Balastegui Martínez, María Teresa

Loss of adipose tissue in vertebrate wildlife species is indicative of decreased nutritional and health status and is linked to environmental stress and diseases. Body condition indices (BCI) are commonly used in ecological studies to estimate adipose tissue mass across wildlife populations. However, these indices have poor predictive power, which poses the need for quantitative methods for improved population assessments. Here, we calibrate bioelectrical impedance spectroscopy (BIS) as an alternative approach for assessing the nutritional status of vertebrate wildlife in ecological studies. BIS is a portable technology that can estimate body composition from measurements of body impedance and is widely used in humans. BIS is a predictive technique that requires calibration using a reference body composition method. Using sea turtles as model organisms, we propose a calibration protocol using computed tomography (CT) scans, with the prediction equation being: adipose tissue mass (kg) = body mass − (−0.03 [intercept] − 0.29 * length2/resistance at 50 kHz + 1.07 * body mass − 0.11 * time after capture). CT imaging allows for the quantification of body fat. However, processing the images manually is prohibitive due to the extensive time requirement. Using a form of artificial intelligence (AI), we trained a computer model to identify and quantify nonadipose tissue from the CT images, and adipose tissue was determined by the difference in body mass. This process enabled estimating adipose tissue mass from bioelectrical impedance measurements. The predictive performance of the model was built on 2/3 samples and tested against 1/3 samples. Prediction of adipose tissue percentage had greater accuracy when including impedance parameters (mean bias = 0.11%–0.61%) as predictor variables, compared with using body mass alone (mean bias = 6.35%). Our standardized BIS protocol improves on conventional body composition assessment methods (e.g., BCI) by quantifying adipose tissue mass. The protocol can be applied to other species for the validation of BIS and to provide robust information on the nutritional and health status of wildlife, which, in turn, can be used to inform conservation decisions at the management level.

GI obstruction often leads to intractable vomiting, the consequences of which can be life-threatening. For diagnosing, an ileus clinical examination with abdominal radiographs or ultrasonographs are chosen routinely. The purpose of the study was to determine the incidence of GI obstruction among animals with gastrointestinal symptoms and to define ultrasonographic accuracy in detecting these GI obstructions. 38 animals (31 dogs and 7 cats) were included in the study. At the first consultation they presented gastrointestinal symptoms. A clinical examination with palpation of the abdomen was made. An ultrasound examination was made by an experienced radiologist. 17 of the 38 animals were diagnosed with obstructive ileus. In 15 of these 17 the ileus was confirmed, and in the remaining 2 only functional obstruction and enteritis was found. For the other 21 of the 38 animals the ileus was excluded. The animals with GI obstruction accounted for 39.5% of all animals with GI symptoms. The ultrasound examination was effective in 88.2% of cases. Intestinal obstruction is common in patients with gastrointestinal symptoms. Vomiting, diarrhoea and constipation are the main symptoms. Abdomen pain is rare. Ultrasound is a valuable and safe method for detecting GI obstructions. In only 2 animals was ileus misdiagnosed.