Comparison of two injectable anesthetic regimes in feral cats at a large-volume spay clinic

Same‐day mass sterilization of feral cats requires rapid onset, short‐duration anesthesia. The purpose of this study was to compare our current anesthetic protocol, Telazol–ketamine–xylazine (TKX) with medetomidine–ketamine–buprenorphine (MKB). Feral female cats received either IM TKX (n = 68; 0.25 mL cat^?1; tiletamine 12.5 mg, zolazepam 12.5 mg, K 20 mg, and X 5 mg per 0.25 mL) or MKB (n = 17; M 40 µg kg^?1, K 15 mg kg^?1, and B 10 µg kg^?1). Intervals measured included time from injection to recumbency, time to surgery, duration of surgery, and time from reversal of anesthesia (TKX: yohimbine 0.50 mg cat^?1 IV; MKB: atipamezole 0.50 mg cat^?1 IM) to sternal recumbency. Following instrumentation (Vet/Ox 4403 and Vet/BP Plus 6500), physiological measurements were recorded at 5‐minute intervals, and included rectal temperature, heart rate (HR), respiratory rate (RR), SpO₂ (lingual or rectal probes), and indirect mean arterial blood pressure (MAP) (oscillometric method). Nonparametric means were compared using Mann–Whitney U‐tests. Parametric means were compared using a two‐factorial anova with Bonferroni's t‐tests. The alpha‐priori significance level was p < 0.05. Values were mean ± SD. Body weight (TKX: 2.9 ± 0.5 kg, MKB: 2.7 ± 0.7 kg), time to recumbency (TKX: 4 ± 1 minutes, MKB: 3 ± 1 minutes), time to surgery (TKX: 28 ± 7 minutes, MKB: 28 ± 5 minutes), and duration of surgery (TKX: 11 ± 7 minutes, MKB: 8 ± 5 minutes) did not differ between groups. In contrast, MKB cats required less time from reversal to sternal recumbency (TKX: 68 ± 41 minutes, MKB: 7 ± 2 minutes) and were recumbent for shorter duration (TKX: 114 ± 39 minutes, MKB: 53 ± 6 minutes). Temperature decreased during the study in both groups, but overall temperature was higher in MKB cats (38.0 ± 0.95 °C) than in TKX cats (37.5 ± 0.95 °C). RR, HR, and SpO₂ did not change during the study in either group. However, overall HR and RR were higher in TKX cats (RR: 18 ± 8 breaths minute^?1, HR: 153 ± 30 beats minute^?1) compared to MKB cats (RR: 15 ± 7 breaths minute^?1, HR: 128 ± 19 beats minute^?1). In contrast, overall SpO₂ was lower in the TKX group (90 ± 6%) compared to the MKB group (94 ± 4%). MAP was also lower in the TKX group (112 ± 29 mm Hg) compared to that in the MKB group (122 ± 20 mm Hg). However, MAP increased in the TKX group during surgery compared to pre‐surgical values, but did not change in the MKB group. The results of this study suggested that MKB might be more suitable as an anesthetic for the purpose of mass sterilization of feral female cats.     

Estimating non-genetic and genetic parameters of pre-weaning growth traits in Raini Cashmere goat

Data and pedigree information used in the present study were 3,022 records of kids obtained from the breeding station of Raini goat. The studied traits were birth weight (BW), weaning weight (WW), average daily gain from birth to weaning (ADG) and Kleiber ratio at weaning (KR). The model included the fixed effects of sex of kid, type of birth, age of dam, year of birth, month of birth, and age of kid (days) as covariate that had significant effects, and random effects direct additive genetic, maternal additive genetic, maternal permanent environmental effects and residual. (Co) variance components were estimated using univariate and multivariate analysis by WOMBAT software applying four animal models including and ignoring maternal effects. Likelihood ratio test used to determine the most appropriate models. Heritability ( \texth_\texta² ) \left( {{\text{h}}_{\text{a}}^2} \right) estimates for BW, WW, ADG, and KR according to suitable model were 0.12 ± 0.05, 0.08 ± 0.06, 0.10 ± 0.06, and 0.06 ± 0.05, respectively. Estimates of the proportion of maternal permanent environmental effect to phenotypic variance (c ²) were 0.17 ± 0.03, 0.07 ± 0.03, and 0.07 ± 0.03 for BW, WW, and ADG, respectively. Genetic correlations among traits were positive and ranged from 0.53 (BW-ADG) to 1.00 (WW-ADG, WW-KR, and ADG-KR). The maternal permanent environmental correlations between BW-WW, BW-ADG, and WW-ADG were 0.54, 0.48, and 0.99, respectively. Results indicated that maternal effects, especially maternal permanent environmental effects are an important source of variation in pre-weaning growth trait and ignoring those in the model redound incorrect genetic evaluation of kids.     

