No abstract

Dual energy X-ray absorptiometry (DEXA) is a reference method for assessing body composition but is seldom `accessible in veterinary settings. Computed tomography (CT) can provide similar body composition estimates and we propose that it can be used in body composition studies in animals. We compared CT and DEXA data from 73 healthy adult neutered domestic cats. Three approaches for measuring adipose tissue percentage from full-body CT scans were explored. By examining the frequency distribution of voxels by Hounsfield unit (HU) value, it is possible to calculate a fat index (Fat%) that is in close agreement with the fat percentages obtained from DEXA scans. Fat% values obtained by the best of the methods had a mean difference of 0.96% (95% confidence interval 0.33-1.59%) from the DEXA results. Fat% obtained by the other two methods were characterized by good correlation but poor agreement and in one of the methods, the difference between the values from the two modalities was proportional to their mean. By using CT, it is possible to obtain body composition estimates that are in close agreement with those available using DEXA. While the significance of individual Fat% measurements obtained from CT can be difficult to interpret and to compare between centers, CT can contribute to research studies concerned either with nutrition or with obesity-related disorders.

Therapeutic options are urgently needed for non‐alcoholic fatty liver disease (NAFLD), but development is time‐consuming and costly. In contrast, drug repurposing offers the advantages of re‐applying compounds that are already approved, thereby reducing cost. Acetylsalicylic acid (ASA) and pentoxifylline (PTX) have shown promise for treatment of NAFLD, but have not yet been tested in combination. Guinea pigs were fed a high‐fat diet for 16 weeks and then continued on the diet while being treated with ASA, PTX or ASA+PTX for 8 weeks. Chow‐fed animals served as healthy controls. Guinea pigs were CT scanned before intervention start and at intervention end. Animals without steatosis (ie NAFLD) at week 16 were excluded from the data analysis. ASA and PTX alone or in combination did not improve hepatic steatosis, ballooning, inflammation or fibrosis nor did the treatments affect liver enzymes (aminotransferases and alkaline phosphatase) or circulating lipids. Liver triglyceride levels, relative liver weight and hepatic mRNA expression of monocyte chemoattractant protein 1, interleukin 8 and platelet‐derived growth factor b were nominally decreased. Thus, in the current study, treatment with ASA and PTX alone or in combination for 8 weeks did not ameliorate NASH or hepatic fibrosis in guinea pigs.

Objective The aim of this study was to evaluate the ex vivo effects of sequential cranial cruciate ligament transection (CCLx), medial meniscal release (MMR) and triple tibial osteotomy (TTO) on canine stifle stability compared with the intact state, across a wide range of joint angles. Study Design Nine right hind limb preparations were instrumented to provide constant quadriceps and gastrocnemius loads in a 3:1 ratio, and extended from full flexion during fluoroscopic recording. Recordings were repeated after each of CCLx, MMR and TTO. Fluoroscopic landmarks were used to calculate tibial subluxation and patellar ligament angle. Results Medial meniscal release resulted in additional cranial tibial subluxation compared with CCLx. Triple tibial osteotomy restored stifle stability up to a joint angle of 125 degrees. The presence of the crossover angle could be inferred from the patellar ligament angle and subluxation curves. Conclusion Our results suggest that in the cranial cruciate ligament-deficient stifle, the crossover angle at which loading shifts between the caudal and cranial cruciate ligaments is dependent on both loading and integrity of the medial meniscus. Triple tibial osteotomy improves stifle stability over a wide range of joint angles under a quadricep to gastrocnemius loading ratio of 3:1 by converting cranial tibial thrust to caudal tibial thrust, due to TTO increasing the amount of joint extension required to reach the crossover angle.

Based on our observations, use of ultrasound for evaluation of the femoral trochlea remains a largely qualitative assessment. A simpler and more direct objective measure of femoral trochlear adequacy is required for intra-operative use.