Aspectos clínicos e laboratoriais de um bovino com deslocamento de abomaso à esquerda

Abstract

Background: Abomasal diseases of dairy cattle are mainly associated with stress conditions, nutritional disorders and metabolic disorders. Dairy cattle that develop left or right abomasal displacement generally lose their appetite and have 30 to 50% drop in milk production. The objective of this work is to report the clinical and laboratorial aspects of a high yielding Holstein cow suffering left abomasal displacement in Rio Grande do Sul, southern Brazil. Case: The cow was part of a research project of the Veterinary Faculty of the Federal University of Rio Grande do Sul and was monitored weekly. The animal showed decreased milk production, anorexia, prostration, tremors, diarrhea, smelly metritis and a body score of 3 in a scale of 1-5. In the clinical examination, the animal presented respiratory rate of 26 movements per minute (RV: 26-35), heart rate of 71 beats per minute (RV: 48-84), body temperature of 38.5°C (RV: 38- 39.3), normocorate mucosa, moderate dehydration and no ruminal movements. In the abdominal auscultation the animal presented metallic sound in the left flank. Blood concentration of beta-hydroxybutyrate was 8.3 mmol/L (RV: < 1.2 mmol/L). The cow underwent surgery for correction of left abomasum displacement. After surgery, the animal showed improvement of the clinical condition and ate hay, pasture and silage. Feeding with concentrate was avoided for a week. The animal had satisfactory evolution, being monitored for more 4 weeks and afterward was discharge Discussion: Genetic improvement in milk cattle has led to the selection of animals with higher milk production through the selection of animals with deeper body capacity, which may allow more space in the abdomen for abomasal movement. In the present case, clinical ketosis was confirmed through the presence of ketonuria and ketonemia. Ketosis is caused by excess ketone bodies in organic fluids, with or without clinical signs. The impact of their disorder may be related to weight loss of the animal and occurrence of secondary diseases, as abomasal displacement. The blood activity of AST, an enzyme used as an indicator of liver damage, was increase (352 U/L; RV: < 132). Elevated activity of this enzyme is related to a greater tendency to problems such as retention of placenta and hypocalcemia, among others. In the present case, the most likely is that the animal had a high body score at the time of calving, and reduced dry matter intake. After that, the cow probably initiated a hepatic lipidosis, which is common in cases of ketosis. A decrease in the production of cholesterol occurred (68 mg/dL; RV: 80-120) further aggravated by the hepatic steatosis. With ketosis the animal decreased further the dry matter intake, anad as a consequence of all of the aforementioned factors, retention of placenta and subsequent metritis may occurred, further reducing feed ingestion. Finally, all the associated problems caused the abomasum displacement worsening the condition of the animal. This clinical case confirms the importance of having good pre and postpartum management. The animal presented interrelated diseases that are frequently cause and effect for the overall picture.