Bone Marrow and Peripheral Blood of Cats: Technique and Normal Values

Examination of bone marrow and peripheral blood is necessary to diagnose and study many diseases affecting the hematopoietic system of cats. A simplified technique for obtaining marrow from cats, modified from a previously reported method, employs local anesthesia and minimal restraint. Skin and periosteum over the iliac crest are anesthetized with 2% procaine; a 3/4-inch, 18 gauge needle with short beveled point and seated stylet is introduced into the ilium through a small skin incision. Marrow is aspirated with a syringe and smears are made directly. Wright and Giemsa stains are used and 500 nucleated cells are differentiated. Average differential values on marrow from 15 clinically normal cats were: rubriblast 1.2%, prorubricyte 2.8%, rubricyte 16.1%, metarubricyte 18.2%, (total erythrocytic cells, 38.4%), myeloblast 1.1%, progranulocyte 2.8%, neutrophil myelocyte 5.9%, eosinophil myelocyte 0.3%, neutrophil metamyelocyte 15.0%, eosinophil metamyelocyte 0.2%, neutrophil band 14.7%, eosinophil band 0.3%, neutrophil segmenter 14.0%, eosinophil segmenter 1.3% (total myelocytic cells, 55.6%), lymphocytes 5.1%, plasma cells 0.5%, reticulum cells 0.3%. The average myeloid: erythroid ratio was 1.6:1. Peripheral blood for determining hematocrits (PCV), total leukocyte counts (WBC) and differential leukocyte counts on the same animals was obtained by puncturing the marginal ear vein. Average values for these determinations were: PCV 37%, WBC 15,250/cmm., segmenters (neutrophil) 59%, bands (neutrophil) 4%, eosinophils 6%, lymphocytes 27%, monocytes 3%. Terminology used to classify the cells described and illustrated in this report is that recommended by the Committee for Clarification of the Nomenclature of Cells and Diseases of the Blood and Blood-Forming Organs.