There has been growing interest in the specific impacts of anthropogenic factors on the health of wildlife. This study examined hematology and serum chemistry status of a prominent carnivore, the maned wolf (Chrysocyon brachyurus), living in, on the boundaries to, or on adjacent farmlands to the Serra da Canastra National Park, Brazil. Twenty-eighty wolves were captured, and values were compared 1) between subadults (n=8 animals) and adults (n=20 animals), 2) males (n = 12 animals) and females (n = 16 animals), and 3) among wolves living inside the park (n = 11), near the park border (n = 11 animals), and in neighboring farming areas (n = 6 animals). Age, gender, and wolf locations influenced (P<0.05) hematology and serum biochemistry values. Specifically, adults had lower (P<0.05) circulating phosphorus than subadults. Males had lower (P<0.05) serum glucose, creatinine Phosphokinase, and cholesterol and higher (P<0.05) potassium than females. Erythrocyte count and serum Cholinesterase were lower (P<0.05) in wolves living within the park compared with near the park border or on farmlands. Mean corpuscular volume was lower (P<0.05) in wolves living near the park border than those ranging within the park and on farmlands. Aspartate transaminase and chloride were higher (P<0.05) in wolves living inside the park compared with those ranging near the park border. Creatinine Phosphokinase was lower (P<0.05) in wolves living on farmland compared with the other two locations. These results clearly reveal a relationship between age and gender on hematology and serum biochemistry values in free-living maned wolves. More importantly, certain traits indicative of health are potentially compromised in wolves living in areas under anthropogenic pressure. These data lay a foundation for examining the influence of farming and local domestic species on disease susceptibility and fitness in the maned wolf. © 2009 Wildlife Disease Association.