The aim of this study was to determine the efficacy of a concentrated combination of tiletamine-zolazepam [TZ, 0.53 mg/kg body weight (BW)], ketamine (Ket, 0.53 mg/kg BW), and detomidine (Det, 0.04 mg/kg BW) in the immobilization of free-range cattle for clinical procedures. The combination was administered intramuscularly to 53 animals. Anesthesia was reversed with the α2-adrenoceptor antagonist atipamezole. Locoregional anesthesia was provided with lidocaine when required. The TZKD combination induced suitable immobilization for minor surgical procedures or medical treatments. Anesthetic onset was rapid, taking a mean of 6.1 min [standard deviation (SD) 2.8 min]. The duration of anesthesia depended on the time of administration of the antagonist; the animals recovered in the standing position in 12.9 ± 8.9 min after the administration of atipamezole. The quality of anesthesia and analgesia were satisfactory. In conclusion, this TZKD combination can be used for both immobilization and minor surgical procedures in free-range cattle.

Objective—To evaluate the ability of atropine sulfate, butylscopolammonium bromide combined with metamizole sodium, and flunixin meglumine to ameliorate the clinical adverse effects of imidocarb dipropionate in horses. Animals—28 horses with piroplasmosis. Procedures—28 horses were randomly assigned to 4 equal groups according to the pretreatment administered. Fifteen minutes before administration of 2.4 mg of imidocarb dipropionate/kg IM, horses in the first group were pretreated with 0.02 mg of atropine sulfate/kg IV, the second group with a combination of 0.2 mg of butylscopolammonium bromide/kg IV and 25 mg of metamizole sodium/kg IV, the third group with 1.1 mg of flunixin meglumine/kg IV, and the fourth (control) group with 1 mL of saline (0.9% NaCl) solution/50 kg IV. Physical examination, including evaluation of rectal temperature, heart and respiratory rates, capillary refill time, mucous membrane color, hydration status, abdominal sounds, signs of abdominal pain, salivation, diarrhea, and number of defecations, was performed. Results—Imidocarb dipropionate use in the control group was associated with serious adverse effects including signs of abdominal pain (4/7 horses) and diarrhea (2/7). Horses pretreated with atropine had no diarrhea, but 6 had signs of abdominal pain. Only 1 horse that received butylscopolammonium-metamizole pretreatment had signs of abdominal pain and 3 had diarrhea, which was numerically but not significantly different than the control group. Of horses pretreated with flunixin, 3 had signs of abdominal pain and 3 had diarrhea. Conclusions and Clinical Relevance—A combination of butylscopolammonium bromide and metamizole sodium may be useful to ameliorate the adverse effects of imidocarb dipropionate in horses, although group size was small and significant differences from the control group were not found.

Objective—To assess biometric tools for gait analysis in healthy calves by use of pressure mat sensors, a handheld algometer, and serial circumferential measurements of selected joints. Animals—20 six- to eight-week-old healthy male Holstein calves. Procedures—Calves were evaluated over a 4-day period. Gait analysis was performed by training calves to walk over a pressure-sensitive mat, which recorded quantitative measurements. An algometer was applied perpendicular to each joint until an aversion response was observed or a preset limit of 50 N/cm2 was obtained. Circumference measurements of the carpal and tarsal joints were obtained by the application of a flexible measuring tape to defined areas of each limb. Variability between joint circumference measurements and pressure mat variables were analyzed with a standard least squares means model. Algometer measurements were dichotomized, and logistic regression was used to assess the probability that a calf reacted to algometer-applied pressure. Results—1 calf was removed from the study because of lameness. Mean carpal and tarsal joint circumference measurements were reliable and consistent among calves. Algometry results suggested that healthy calves were more sensitive to pressure applied to the elbow and stifle joints, compared with pressure applied to the carpal, tarsal, and metacarpophalangeal or metatarsophalangeal joints. Pressure mat variables of stance time and stride velocity varied greatly among calves, whereas impulse and maximum forces varied little. Conclusions and Clinical Relevance—Findings can serve as reference points for other studies and be used for comparison with results for calves with lameness or altered gaits.

