Carboplatin-Induced Myelosuppression As Related To Body Weight In Dogs.

Smaller dogs are known to have an increased risk of chemotherapy-induced myelosuppression for doxorubicin, mitoxantrone, and melphalan. This retrospective study aimed to determine if dogs <15 kg and <10 kg experienced greater degrees of myelosuppression following treatment with carboplatin chemotherapy compared to dogs ≥15 kg. One hundred and one dogs treated with carboplatin for a variety of malignancies were retrospectively analyzed. Eight dogs (61%) weighing <10 kg, three (38%) weighing 10 kg to <15 kg, and 14 (17%) weighing ≥15 kg experienced a grade 3 or 4 neutropenia. Five dogs (38%) weighing <10 kg, two (25%) weighing 10 kg to <15 kg, and 13 (16%) weighing ≥15 kg experienced a grade 3 or 4 thrombocytopenia. Dogs <10 kg were significantly more likely to develop a grade 3 or 4 neutropenia following carboplatin than dogs ≥10 kg (3.5 RR; 95% CI, 1.9-6.3; p <0.001). Dogs <15 kg were also significantly more likely to develop a grade 3 or 4 neutropenia than dogs ≥15 kg (3 RR; 95% CI, 1.6-5.6; p=0.004). Dogs <10 kg were significantly more likely to develop a grade 3 or 4 thrombocytopenia than those dogs ≥10 kg (2.5 RR; 95% CI, 1.1-5.6; p=0.006 ). Hospitalization was significantly more likely for dogs <10 kg versus ≥10 kg (p=0.014) as well as for dogs <15 kg versus ≥15 kg (p=0.039). This study demonstrates an increased risk of carboplatin-induced myelosuppression in dogs <15 kg, and particularly those <10 kg. This information should be considered by clinicians when making decisions regarding the initial carboplatin dose for smaller canine patients, especially those <15 kg. This article is protected by copyright. All rights reserved.