Assessment of brachial plexus blockade in chickens by an axillary approach

ObjectiveTo assess the brachial plexus block in chickens by an axillary approach and using a peripheral nerve stimulator.Study designProspective, randomized, double-blinded study.AnimalsSix, 84-week old, female chickens.MethodsMidazolam (1 mg kg⁻¹) and butorphanol (1 mg kg⁻¹) were administered into the pectoralis muscle. Fifteen minutes later, the birds were positioned in lateral recumbency and following palpation of the anatomic landmarks, a catheter was inserted using an axillary approach to the brachial plexus. Lidocaine or bupivacaine (1 mL kg⁻¹) was injected after plexus localization by the nerve stimulator. Sensory function was tested before and after blockade (carpus, radius/ulna, humerus and pectoralis muscle) in the blocked and unblocked wings. The latency to onset of motor and sensory block and the duration of sensory block were recorded. A Friedman nonparametric one-way repeated-measures anova was used to compare scores from baseline values over time and to compare the differences between wings at each time point.ResultsA total of 18 blocks were performed with a success rate of 66.6% (12/18). The latency for motor block was 2.8 ± 1.1 and 3.2 ± 0.4 minutes for lidocaine and bupivacaine, respectively. The latencies for and durations of the sensory block were 6.0 ± 2.5 and 64.0 ± 18.0 and 7.8 ± 5.8 and 91.6 ± 61.7 minutes for lidocaine and bupivacaine, respectively. There was no statistical difference between these times for lidocaine or bupivacaine. Sensory function was not abolished in nonblocked wings.Conclusions and clinical relevanceThe brachial plexus block was an easy technique to perform but had a high failure rate. It might be useful for providing anesthesia or postoperative analgesia of the wing in chickens and exotic avian species that have similar wing anatomy.     

Effects of remifentanil infusion regimens on cardiovascular function and responses to noxious stimulation in propofol-anesthetized cats

OBJECTIVE: To evaluate the effects of 2 remifentanil infusion regimens on cardiovascular function and responses to nociceptive stimulation in propofol-anesthetized cats. ANIMALS: 8 adult cats. PROCEDURES: On 2 occasions, cats received acepromazine followed by propofol (6 mg/kg then 0.3 mg/kg/min, i.v.) and a constant rate infusion (CRI) of remifentanil (0.2 or 0.3 microg/kg/ min, i.v.) for 90 minutes and underwent mechanical ventilation (phase I). After recording physiologic variables, an electrical stimulus (50 V; 50 Hz; 10 milliseconds) was applied to a forelimb to assess motor responses to nociceptive stimulation. After an interval (> or = 10 days), the same cats were anesthetized via administration of acepromazine and a similar infusion regimen of propofol; the remifentanil infusion rate adjustments that were required to inhibit cardiovascular responses to ovariohysterectomy were recorded (phase II). RESULTS: In phase I, heart rate and arterial pressure did not differ between remifentanil-treated groups. From 30 to 90 minutes, cats receiving 0.3 microg of remifentanil/kg/min had no response to noxious stimulation. Purposeful movement was detected more frequently in cats receiving 0.2 microg of remifentanil/kg/min. In phase II, the highest dosage (mean +/- SEM) of remifentanil that prevented cardiovascular responses was 0.23 +/- 0.01 microg/kg/min. For all experiments, mean time from infusion cessation until standing ranged from 115 to 140 minutes. CONCLUSIONS AND CLINICAL RELEVANCE: Although the lower infusion rate of remifentanil allowed ovariohysterectomy to be performed, a CRI of 0.3 microg/kg/min was necessary to prevent motor response to electrical stimulation in propofol-anesthetized cats. Recovery from anesthesia was prolonged with this technique.     