Objective-To determine whether oxidative stress could be induced in canine chondrocytes in vitro. Sample-Chondrocytes obtained from healthy adult mixed-breed dogs. Procedures-Harvested chondrocytes were maintained at 37°C with 5% CO2 for 24 hours. To assess induction of oxidative stress, 2 stimuli were used: hydrogen peroxide and a combination of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). To determine the effect of hydrogen peroxide, a set of chondrocyte-seeded plates was incubated with control medium alone or hydrogen peroxide (100, 200, or 300μM) for 24 hours. For inhibition of oxidative stress, cells were incubated for 24 hours with N-acetylcysteine (NAC; 10mM) before exposure to hydrogen peroxide. Another set of chondrocyte-seeded plates was incubated with control medium alone or with IL-1β (10 ng/mL) and TNF-α (1 ng/mL) for 24 hours. Supernatants were obtained for measurement of prostaglandin E2 production, and cell lysates were used for measurement of superoxide dismutase (SOD) activity and reduced-glutathione (GSH) concentration. Results-Chondrocytes responded to the oxidative stressor hydrogen peroxide with a decrease in SOD activity and GSH concentration. Exposure to the antioxidant NAC caused an increase in SOD activity in hydrogen peroxide-stressed chondrocytes to a degree comparable with that in chondrocytes not exposed to hydrogen peroxide. Similarly, NAC exposure induced significant increases in GSH concentration. Activation with IL-1β and TNF-α also led to a decrease in SOD activity and increase in prostaglandin E2 production. Conclusions and Clinical Relevance-Canine chondrocytes responded to the oxidative stress caused by exposure to hydrogen peroxide and cytokines. Exposure to oxidative stress inducers could result in perturbation of chondrocyte and cartilage homeostasis and could contribute to the pathophysiology of osteoarthritis. Use of antioxidants, on the other hand, may be helpful in the treatment of arthritic dogs.

Objective-To determine the pharmacokinetics of tramadol hydrochloride (30 mg/kg) following twice-daily oral administration in Hispaniolan Amazon parrots (Amazona ventralis). Animals-9 healthy adult Hispaniolan Amazon parrots. Procedures-Tramadol hydrochloride was administered to each parrot at a dosage of 30 mg/kg, PO, every 12 hours for 5 days. Blood samples were collected just prior to dose 2 on the first day of administration (day 1) and 5 minutes before and 10, 20, 30, 60, 90, 180, 360, and 720 minutes after the morning dose was given on day 5. Plasma was harvested from blood samples and analyzed by high-performance liquid chromatography. Degree of sedation was evaluated in each parrot throughout the study. Results-No changes in the parrots’ behavior were observed. Twelve hours after the first dose was administered, mean +/- SD concentrations of tramadol and its only active metabolite M1 (O-desmethyltramadol) were 53 +/- 57 ng/mL and 6 +/- 6 ng/mL, respectively. At steady state following 4.5 days of twice-daily administration, the mean half-lives for plasma tramadol and M1 concentrations were 2.92 +/- 0.78 hours and 2.14 +/- 0.07 hours, respectively. On day 5 of tramadol administration, plasma concentrations remained in the therapeutic range for approximately 6 hours. Other tramadol metabolites (M2, M4, and M5) were also present. Conclusions and Clinical Relevance-On the basis of these results and modeling of the data, tramadol at a dosage of 30 mg/kg, PO, will likely need to be administered every 6 to 8 hours to maintain therapeutic plasma concentrations in Hispaniolan Amazon parrots.

Objective-To test the hypothesis that inflammatory responses to endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS). Animals-6 healthy horses and 6 horses with EMS. Procedures-Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline data were obtained 30 minutes before each infusion. After infusion, a physical examination was performed hourly for 9 hours and at 15 and 21 hours; a whole blood sample was collected at 30, 60, 90, 120, 180, and 240 minutes for assessment of inflammatory cytokine gene expression. Liver biopsy was performed between 240 and 360 minutes after infusion. Results-Following lipopolysaccharide infusion in healthy horses and horses with EMS, mean rectal temperature, heart rate, and respiratory rate increased, compared with baseline findings, as did whole blood gene expression of interleukin (IL)-1β, IL-6, IL-8, IL-10, and tumor necrosis factor-α. The magnitude of blood cytokine responses did not differ between groups, but increased expression of IL-6, IL-8, IL-10, and tumor necrosis factor-α persisted for longer periods in EMS-affected horses. Lipopolysaccharide infusion increased liver tissue gene expressions of IL-6 in healthy horses and IL-8 in both healthy and EMS-affected horses, but these gene expressions did not differ between groups. Conclusions and Clinical Relevance-Results supported the hypothesis that EMS affects horses’ inflammatory responses to endotoxin by prolonging cytokine expression in circulating leukocytes. These findings are relevant to the association between obesity and laminitis in horses with EMS.

Objective-To test the hypothesis that glucose and insulin dynamics during endotoxemia differ between healthy horses and horses with equine metabolic syndrome (EMS). Animals-6 healthy adult mares and 6 horses with EMS. Procedures-Each horse randomly received an IV infusion of lipopolysaccharide (20 ng/kg [in 60 mL of sterile saline {0.9% NaCl} solution]) or saline solution, followed by the other treatment after a 7-day washout period. Baseline insulin-modified frequently sampled IV glucose tolerance tests were performed 27 hours before and then repeated at 0.5 and 21 hours after infusion. Results were assessed via minimal model analysis and area under the curve values for plasma glucose and serum insulin concentrations. Results-Lipopolysaccharide infusion decreased insulin sensitivity and increased area under the serum insulin concentration curve (treatment × time) in both healthy and EMS-affected horses, compared with findings following saline solution administration. The magnitude of increase in area under the plasma glucose curve following LPS administration was greater for the EMS-affected horses than it was for the healthy horses. Horses with EMS that received LPS or saline solution infusions had decreased insulin sensitivity over time. Conclusions and Clinical Relevance-Glucose and insulin responses to endotoxemia differed between healthy horses and horses with EMS, with greater loss of glycemic control in EMS-affected horses. Horses with EMS also had greater derangements in glucose and insulin homeostasis that were potentially stress induced. It may therefore be helpful to avoid exposure of these horses to stressful situations.

