The close physiological relationship between the left atrium (LA) and left ventricle (LV) suggests that an index assessing both the cardiac chambers simultaneously could provide useful information about disease severity. Consequently, investigators have proposed the atrioventricular coupling index (LACi), and demonstrated its utility in predicting the likelihood of atrial fibrillation, heart failure, and other cardiovascular events in humans. No studies have been reported in veterinary medicine. Therefore, we measured the LACi in healthy dogs and dogs affected by myxomatous mitral valve disease (MMVD). Two hundred and thirty-three dogs (105 healthy dogs and 128 dogs with MMVD) were retrospectively included in the study. The LACi (LA volume/LV volume*100) at LV end-diastole (LACi-ED) and LV end-systole (LACi-ES) of each dog was measured using a monoplane Simpson’s Method of Discs from the left apical four-chamber view. In healthy dogs, LACi-ED and LACi-ES showed no relationship with bodyweight, heart rate and age (R2 < 0.03, for all variables). In MMVD dogs, LACi-ED and LACi-ES differed between ACVIM stages (P < 0.00 and P < 0.02, for all stages). The LACi-ED and LACi-ES had similar accuracy in identifying MMVD dogs with congestive heart failure (area under the curve of 0.920 and 0.906, respectively). Our data suggest that LACi can be useful in assessing left atrioventricular function in dogs with MMVD but the diagnostic accuracy in identifying dogs with congestive heart failure was not superior to left-atrial-to-aortic ratio. Prospective studies are needed to evaluate the predictive value of this new echocardiographic index in dogs affected by MMVD.

Rupture of the Achilles (common calcaneal) tendon remains one of the most demanding soft-tissue injuries in canine orthopaedic surgery, and recent large-cohort evidence confirms that no single surgical or postoperative strategy is clearly superior across all cases. This article first provides an updated, critical review of the anatomy, aetiology, diagnosis, and surgical management of Achilles tendon rupture in dogs, covering core suture patterns, biological and synthetic augmentation techniques, and postoperative immobilisation strategies, together with their respective biomechanical evidence and clinical limitations. It then presents a clinical case of chronic, complete Achilles tendon rupture in a dog, repaired using a Three-Loop Pulley suture pattern combined with a polypropylene mesh sleeve incorporated directly into the core suture passes—a “mesh-in-stitch” technique—supported by temporary transarticular external skeletal fixation. Over a follow-up period extending to 33 months postoperatively, serial clinical, ultrasonographic, and orthopaedic evaluations showed progressive structural remodelling of the tendon, stable mesh integration, and complete functional recovery without major complications. Taken together, the reviewed literature and this clinical outcome suggest that combining intraoperative mechanical reinforcement with a scaffold for tissue ingrowth may represent a viable option for reconstructing severe, chronically ruptured tendons in dogs.