Conrado Francisco O, Weeden Amy L, Speas Abbie L, Leissinger Mary K
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Department of Small Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
Vet Clin Pathol. 2017 Sep;46(3):451-456. doi: 10.1111/vcp.12511. Epub 2017 Jun 5.
A 10-year-old, male neutered Shetland Sheepdog was presented to the University of Florida for evaluation of a well-granulated mast cell tumor. Hydroxyurea therapy was instituted and serial CBCs showed persistent mild anemia and macrocytosis without a corresponding increase in polychromasia. The dog's MCV increased progressively, reaching its highest value of 100.0 fL after 6 months of treatment, and a diagnosis of macrocytosis associated with hydroxyurea therapy was made. The dog's increase in MCV was prominent, and rapidly decreased after the drug was discontinued, consistent with previous observations in human and canine subjects treated with hydroxyurea. Hydroxyurea is a cytotoxic chemotherapeutic agent used in a variety of conditions in human and veterinary medicine, and megaloblastic changes associated with its use have been described in multiple species. This report shows that hydroxyurea treatment is a differential diagnosis for prominent macrocytosis in dogs in the absence of other signs of erythrocyte regeneration.
一只10岁已绝育的雄性设得兰牧羊犬被送到佛罗里达大学，以评估一个肉芽良好的肥大细胞瘤。开始使用羟基脲治疗，连续的全血细胞计数显示持续存在轻度贫血和大红细胞症，而多染性没有相应增加。这只狗的平均红细胞体积（MCV）逐渐增加，在治疗6个月后达到最高值100.0飞升，于是做出了与羟基脲治疗相关的大红细胞症诊断。这只狗的MCV升高很显著，在停药后迅速下降，这与之前对接受羟基脲治疗的人和犬类受试者的观察结果一致。羟基脲是一种细胞毒性化疗药物，用于人类和兽医学的多种病症，并且在多个物种中都描述了与其使用相关的巨幼细胞改变。本报告表明，在没有其他红细胞再生迹象的情况下，羟基脲治疗是犬类出现显著大红细胞症的鉴别诊断之一。