Estimates of genetic parameters for Boran, Friesian and crosses of Friesian and Jersey with the Boran cattle in the tropical highlands of Ethiopia: reproduction traits

A study with the objectives of estimating breed differences, heterosis and recombination effects as well as heritabilities (h²) and repeatabilities (r²) for age at first calving (AFC), calving interval (CI), days open (DO) and number of services per conception (SPC) was conducted using reproduction records collected from 1496 cows comprising purebred Boran (B), Friesian (F), crosses of Friesian and Jersey (J) with Boran breeds. The crossbred cow groups included four F × B crosses [1/2F:1/2B(F₁), 1/2F:1/2B(F₂), 5/8F:3/8B and 3/4F:1/4B], three J × B crosses [1/2J:1/2B(F₁), 1/2J:1/2B(F₂) and 3/4J:1/4B] and one three‐breed cross (1/4F:1/4J:1/2B). The crossbreeding parameters were estimated using a repeatability animal model for CI, DO and SPC, and a unitrait animal model for AFC. The overall least‐squares means estimated were: 38.3 ± 0.26 months, 435 ± 4 days, 145 ± 10 days and 1.58 ± 0.03 (number) for AFC, CI, DO and SPC, respectively. The breed additive effects of F and J were only significant (p < 0.01) for AFC. Relative to B, both F and J additive contributions for AFC were ?5.4 ± 0.5 and ?5.5 ± 1.9 months, respectively. Crossing the B with F and J breeds also resulted in significant heterosis (p < 0.05) ranging from 10 to 21% in all traits. The estimated recombination loss was only significant for AFC (2.8 ± 1.0 months) for F × B crosses. Heritability estimates were high for AFC (0.44 ± 0.05) and low for CI (0.08 ± 0.03), DO (0.04 ± 0.03) and SPC (0.08 ± 0.02). The corresponding estimates for the repeatability (r²) were 0.14 ± 0.02 and 0.14 ± 0.02 for CI and DO, respectively. The permanent environmental effect for SPC was zero. These findings show that breed differences between F or J and B, and the individual cow variations are low for reproductive traits studied, except for AFC. Heterotic effects seem to be the major genetic causes for the improved reproductive performances in both the F × B and J × B crossbred cows.     

Detomidine-Butorphanol-Propofol for Carotid Artery Translocation and Castration or Ovariectomy in Goats

Objective—To determine the safety and efficacy of propofol, after detomidine-butorphanol premedication, for induction and anesthetic maintenance for carotid artery translocation and castration or ovariectomy in goats. Study Design—Case series. Animals—Nine 4-month-old Spanish goats (17.1 ± 2.6 kg) were used to evaluate propofol anesthesia for carotid artery translocation and castration or ovariectomy. Methods—Goats were premedicated with detomidine (10 μg/kg intramuscularly [IM]) and butorphanol (0.1 mg/kg IM) and induced with an initial bolus of propofol (3 to 4 mg/kg intravenously [IV]). If necessary for intubation, additional propofol was given in 5-mg (IV) increments. Propofol infusion (0.3 mg/kg/min IV) was used to maintain anesthesia, and oxygen was insufflated (5 L/min). The infusion rate was adjusted to maintain an acceptable anesthetic plane as determined by movement, muscle relaxation, ocular signs, response to surgery, and cardiopulmonary responses. Systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, heart rate (HR), ECG, respiratory rate (RR), Spo₂, and rectal temperature (T) were recorded every 5 minutes postinduction; arterial blood gas samples were collected every 15 minutes. Normally distributed data are represented as mean ± SD; other data are medians (range). Results—Propofol (4.3 ± 0.9 mg/kg IV) produced smooth, rapid (15.2 ± 6 sec) sternal recumbency. Propofol infusion (0.52 ± 0.11 mg/kg/min IV) maintained anesthesia. Mean anesthesia time was 83 ± 15 minutes. Muscle relaxation was good; eye signs indicated surgical anesthesia; two goats moved before surgery began; one goat moved twice during laparotomy. Means are reported over the course of the data collection period. Means during the anesthesia for pH_a (arterial PH), P_aco₂, P_ao₂, HCO₃, and BE (base excess) ranged from 7.233 ± 0.067 to 7.319 ± 0.026, 54.1 ± 4.6 to 65.3 ± 12.0 mm Hg, 133.1 ± 45.4 to 183.8 ± 75.1 mm Hg, 26.9 ± 2.6 to 28.2 ± 2.1 mEq/L, and -0.8 ± 2.9 to 1.4 ± 2.2 mEq/L. Means over time for MAP were 53 ± 12 to 85 ± 21 mm Hg. Mean HR varied over time from 81 ± 6 to 91 ± 11 beats/minute; mean RR, from 9 ± 8 to 15 ± 5 breaths/minute; S_po₂, from 97 ± 3% to 98 ± 3%; mean T, from 36.0 ± 0.6±C to 39.1 ± 0.7±C. Over time, S_po₂ and S_ao₂ did not change significantly; HR, RR, T, and P_aco₂ decreased significantly; SAP, DAP, MAP, pH_a, P_ao₂, and BE increased significantly. HCO₃ concentrations increased significantly, peaking at 45 minutes. Recoveries were smooth and rapid; the time from the end of propofol infusion to extubation was 7.3 ± 3 minutes, to sternal was 9.2 ± 5 minutes, and to standing was 17.7 ± 4 minutes. Median number of attempts to stand was two (range of one to four). Postoperative pain was mild to moderate. Conclusions—Detomidine-butorphanol-propofol provided good anesthesia for carotid artery translocation and neutering in goats. Clinical Relevance—Detomidine-butorphanol-propofol anesthesia with oxygen insufflation may be safely used for surgical intervention in healthy goats.     