Objective—To determine an efficient method for the collection of semen samples by means of electroejaculation, characterize spermatozoa quality and quantity, and determine the effect of refrigerated storage on motility of spermatozoa obtained from green iguanas (Iguana iguana). Animals—18 adult green iguanas. Procedures—Green iguanas were anesthetized, and semen samples were obtained by means of electroejaculation. Up to 3 series of electrostimulations were performed; the procedure was stopped after a semen sample was obtained. Various semen sample variables were evaluated. Results—Semen samples were obtained from 16 iguanas; most (n = 10) iguanas produced a semen sample after the second series of electrostimulations. Median semen sample volume was 0.05 mL. Mean spermatozoa concentration was 2 69.0 × 10(6) spermatozoa/mL. Median percentage of motile spermatozoa was 78%. The only morphological abnormality of spermatozoa was bent tails (mean percentage in a semen sample, 5.7%). Spermatozoa motility decreased significantly during refrigeration (4°C); median percentage motility after 24, 48, and 72 hours of refrigeration was 60%, 33%, and 0%, respectively. Conclusions and Clinical Relevance—Results of this study suggested electroejaculation can be performed to collect semen samples from green iguanas, characteristics of iguana semen samples are similar to those for semen samples obtained from other reptiles, and motility of iguana spermatozoa decreases during refrigeration within 48 to 72 hours.

Abundant lymphocyte infiltration is frequently found in canine malignant mammary tumors, but the pathological features and immunophenotypes associated with the infiltration remain to be elucidated. The aim of the present study was to evaluate the relationship between lymphocyte infiltration, histopathological features, and molecular phenotype in canine mammary carcinoma (MC). The study was done with archived formalin-fixed, paraffin-embedded samples (n = 47) by histologic and immunohistochemical methods. The degree of lymphocyte infiltration was evaluated by morphologic analysis, and the T- and B-cell populations as well as the T/B-cell ratio were evaluated by morphometric analysis; results were compared with the histologic features and molecular phenotypes. The degree of lymphocyte infiltration was significantly higher in MCs with lymphatic invasion than in those without lymphatic invasion (P < 0.0001) and in tumors of high histologic grade compared with those of lower histologic grade (P = 0.045). Morphometric analysis showed a larger amount of T-cells and B-cells in MCs with a higher histologic grade and lymphatic invasion, but the T/B ratio did not change. Lymphocyte infiltration was not associated with histologic type or molecular phenotype, as assessed from the immunohistochemical expression of epidermal growth factor receptor 2, estrogen receptor, cytokeratin 14, and p63. Since intense lymphocyte infiltration was associated with aggressive histologic features, lymphocytes may be important for tumor aggressiveness and greater malignant behavior in the tumor microenvironment.

Objective—To determine the effects of advanced age on whole-body protein synthesis and activation of the mechanistic target of rapamycin (mTOR) signaling pathway in skeletal muscle of horses Animals—Six 22- to 26-year-old (aged) and six 7- to 14-year-old (mature) horses. Procedures—Whole-body protein synthesis was measured with a 2-hour primed constant infusion of 13C sodium bicarbonate, followed by a 4-hour primed constant infusion of 1-13C phenylalanine. After the infusions, a biopsy specimen was obtained from a gluteus medius muscle and activation of protein kinase B (Akt), p70 riboprotein S6 kinase (S6K1), riboprotein S6 (rpS6), and eukaryotic initiation factor 4E binding protein 1 (4EBP1) was determined with western immunoblot analysis. For all horses, inflammatory cytokine expression in muscle and blood samples was measured with quantitative real-time PCR analysis. Results—Advanced age had no effect on whole-body protein synthesis or the phosphorylation of Akt, rpS6, and 4EBP1; however, muscle specimens of aged horses had 42% lower phosphorylation of S6K1 than did those of mature horses. Aged and mature horses had similar inflammatory cytokine expression in muscle and blood samples. Conclusions and Clinical Relevance—The lower S6K1 activation for aged horses, compared with that for mature horses, could be indicative of low rates of muscle protein synthesis in aged horses. However, advanced age had no effect on any other indicators of whole-body or muscle protein synthesis or on measures of systemic or muscle inflammation, which suggested that protein metabolism and subsequently requirements may not differ between healthy mature and aged horses.