Classification of udder edema in cattle: systematic review / Classificação do edema de úbere em bovinos: revisão sistemática

Dairy activity in Brazil is in a process of intensification due to the low rates of financial profitability of the production systems. The search for increased profitability makes producers and technicians use management strategies that challenge animals to expose their full genetic potential. On the other hand, the increase in individual productivity can result in the occurrence of metabolic and physiological disturbances, such as udder edema. This disorder is characterized by excessive fluid accumulation in the intercellular spaces of the breast tissue and is more evident in primipara and peripartum. The disease causes discomfort, difficulty in walking, pain, a drop in food intake, and predisposes the animal to mastitis. The etiology of udder edema is not fully known, but studies show that diets rich in concentrates and high sodium and potassium intakes are predisposing factors for its occurrence. In this sense, the objective was to carry out a systematic literature review to assess and define classification standards for udder edema in dairy cows, which can be used in the field to guide the control and treatment of the disease. For the bibliographical survey, six documents were used that answered positively to the following question: Is it possible to carry out a standardized classification regarding the degrees of mammary gland edema in cattle? Difficulty was found in locating publications involving the classification of this disease, which is related to the scarcity of studies on udder edema.