Effects of various anesthetic agents on laryngeal motion during laryngoscopy in normal dogs

OBJECTIVE: To evaluate the effects of various drugs and drug combinations conventionally used for anesthesia on arytenoid cartilage motion during laryngoscopy in normal dogs. STUDY DESIGN: Experimental study. ANIMALS: Six large breed healthy dogs with no previous history of respiratory dysfunction. METHODS: Each dog was randomly assigned to a different injectable anesthetic protocol once weekly for 6 weeks, then in the 7th week all dogs were anesthetized with isoflurane. Videolaryngoscopy was performed and recorded starting immediately after induction until dogs could no longer be safely restrained for endoscopy. Video was digitized and 3 still images of maximal inspiration and expiration from the first 15 seconds (induction) and the last 15 seconds (recovery) were captured and imported into an image analysis software program. The height and area of the laryngeal ostium were measured in pixels. Normalization of the glottal gap area was performed using the formula (normalized glottal gap area (NGGA)=area in pixels/height(2)). ANOVA was performed on the NGGA of images collected at inspiration and expiration during induction and recovery. Fischer's exact test was performed when significance (P<.05) was found. RESULTS: Within each protocol, laryngeal motion (defined as change in NGGA) at induction was not significantly different from laryngeal motion measured at recovery. Additionally, no significant differences were found in arytenoid motion immediately after induction when anesthetic protocols were compared. Arytenoid motion before recovery was significantly greater with thiopental when compared with propofol (P=.046), ketamine+diazepam (P=.0098), acepromazine+thiopental (P=.0021), and acepromazine+propofol (P=.0065). No significant difference in arytenoid motion was seen immediately after induction or before recovery when acepromazine+butorphanol+ isoflurane and thiopental were compared. CONCLUSION: We concluded that intravenous thiopental given to effect is the best choice for assessing laryngeal function in dogs. Dogs premedicated with acepromazine with or without opioids that require further anesthetic restraint for laryngoscopy should be anesthetized with isoflurane administered by mask. CLINICAL RELEVANCE: Misdiagnosis of laryngeal paralysis during laryngoscopy can be avoided by selecting the anesthetic regimens with the least effect on arytenoid motion.     

Cecal colonization of chicks by porcine strains of Campylobacter coli

Ten genotypically distinct strains of Campylobacter coli were isolated from a swine production facility. These porcine isolates were then orally inoculated into day-of-hatch leghorn chicks and were excellent colonizers of the chick cecum. Campylobacter coli recovered from inoculated chickens were genotypically identical to the challenge strain. The absence of host specificity suggests a possible movement of strains among swine, field animals and birds, and poultry houses.     

Prognostic factors and survival after radiotherapy for intranasal neoplasms in dogs: 70 cases (1974-1985)

Survival time and 31 prognostic factors were analyzed for 70 dogs undergoing radiotherapy for intranasal tumors at the Veterinary Hospital of the University of Pennsylvania between 1974 and 1985. At the time of analysis (January 1987), 14.3% (10 of 70) of the dogs were alive. Of the remaining dogs, 34 died because of tumor recurrence, 14 died because of intercurrent disease, and 12 were lost to follow-up evaluation. Pretreatment prognostic factors that were significantly correlated with disease-free interval or long-term survival could not be identified. Notably, presence of a facial mass was not prognostically significant, suggesting that extensive disease should not preclude treatment. Median survival time of dogs with all tumor types was 16.5 months, with a 1-, 2-, and 3-year survival of 54%, 43%, and 35%, respectively. Median survival time of dogs with carcinoma was 13.5 months, with 1-year survival of 51%, 2-year survival of 37%, and 3-year survival of 31%. Orthovoltage radiation was efficacious in the treatment of canine intranasal tumors.     

Immunotoxicity of ochratoxin A to growing gilts.

Ochratoxin A (OA) was incorporated in the diets of growing gilts (mean body weight, 20.1 kg) at a concentration of 2.5 mg of OA/kg of feed and was fed continuously for 35 days. Humoral and cell-mediated immunologic measurements were evaluated to determine the effects of OA on immune function in swine. Cutaneous basophil hypersensitivity to phytohemagglutinin (PHA), delayed hypersensitivity to tuberculin, PHA-induced lymphocyte blastogenesis, interleukin-2 production, total and isotype immunoglobulin concentrations, antibody response to chicken RBC, and macrophage activation were used to evaluate immune function. Gilts treated with OA had reduced cutaneous basophil hypersensitivity response to PHA, reduced delayed hypersensitivity to tuberculin, decreased stimulation index for lymphoblastogenesis, decreased interleukin-2 production when lymphocytes were stimulated with concanavalin A, and decreased number and phagocytic activity of macrophages. Differences were not observed for total and isotype immunoglobulin concentrations, or humoral hemagglutination (chicken RBC) titer. These data indicate that OA may suppress cell-mediated immune response in growing swine.