Evaluation of non-steroidal anti-inflammatory drugs in the treatment of acute lameness induced by ruminal lactic acidosis ruminal in cattle

Abstract

Lameness is the third most common disease in Brazilian feedlots, and its usually linked to the occurrence of previous cases of acute rumen lactic acidosis (ARLA). Although it is still unclear how the process of ARLA triggers laminitis, it is known that this disease is characterized by the installation of an inflammatory process that causes pain signals from the peripheral soft tissue to the hoof and claudication. The nonsteroidal anti-inflammatory drugs (NSAIDs) are the drugs of choice for treating lameness, but the selectivity of these drugs the inhibition of cyclooxygenase 2 (COX-2) and the possible side effects are important point in the choice of treatment. Thus, the present study aims to evaluate the effects and side effects of three nonsteroidal anti-inflammatory drugs (flunixin meglumine, ketoprofen and meloxicam) in the treatment of acute laminitis after induction of ARLA by excess oligofructose. We will use 32 cannulated cattle submitted to adjustment period of three days receiving 1.7 g of oligofructose per kg body weight per animal per day and subsequently underwent ARLA induction by the administrations of 17g/kg of oligofructose. After induction, the animals that show lameness score e 2 will be allocated in the following treatments: CON - will receive 8 mL of saline salution; FLU - receive 2.2 mg/kg flunixin meglumine; CET - will receive 3 mg/kg ketoprofen; MEL - receive 0.5 mg/kg meloxicam. The treatments will be given intravenously. Clinical evaluation including orthopedic examination and collection of blood and rumen fluid will be performed from adaptation (T-72, T-48, T-24), before induction with oligofructose 17g/kg (T0), during the period of observation and after the treatment in the following times: T12h, T24h, T32h, T48h, T60h, T72h, T84h and T96 hours after induction of ARLA. Rumen fluid samples will be used to determine the ruminal pH, redox potential, blue methylene reduction time, L lactate and osmolarity. Blood samples will be used for blood gas analysis, blood count, determination of cortisol, substance P, L and D lactate, metalloproteinase 9, pepsinogen, renal (urea and creatinine) and liver (gamma glutamyl transferase and aspartate aminotransferase) biochemical evaluation. Will also be collected stool samples for determination of occult blood. After induction of ARLA, the animals that present packed cell volume higher than 42% will receive additional treatment in order to reverse this situation. (AU)