A study of hematology, serum biochemistry, and physical parameters of white-tailed deer Cades Cove, Great Smoky Mountains National Park

Blood samples were collected from 203 white-tailed deer (Odocoileus virginianus) in Cades Cove, Great Smoky Mountains National Park. Succinylcholine chloride was used as the immobilizing agent. Hematology and serum biochemistry assays were performed on samples. Additional data collected from animals included physical measurements, weights, and ages. One-way analysis of variance was used to identify differences in blood parameters as functions of year of collection (1980 through February 1981; December 1981 through 1982), season of collection (May through October; November through April), sex, and age (<1.5 years; ≥1.5 years). Physical parameters were analyzed to determine differences among three groups based on sex and age: juvenile males and females (<1.5 years), adult females (≥1.5 years), and adult males (≥1.5 years).

A normochromic, macrocytic anemia, with high mean corpuscular volume and mean corpuscular hemoglobin values and low erythrocyte counts, existed for all analysis groups except for samples collected during 1981-1982. Total leukocyte counts were consistently high throughout the study period with mean values ranging from 3956-6878 leukocytes/µl. Differential leukocyte counts revealed elevated levels of eosinophils, basophils, and monocytes throughout the study period, as well as neutrophils with toxic granulation in 25% of the blood smears examined. These hematology results are indicative of a response to a variety of conditions including generalized or localized infections, hemorrhage, tissue necrosis, or parasitism.

Several serum biochemistry parameters differed between seasons of collection. Fewer differences were noted based on year of collection, sex, or age. Values for certain parameters known to reflect nutritional status (blood urea nitrogen, uric acid, calcium, cholesterol) were lower (P<0.001) in animals sampled during November through April, indicating seasonal dietary differences. Overall, the data suggest that the Cades Cove deer were wel1-nourished during the study period.

Measurements of parameters known to be indicators of stress and excitability (glucose, lactate dehydrogenase, creatinine phosphokinase, aspartate aminotransferase) suggest that, in general, deer were not overly stressed during capture and handling.

Variations of serum iron between years (P<0.05) and between seasons (P<0.001) can be explained in relation to the apparent normochromic, macrocytic anemia.

Although few juveniles were sampled (n=9), differences between the age groups, with higher values for younger animals, were noted for phosphorus, alkaline phosphatase (P<0.001), calcium, lactate dehydrogenase, and alanine aminotransferase (P<0.05).

Physical measurements showed that males were significantly larger than females, both of which were generally larger than juveniles. No differences were noted for the time required for succinyIcholine chloride to take effect, though the data indicate that juveniles were consistently overdosed due to miscalculation of body size and weight.

Variations of certain parameters observed in this study are known to be indicators of pathologic conditions. More specific analyses are needed to determine the cause or causes of variation. In addition, it is recommended that future management of the Cades Cove deer herd include analysis of parameters identified by this study to be the most useful for assessing conditional status, particularly hematology assays and total differential leukocyte counts.