The pharmacokinetics of cefadroxil over a range of oral doses and animal ages in the foal

To evaluate the effect of foal age on the pharmacokinetics of cefadroxil, five foals were administered cefadroxil in a single intravenous dose (5 mg/kg) and a single oral dose (10 or 20 mg/kg) at ages of 0.5, 1, 2, 3 and 5 months. Pharmacokinetic parameters of terminal elimination rate constant (β_po), oral mean residence time (MRT_po), mean absorption time (MAT), rate constant for oral absorption (K_a), bioavailability F, peak serum concentrations(C_max) and time of peak concentration (t_max), were evaluated in a repeated measures analysis over dose. Across animal ages, parameters for the intravenous dose did not change significantly over animal age (P 0.05). Mean values ± SEM were: β_IV = 0.633 ± 0.038 h^?1; Cl = 0.316 ± 0.010 L/kg/h; V_c = 0.196 ± 0.008 L/kg; V_area = 0.526 ± 0.024 L/kg; V_SS =0.374 ± 0.014 L/kg; MRT_iv = 1.22 ± 0.07 h; K_el = 1.67 ± 0.08 ^h?1. Following oral administration, drug absorption became faster with age (P < 0.05), as reflected by MRT_po, MAT, K_a and t_max. However, oral bioavailability (±SE) declined significantly (P < 0.05) from 99.6 ± 3.69% at 0.5 months to 14.5 ± 1.40% at 5 months of age. To evaluate a dose effect on the pharmacokinetic parameters, a series of oral doses (5, 10, 20 and 40 mg/kg) were administered to these foals at 1 month of age. β_po (0.548 ± 0.023 h^?1) and F (68.26 ± 2.43%) were not affected significantly by the size of the dose. C_max was approximately doubled with each two-fold increase in dose: 3.15 ± 0.15, 5.84 ± 0.48, 12.17 ± 0.93 and 19.71 ± 2.19 μg/mL. Dose-dependent kinetics were observed in MRT_po, MAT, K_a and t_max.     

