Laboratory profile of malnutrition in hospitalized dogs

Abstract

Malnutrition occurs when the supply of available nutrients is less than organic demand. It is an underdiagnosed problem in veterinary medicine and can result in several negative metabolic consequences, with greater morbidity and mortality. Currently, the classification of nutritional status (NS) is performed subjectively in veterinary medicine, so studies and discoveries about laboratory markers (objectives) of malnutrition are desirable. This study evaluated the correlations between several laboratory variables (practical and low-cost measurements) and the nutritional status (NS) of 246 dogs from a veterinary school hospital in southern Brazil. In this way, the laboratory profile of malnutrition in this population is evident. NS was classified by body condition score (BCS) and muscle mass score (MMS). A patient was considered to be malnourished if the BCS was less than 3 (values from 1 to 9). The laboratory variables analyzed were hemogram, cholesterol, total protein (TP), albumin, C-reactive protein (CRP), CRP/albumin ratio, total iron-binding capacity (TIBC), transferrin (TF), transferrin saturation index (TSI), and transthyretin. The means and standard deviations of the variables, correlation analyses, and comparative analyses (Kruskal-Wallis in α = 5%) were calculated. This research aimed to identify objective and practical malnutrition markers that help in the elaboration of a protocol for nutritional evaluation in diseased dogs. Low values of TF, TIBC, TP, hemogram, and TSI elevation were indicative of malnutrition. Additionally, cholesterol and albuminemia are not good markers of malnutrition in dogs with systemic diseases. For the graduation of the inflammatory state (important to differentiate inflammatory hypoproteinemia from protein malnutrition), it is more reliable to measure the CRP/albumin ratio. Canine transthyretin cannot be measured with reagents designed for humans, such as those used in this study. It was possible to conclude that laboratory indicators of malnutrition in sick dogs include low values of TF, TIBC, and TP, anemia, and elevations of TSI. The joint changes in these markers gradually reinforced the diagnosis.