BACKGROUND: Thoracoscopy is a minimally invasive method used in diagnosis and treatment of many disorders in animals, however, its application in smaller species is limited in literature which can be contributed to the challenges faced while performing a minimally invasive procedure in smaller mammals. OBJECTIVES: Evaluating the feasibility and ideal port placement considering heart as the target organ in rabbit. Also, the impact of ventilation protocol on rate of mortality was evaluated. METHODS: Twenty New Zealand white rabbits were used in this experiment. Approaches used for the introduction of the camera were Para-xiphoid and intercostal space, the optimal spot for insertion of the second trocar relative to the camera was also evaluated, lung damage and rate of mortality were assessed under two different mechanical ventilation modes of pressure-controlled and volume-controlled. RESULTS: Surgical view gained through the para-xiphoid approach is rather panoramic and spatial than the direct intercostal view, maneuver on the heart with an instrument is easier when the 5th intercostal space is used for the second trocar. With the help of PCV, lungs sustain less damage and atelectasis can be avoided till the end of the procedure and therefore, less mortality is experienced. CONCLUSIONS: Using the Para-xiphoid approach and the correct ventilation protocol provides sufficient working space under good vison, which makes the rabbit thoracoscopic heart model a practical model that can be used in many cardiac experiments.

BACKGROUND: Nowadays, due to widespread usage of anti-pain drugs, more attention is being paid to tramadol, although it has only been recognized  rather recently in veterinary medicine. Therefore, evaluation of its effects on various organs is a principal issue. OBJECTIVES: The aim of present study was to investigate cardiac function change following administration of tramadol using electrocardiography and echocardiography. METHODS: Five healthy dogs aged 3-5 years and weighting 20-26 kg were selected for study. To check the health of animals, clinical and laboratory examinations were performed. Then animals were kept for 2 weeks and vaccination and anti parasite therapy were prescribed for them. This study was conducted in 3 stages and ECG and echocardiography were recorded: before tramadol injection, immediately after injection and one hour after that. Parametric data analysis of variance with repeated measure was conducted using SPSS version 20. RESULTS: Along evaluated parameters, only left ventricular volume in end-diastole and end-systole, time interval between the Q wave to aortic valve closure, stroke volume and ejection fraction showed significant difference between the three stages. CONCLUSIONS: In conclusion, tramadol shows remarkable anti-pain effects with low cardiac side-effects in comparison to other opioid drugs. However, more studies are needed due to the importance of this subject.