The attenuated sopB mutant of Salmonella enterica serovar Typhimurium has the same tissue distribution and host chemokine response as the wild type in bovine Peyer's patches

Salmonella enterica serovar Typhimurium is an important cause of enteric infections in farm animals and it is one of the most frequent food borne infections worldwide. Serovar Typhimurium lacking the sopB gene is attenuated for induction of host inflammatory response and fluid accumulation into the intestinal lumen, which correlates with clinical diarrhea. SopB is an inositol phosphate phosphatase, but its exact role in the pathogenesis of salmonellosis is still unclear. We employed the bovine ileal ligated loop model to compare the tissue distribution of a sopB mutant and its wild type parent serovar Typhimurium. Sections of the Peyer's patches were histologically processed and immuno-stained for detection of serovar Typhimurium. In addition, samples were processed for transmission electron microscopy, and the profile of expression of host chemokine and cytokine responses was assessed. Ultrastructurally both strains had the same ability to invade intestinal epithelial cells. No differences were detected in the tissue distribution of the sopB mutant and the wild type organism and both strains elicited the same profile of chemokines and pro-inflammatory cytokines. In conclusion, our results indicate that the attenuation of the sopB mutant is associated with pathogenic mechanisms other than invasion and distribution in host intestinal tissues.     

Genetic characterization of porcine circovirus type 2 in captive wild boars in southern Brazil

Tropical Animal Health and Production - Porcine circovirus type 2 (PCV2) has been identified in pig population in Brazil since 2000, but scarce studies involving wild boars with PCV2 infection are...     

Influence of amount and frequency of protein supplementation to steers consuming low-quality,cool-season forage: intake,nutrient digestibility,and ruminal fermentation

This experiment evaluated the influence of protein supplementation frequency (SF) and amount offered on intake, nutrient digestibility, and ruminal fermentation by rumen-fistulated beef steers consuming low-quality [2.9% crude protein (CP); dry matter (DM) basis], cool-season forage. Seven Angus × Hereford steers (300 ± 27 kg) fitted with ruminal cannulas were randomly assigned to 1 of 7 treatments in an incomplete 7 × 4 Latin square. Treatments, in a 2 × 3 factorial design plus a non-supplemented control (CON), consisted of 2 levels of supplemental soybean meal, 100% (F) or 50% (H) of the estimated rumen-degradable protein requirement, provided daily (D), once every 5 d (5D), or once every 10 d (10D). Experimental periods were 30 d and dry matter intake (DMI) was measured from days 19 to 28. On days 21 (all supplements provided) and 30 (only daily supplements provided; day immediately prior to supplementation for 5D and 10D treatments) ruminal fluid was collected for ruminal pH, ammonia-N (NH₃), volatile fatty acids (VFA), and determination of ruminal fermentation variables. Forage and total DM, organic matter (OM), and nitrogen (N) intake increased with supplementation (P ≤ 0.04). However, a linear effect of SF × amount of supplement interaction was observed for forage and total DM, OM, and N intake (P ≤ 0.04), with each variable decreasing as SF decreased, but the decrease being greater with F vs. H. Apparent total tract DM, OM, and neutral detergent fiber digestibility was not affected by supplementation or amount of supplement provided (P ≥ 0.10). In contrast, N digestibility increased with supplementation and for F vs. H (P < 0.01). Digestibility of DM, OM, and N increased linearly as SF decreased (P ≤ 0.03). When all supplements were provided, ruminal NH₃, total VFA, and molar proportions of all individual VFA increased with supplementation (P ≤ 0.04), whereas acetate:propionate ratio decreased (P < 0.01). When only daily supplements were provided, none of the aforementioned fermentation parameters were affected (P ≥ 0.09). In summary, reducing the amount of supplemental CP provided to ruminants consuming low-quality forages, when supplementation intervals are >5 d, can be a management tool to maintain acceptable levels of DMI, nutrient digestibility, and ruminal fermentation while reducing supplementation cost.     

Assessment of dexmedetomidine/ketamine anesthesia in golden-headed lion tamarins (Leontopithecus chrysomelas)

