PURPOSE:To measure the change in the minimum alveolar concentration of isoflurane (EtISO) associated with epidural nalbuphine and the postoperative analgesic requirements in dogs after ovariohysterectomy. METHODS:Twenty four healthy female dogs were randomly assigned to receive saline or nalbuphine at 0.3 or 0.6 mg/kg (n=8 for each group) administered via lumbosacral epidural catheter introduced cranially into the epidural canal. Changes in heart and respiratory rates and arterial blood pressure during surgery were recorded along with the corresponding EtISO. Immediately after tracheal extubation, analgesia, sedation, heart rate, respiratory rate, and arterial blood pressure were measured at predetermined intervals and every 60 min thereafter until the first rescue analgesic. RESULTS:A significant decrease in EtISO was associated with epidural nalbuphine at 0.3 mg/kg (26.3%) and 0.6 mg/kg (38.4%) but not with saline in ovariohysterectomized dogs. In the postoperative period, VAS and Colorado analgesic scores were lower for the dogs that received the higher nalbuphine dose, which only required supplemental analgesia 10 h following its administration, compared with dogs that received the lower dose. CONCLUSION:Epidural nalbuphine significantly reduces the intra-operative isoflurane requirement and provides prolonged postoperative analgesia after ovariohysterectomy in dogs.

The objective of this study was to evaluate the effectiveness of epidural methadone, tramadol or nalbuphine for postoperative analgesia in dogs. Thirty two healthy female dogs (ASA grade 1) undergoing ovariohysterectomy were randomly allocated into 4 treatments of 8 each: treatment 1 (control group) received 2% lidocaine (LD; 4 mg kgG 1), treatment 2 lidocaine and methadone (LDMT; 4 and 0.3 mg kgG 1 , respectively), treatment 3 lidocaine and tramadol (LDTR; 4 and 2 mg kgG 1 , respectively) and treatment 4 lidocaine and nalbuphine (LDNB; 4 and 0.3 mg kgG 1 , respectively). The drugs were administered into the lumbosacral space, diluted in saline solution to a total volume of 0.36 mL kgG 1. Heart and respiratory rates, arterial pressures and peripheral SpO 2 were evaluated during the peri-operative period until 240 min. Postoperative pain and sedation were measured after extubation until the first rescue analgesic and thereafter regularly for 18 h. The time to first rescue analgesia was significantly (p<0.05) prolonged in dogs in the LDMT group as compared to the control and LDTR or LDNB groups. Although all 3 drug combinations administered epidurally in dogs allowed ovariohysterectomy to be performed with sufficient analgesia, the analgesia was maintained longer with the combination of lidocaine and methadone.

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Background: Hypertrophic cardiomyopathy is the most common acquired cardiovascular disease in the feline species. A frequent complication of this cardiomyopathy is the development of cardiac congestive failure, left atrial enlargement and subsequent development of arterial thromboembolism. In a significant percentage of affected animals there is progression to congestive heart failure, resulting in cyanosis and dyspnea, often the first clinical signs reported by owners. This is a report of a 10-year-old Persian cat with hypertrophic cardiomyopathy and venous and arterial thromboembolism of non-cardiogenic origin.Case: The patient was referred for cardiac evaluation, arterial thromboembolism was the suspected cause of tetraparesis. On clinical examination, a metacarpal pulse was present in all limbs; there was no cyanosis or peripheral hypothermia thus, ruling out a thromboembolic event in the limbs. Changes consistent with feline asthma and pulmonary edema were seen on radiographs, therefore hypertrophic cardiomyopathy was suspected. Treatment with enalapril (0.25 mg/kg every 12 h) for the heart condition and prednisolone (1 mg/kg every 24 h) for asthma was started. Nine days later, the patient developed mixed dyspnea (inspiratory and expiratory) and was hospitalized with signs consistent with arterial thromboembolism: paralysis and cold extremities in the right and left pelvic limbs. The patient was euthanized due to the poor prognosis. Post mortem and histopathological findings revealed left ventricular concentric hypertrophy, with no valvular changes; disseminated intravascular coagulation, with thrombi in the arterial (iliac arteries, pancreatic and renal vessels) and venous (pulmonary and renal veins) beds; as well as multiple neoplastic lung masses, identified as scirrhous pulmonary adenocarcinoma, responsible for increased interstitial radiopacity. Metastasis was also identified at the tracheal bifurcation, causing radiographic changes similar to the alveolar pattern of pulmonary edema.Discussion: The origin of the concentric left ventricular hypertrophy was not established. Both primary hypertrophy, due to breed-related genetic predisposition or secondary hypertrophy, due to systemic hypertension from chronic kidney disease are possibilities. However, despite the left ventricular concentric hypertrophy and the presence of thrombus under the mitral valve, it was not thought that the patient had cardiogenic thromboembolism, since this would not explain the venous thrombi. The arterial and venous thromboembolism in this case were the result of paraneoplastic syndrome due to pulmonary adenocarcinoma, which was a triggering factor for disseminated intravascular coagulation and multiple thrombus formation, both in arterial and venous beds. Tumor cells may promote direct and indirect modifications in the coagulation cascade and, thus hypercoagulability. The hypercoagulatory state promoted by the tumor associated with the Virchow triad seen in feline species, explains the occurrence of thrombosis in this case report. Sensitive imaging tests, such as computed tomography or magnetic resonance imaging, may be required in middle-aged cats with hypertrophic cardiomyopathy and clinical presentations of thromboembolism or respiratory signs, in order to exclude pulmonary neoplasm as a differential diagnosis for thrombus formation and dyspnea. Furthermore, it is speculated that the antitumor effect of heparin used in the treatment for arterial thromboembolism may delay the diagnosis of lung neoplasia in cats.