D. Mcfarlane et al., HEMATOLOGIC AND SERUM BIOCHEMICAL VARIABLES AND PLASMA CORTICOTROPIN CONCENTRATION IN HEALTHY AGED HORSES, American journal of veterinary research, 59(10), 1998, pp. 1247-1251
Objectives-To compare hematologic and serum biochemical variables and
plasma ACTH concentration between healthy horses 5 to 12 years old and
those more than 20 years old. Animals-30 healthy horses 5 to 12 years
old and 30 healthy horses more than 20 years old. Procedures-Venous b
lood was collected from all horses, and CBC and serum biochemical anal
ysis were performed for each horse. Plasma ACTH concentration was dete
rmined by radioimmunoassay. Student's paired t-test or the Mann-Whitne
y rank sum test was used to compare values between control and aged ho
rse groups. Results-Compared with values for control horses, aged hors
es had significantly higher erythrocyte mean cell volume and mean cell
hemoglobin. Aged horses also had significantly decreased total lympho
cyte count. Five aged horses had lymphocyte count that was lower than
the low reference limit as established for horses in our laboratory. D
ifferences between control and aged horses for serum biochemical or pl
asma ACTH values were not significant. Conclusion-Compared with younge
r adult horses, those more than 20 years old have some hematologic dif
ferences, but there is no apparent effect of aging on baseline plasma
ACTH concentration. Clinical Relevance-It is important to establish ag
e-matched control values for optimal interpretation of clinicopatholog
ic variables.