OBJECTIVE: To compare the anesthetic and cardiovascular effects of dexmedetomidine/ketamine combinations in golden-headed lion tamarins. STUDY DESIGN: Prospective blinded randomized study. ANIMALS: Six healthy golden-headed lion tamarins, three males and three females were studied (mean body weight +/- SD = 0.498 +/- 0.054 kg). METHODS: The animals were given one of the dexmedetomidine/ketamine combinations (0.005/10, 0.01/10, and 0.01/5 mg kg(-1) IM; treatments 5D/10K, 10D/10K, and 10D/5K, respectively) on three successive occasions. Time to sedation and recumbency, as well as anesthesia, standing, and walking times were recorded. Heart and respiratory rate, arterial blood pressure, hemoglobin saturation, and rectal temperature were recorded during anesthesia. Sedation, muscle relaxation, and auditory response were evaluated after drug administration. RESULTS: Heart rate decreased after two combinations (10D/5K and 10D/10K). Respiratory rate and rectal temperature progressively decreased in all the treatments. Arterial blood pressures were maintained in 5D/10K and 10D/5K treatments and decreased after 10D/10K administration. There were no differences in sedation and recumbency time between the treatments, but anesthesia time was significantly longer in treatment 10D/10K (67.80 +/- 13.30 minutes) compared to treatments 10D/5K (44.54 +/- 8.25 minutes) and 5D/10K (30.60 +/- 6.80 minutes). Standing time was shorter in treatment 10D/10K (11.13 +/- 10.01 minutes) than in treatments 5D/10K (18.20 +/- 10.03 minutes) and 10D/5K (19.12 +/- 14.55 minutes), and walking time was longer in treatment 5D/10K (20.00 +/- 12.46 minutes) compared with treatments 10D/10K (16.00 +/- 3.43 minutes) and 10D/5K (12.40 +/- 5.02 minutes). Anesthetic quality was significantly better 5 and 15 minutes after treatments 10D/10K and 10D/5K than after treatment 5D/10K. Analgesia scores were higher after administration of 10D/10K than after the 5D/10K treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Dexmedetomidine/ketamine is useful for chemical immobilization of golden-headed lion tamarins, but bradycardia and hypotension warrant close monitoring.     

Orbital (retrobulbar) meningioma in a Simmental cow

A 12-year-old Simmental cow was presented with a moderately firm irregular whitish mass of approximately 5 cm in diameter, occupying the right orbit. Microscopically, a poorly differentiated neoplasm was observed. The immunohistochemical panel included cytokeratins, vimentin, epithelial membrane antigen, Factor VIII, CD34, Mart-1, Melan A, smooth muscle actin, desmin, chromogranin, neuron-specific enolase, S-100 protein, and MIB-1. The neoplasm was negative for all of them, with the exception of vimentin and S-100 protein. Transmission electron microscopy revealed abundant desmosomes. These findings support the diagnosis of orbital (retrobulbar) meningioma.     

Ileal digestibility of protein and amino acids from canola meal in weaned piglets and growing pigs

Two experiments were conducted to measure the apparent ileal digestibility coefficients (AID) of protein and amino acids from canola meal (CM) and a pelleted canola meal (PCM) and their effect on specific activity (SA) of pancreatic proteases in weaned piglets and growing pigs. In experiment one, 24 piglets weaned at 17 days and weighing 5.5 kg were used. Treatments were a reference diet with 200 g of crude protein (CP) kg^− 1 elaborated with casein (C) as the sole protein source, a diet containing C–CM and a diet containing C–PCM. These diets were obtained using the reference diet plus 100 g kg^− 1 of CM or PCM that substituted an isoproteic mixture of casein and maize starch from reference diet, so that the AID coefficients for their protein and amino acids could be calculated by difference. In experiment two, nine castrated pigs weighing 39.5 kg were used. Treatments were a reference diet with 160 g of CP kg^− 1 elaborated with casein (C) as the sole protein source, diet C–CM and diet C–PCM. These diets were obtained using the reference diet plus 300 g kg^− 1 of CM or PCM that substituted an isoproteic mixture of casein and maize starch from reference diet. In piglets, the AID coefficients for casein were highest (P < 0.05), those of PCM were intermediate, and those of CM were the lowest. In older pigs, the AID coefficients for casein were highest, and those of CM and PCM were similar (P > 0.05). The SAs of chymotrypsin, trypsin and carboxypeptidases A and B were lower in piglets than in heavier pigs. Moreover, the SAs of trypsin, chymotrypsin, and carboxypeptidase B were lower (P > 0.05) in animals fed casein. The results showed in piglets that whereas CM was less digestible, pelleted canola meal improved protein and amino acid ileal digestibility, resulting in similar AID coefficients to those of growing pigs.