Prevalence of dysphoria after fentanyl in dogs undergoing stifle surgery.

OBJECTIVE: To describe the prevalence of dysphoria after intraoperative administration of fentanyl by infusion and identify other risk factors influencing this in dogs undergoing stifle surgery. STUDY DESIGN: Prospective, randomized clinical study. ANIMALS: Dogs (n = 92) that had tibial plateau leveling osteotomy (TPLO) or tibial tuberosity advancement (TTA). METHODS: Dogs were anesthetized using a standardized anesthetic protocol, and randomly assigned to receive a loading dose followed by 1 of 3 infusions of fentanyl perioperatively: 2 µg/kg/h, 10 µg/kg/h, or 20 µg/kg/h. Dog characteristics and all additional medications were recorded and included as part of the statistical analysis. Dog behavior was scored before anesthesia and during recovery using a scale of 1-4 (Appendices A and B). If no improvement in behavior was seen in 3-5 minutes postextubation, dogs with a score of 3 or 4 during recovery were administered fentanyl (2 µg/kg intravenously [IV]) in the event that the behaviors associated with the higher scores were related to pain. If they did not respond favorably to the administration of additional fentanyl and wound palpation did not elicit a response, but the untoward behaviors continued, dogs were administered either a tranquilizer, sedative, or opioid antagonist, and were considered dysphoric. RESULTS: Of 92 dogs, 22 (23.9%) were considered dysphoric using aforementioned criteria. CONCLUSIONS: About one-fourth of dogs enrolled in this study were dysphoric based on study criteria.

Survival after surgery for tracheal collapse and the effect of intrathoracic collapse on survival.

OBJECTIVES: To determine (1) long-term survival of dogs with tracheal collapse (TC) receiving cervical extraluminal prosthetic rings (ELR) and (2) whether intrathoracic collapse effects long-term survival of dogs receiving ELR. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 33) with TC that had ELR. METHODS: Medical records (July 2002-July 2008) were searched for TC dogs treated with ELR. Age, breed, gender, location of TC, and age at follow-up (death or censor) were recorded. Kaplan-Meier survival curves were generated. RESULTS: Of 114 TC dogs, 33 had ELR. Breeds and gender were consistent with previous reports; mean (±SD) age at presentation was 6.3±2.6 years. TC was categorized as cervical or cervical and intrathoracic. All dogs had cervical TC and 15 had concurrent intrathoracic collapse; 8 of these had collapse of mainstem bronchi. Median survival time was >2500 days (median not reached) for cervical TC alone and 1500 days for cervical and intrathoracic TC with no difference in median survival time between groups (P = .26). CONCLUSION: Dogs with TC have a median survival time of 1680 days (4.6 years) after ELR and no differences were seen when dogs had intrathoracic collapse. Intrathoracic collapse does not exclude a dog from receiving ELR.