Additional medical treatments included tissue cooling in all dogs, topically administered dimethyl sulfoxide ointment in 3, and orally administered piroxicam in 1.
Clinical Findings—Mild erythema and edema at the extravasation site developed within 1 to 6 days after extravasation in the 3 dogs that received dexrazoxane within 2 hours after extravasation. Extensive tissue necrosis occurred in the dog treated 48 hours after suspected extravasation.
Treatment and Outcome—Only the dog with severe tissue necrosis required surgical intervention. Lesions in the other 3 dogs resolved with medical management alone. All dogs survived the event.
Clinical Relevance—To date, use of dexrazoxane in the management of doxorubicin extravasation has not been reported in dogs. Treatment was successful in 3 of 4 patients. The most effective dosage and timing of administration are unknown; however, there is evidence to suggest that administration within 6 hours after the event is warranted. Further studies are needed to confirm efficacy and to optimize use of this drug in the prevention and treatment of anthracycline extravasation injury in veterinary patients.
Objective—To determine and compare the ratio of uracil (U) to dihydrouracil (UH2) concentrations in plasma as an indicator of dihydropyrimidine dehydrogenase activity in clinically normal dogs and dogs with neoplasia or renal insufficiency.
Animals—101 client-and shelter-owned dogs.
Procedures—Study dogs included 74 clinically normal dogs, 17 dogs with neoplasia, and 10 dogs with renal insufficiency. For each dog, a blood sample was collected into an EDTA-containing tube; plasma U and UH2 concentrations were determined via UV high-performance liquid chromatography, and the U:UH2 concentration ratio was calculated. Data were compared among dogs grouped on the basis of sex, clinical group assignment, reproductive status (sexually intact, spayed, or castrated), and age.
Results—Mean ± SEM U:UH2 concentration ratio for all dogs was 1.55 ± 0.08 (median, 1.38; range, 0.4 to 7.14). In 14 (13.9%) dogs, the U:UH2 concentration ratio was considered abnormal (ie, > 2). Overall, mean ratio for sexually intact dogs was significantly higher than that for neutered dogs; a similar difference was apparent among males but not females. Dogs with ratios > 2 and dogs with ratios ≤ 2 did not differ significantly with regard to sex, clinical group, reproductive status, or age.
Conclusions and Clinical Relevance—Determination of the U:UH2 concentration ratio was easy to perform. Ratios were variable among dogs, possibly suggesting differences in dihydropyrimidine dehydrogenase activity. However, studies correlating U:UH2 concentration ratio and fluoropyrimidine antimetabolite drug tolerability are required to further evaluate the test's validity and its appropriate use in dogs.
Animals—71 dogs with subcutaneous or intramuscular HSA.
Procedures—Medical records of affected dogs were reviewed. The following factors were evaluated for an association with outcome: dog age and sex, clinical signs, anemia, thrombocytopenia, neutrophilia, tumor stage at diagnosis, achievement of complete excision, intramuscular involvement, presence of gross disease, tumor recurrence, and treatment.
Results—Of the 71 cases identified, 16 (29%) had intramuscular tumor involvement. For all dogs, median time to tumor progression and overall survival time (OST) were 116 and 172 days, respectively; 25% survived to 1 year. Univariate analysis identified presence of clinical signs or metastasis at diagnosis, dog age, tumor size, use of any surgery, and presence of gross disease as predictors of time to tumor progression and OST. There was no significant difference in survival time between dogs with respect to type of HSA. Multivariate analysis confirmed that adequate local tumor control, tumor diameter ≤ 4 cm, presence of metastasis at diagnosis, and presence of gross disease were significantly associated with OST.
Conclusions and Clinical Relevance—Subcutaneous and intramuscular HSA remains a heterogeneous group of tumors that generally carries a poor prognosis. Adequate local control of smaller tumors with no associated clinical signs or metastasis may provide the best chance of long-term survival.
Objective—To evaluate outcomes of dogs and owner satisfaction and perception of their dogs’ adaptation following amputation of a thoracic or pelvic limb.
Design—Retrospective case series.
Animals—64 client-owned dogs.
Procedures—Medical records of dogs that underwent limb amputation at a veterinary teaching hospital between 2005 and 2012 were reviewed. Signalment, body weight, and body condition scores at the time of amputation, dates of amputation and discharge from the hospital, whether a thoracic or pelvic limb was amputated, and reason for amputation were recorded. Histologic diagnosis and date of death were recorded if applicable. Owners were interviewed by telephone about their experience and interpretation of the dog's adaptation after surgery. Associations between perioperative variables and postoperative quality of life scores were investigated.
Results—58 of 64 (91%) owners perceived no change in their dog's attitude after amputation; 56 (88%) reported complete or nearly complete return to preamputation quality of life, 50 (78%) indicated the dog's recovery and adaptation were better than expected, and 47 (73%) reported no change in the dog's recreational activities. Body condition scores and body weight at the time of amputation were negatively correlated with quality of life scores after surgery. Taking all factors into account, most (55/64 [86%]) respondents reported they would make the same decision regarding amputation again, and 4 (6%) indicated they would not; 5 (8%) were unsure.
Conclusions and Clinical Relevance—This information may aid veterinarians in educating clients about adaptation potential of dogs following limb amputation and the need for postoperative weight control in such patients. (J Am Vet Med Assoc 2015;247:786–792)
Objective—To examine the biological behavior of ulnar osteosarcoma and evaluate predictors of survival time in dogs.
Design—Retrospective case series.
Animals—30 dogs with primary ulnar osteosarcoma.
Procedures—Medical records were reviewed. Variables recorded and examined to identify predictors of survival time were signalment, tumor location in the ulna, tumor length, serum alkaline phosphatase activity, surgery type, completeness of excision, tumor stage, tumor grade, histologic subtype, development of metastases, and use of chemotherapy.
Results—30 cases were identified from 9 institutions. Eleven dogs were treated with partial ulnar ostectomy and 14 with amputation; in 5 dogs, a resection was not performed. Twenty-two dogs received chemotherapy. Median disease-free interval and survival time were 437 and 463 days, respectively. Negative prognostic factors for survival time determined via univariate analyses were histologic subtype and development of lung metastases. Telangiectatic or telangiectatic-mixed subtype (n = 5) was the only negative prognostic factor identified via multivariate analysis (median survival time, 208 days). Dogs with telangiectatic subtype were 6.99 times as likely to die of the disease.
Conclusions and Clinical Relevance—The prognosis for ulnar osteosarcoma in this population was no worse and may have been better than the prognosis for dogs with osteosarcoma involving other appendicular sites. Partial ulnar ostectomy was associated with a low complication rate and good to excellent function and did not compromise survival time. Telangiectatic or telangiectatic-mixed histologic subtype was a negative prognostic factor for survival time. The efficacy of chemotherapy requires further evaluation.