ABSTRACT.-Rodrigues M., Deschk M., Santos G.G.F., Perri S.H.V., Merenda V.R., Hussni C.A., Alves A.L.G. & Rodrigues C. A. 2013 The objectives of this study were to evaluate the characteristics of ruminal fluid, blood gas analysis, pedometer activity and suclinical laminitis occurrence, through the presence of secondary foot diseases in high production dairy cows, from a commercial herd. 200 Holstein cows originating from the same farm, located in Araçatuba/SP, Brazil, were divided into four groups, which are established from the daily milk production. Initially clinical examination of the cows was procedure, followed by sampling of rumen fluid, by esophageal tube. Fluid was evaluated for pH, color, odor, consistency, sedimentation, flotation and methylene blue reduction test. Venous blood samples were also collected for blood gas analysis, in addition to collecting data from pedometrics (number of steps) and daily milk production. Data were tabulated and submitted to correlation analysis. No animal had reported changes in rumen pH. Non-acid base imbalance were found, since the values of blood pH, PCO2, TCO2, HCO3-and BE were normal during hemogasimetric analysis. The pedometric was effective as a screening method to cows with foot diseases. It demonstrated reduction in the number of steps due to pain, correlated with lower milk production. However, the identification of foot lesions was only possible through specific digital clinical examination. The occurrence of 49.5 % of herd foot problems was due to the risk factors present in the farm. The abrasive concrete and inadequate facilities, also associated with the possible occurrence of sub-acute ruminal acidosis, were observed as risk factors. However, sub-acute ruminal acidosis was undiagnosed by the methods used. The correlation between the values of ruminal pH, and blood gas analysis pedometrics showed efficient for the early diagnosis of foot diseases and also in establishing the etiology of these diseases. Subclinical laminitis occurred primarily in cow's herd, considering the multifactorial etiology of this disease, occurrence and distribution of foot diseases diagnosed.INDEX TERMS: Affections podal, bovine, subclinical laminitis, rumen fluid, subacute ruminal acidosis.