Growth Rates in Thoroughbred Horses Raised in Florida

SummaryGrowth rates of thoroughbred horses are not as well defined as those of other farm animals, and only a few articles summarize growth of thoroughbred horses over a prolonged period. Body weight (BW), heart girth (HG), wither height (WH), body length (BL), and hip height (HH) of 128 thoroughbred horses (59 colts and 69 fillies) were recorded from birth to 15 months of age at 14- or 28-day intervals. Data were obtained from consecutive 20 foal crops. At birth (0 day), BW was 53.55 ± 5.20 kg (range, 39.04–67.19), HG was 0.82 ± 0.03 m (range, 0.75–0.90), WH was 1.02 ± 0.03 m (range, 0.93–1.10), BL was 0.74 ± 0.03 m (range, 0.67–0.82), and HH was 1.05 ± 0.03 m (range, 0.93–1.14). At weaning (112 ± 3 days), BW was 199.57 ± 13.58 kg (range, 163.44–234.26), HG was 1.29 ± 0.04 m (range, 1.19–1.37), WH was 1.27 ± 0.03 m (range, 1.21–1.35), BL was 1.17 ± 0.03 m (range, 1.08–1.30), and HH was 1.32 ± 0.03 m (range, 1.24–1.39). At 6 months (181 ± 4 days), BW was 237.16 ± 18.48 kg (range, 186.14–288.74), HG was 1.36 ± 0.04 m (range, 1.24–1.45), WH was 1.33 ± 0.03 m (range, 1.26–1.40), BL was 1.25 ± 0.03 m (range, 1.17–1.33), and HH was 1.38 ± 0.03 m (range, 1.28–1.44). At 12 months (361 ± 8 days), BW was 337.73 ± 26.61 kg (range, 267.86–394.98), HG was 1.56 ± 0.05 m (range, 1.41–1.66), WH was 1.45 ± 0.03 m (range, 1.36–1.55), BL was 1.42 ± 0.04 m (range, 1.31–1.51), and HH was 1.49 ± 0.03 m (range, 1.41–1.57). At 15 months (447 ± 8 days), BW was 392.48 ± 30.61 kg (range, 317.80–457.18), HG was 1.64 ± 0.05 m (range, 1.52–1.76), WH was 1.49 ± 0.03 m (range, 1.42–1.58), BL was 1.48 ± 0.04 m (range, 1.40–1.59), and HH was 1.53 ± 0.03 m (range, 1.46–1.62). Two regression equations (y₁ from birth to 112 days of age and y₂ from 113 to 450 days of age) were calculated. WT_kg is estimated by y₁ = 1.28x + 57.82 (R² = 0.94) and y₂ = 0.57x + 133.28 (R² = 0.86). HG_m is estimated by y_l = 0.0041x + 0.86 (R² = 0.90) and y₂ = 0.0011x + 1.16 (R² = 0.84). WH_m is estimated by y₁ = 0.0022x + 1.03 (R² = 0.85) and y₂ = 0.0006x + 1.22 (R² = 0.80). BL_m is estimated by y₁ = 0.0038x + 0.77 (R² = 0.92) and y₂ = 0.0009x + 1.09 (R² = 0.85). HH_m is estimated by y₁ = 0.0024x + 1.07 (R² = 0.87) and y₂ = 0.0006x + 1.27 (R² = 0.78).     

The effect of low dose rocuronium bromide on eyeball position, muscle relaxation, and ventilation in dogs

A central eyeball position is often required during sedation or anaesthesia to facilitate examination of the eye. However, use of neuromuscular blockade to produce a central eye position may result in depressed ventilation. This study evaluated the eyeball position, muscle relaxation and changes in ventilation during general anaesthesia after the IV administration of 0.1 mg kg^?1 rocuronium. With client consent, 12 dogs of different breeds, body mass 27.2 ± 11.8 kg, aged 5.6 ± 2.8 years (mean ± SD) were anaesthetized for ocular examination. Pre‐anaesthetic medication was 0.01 mg kg^?1 medetomidine and 0.2 mg kg^?1 butorphanol IV. Anaesthesia was induced with propofol to effect and maintained with 10 mg kg^?1 hour^?1 propofol by infusion. The dogs were placed in left lateral recumbency, their trachea intubated and connected to a circle breathing system (Fi O₂ = 1.0). All dogs breathed spontaneously. The superficial peroneal nerve of the right hind leg was stimulated every 15 seconds with a train‐of‐four (TOF) stimulation pattern and neuromuscular function was assessed with an acceleromyograph (TOF‐Guard). Adequacy of ventilation was measured with the Ventrak 1550. After 10 minutes of anaesthesia to allow stabilisation of baseline values, 0.1 mg kg^?1 rocuronium was administered IV. Minute volume (Vm ), tidal volume (Vt ), respiratory rate (RR), Pe ′CO₂ and maximal depression of T1 and TOF ratio were measured. Data were analysed using a paired t‐test. The changes in the eyeball position were recorded. A total of 100 ± 33 seconds after the injection of rocuronium, T1 was maximally depressed to 62 ± 21% and the TOF ratio to 42 ± 18% of baseline values. Both variables returned to baseline after 366 ± 132 seconds (T1) and 478 ± 111 seconds (TOF). There was no significant reduction in Vm (2.32 ± 1.1 L minute^?1), Vt (124.1 ± 69.3 mL) and RR (10 ± 3.8 breaths minute^?1) and no increase in Pe ′CO₂ (6.5 ± 2.1 kPa (48.8 ± 16.1 mm Hg)) throughout the procedure. The eyeball rotated to a central position 35 ± 7 seconds after rocuronium IV and remained there for a minimum of 20 ± 7 minutes in all dogs. We conclude that rocuronium at a dose of 0.1 mg kg^?1 can be administered to dogs IV with minimal changes in ventilatory variables. The eyeball is fixed in a central position for at least 20 minutes, which greatly facilitates clinical examination.     

Pharmacokinetics of azithromycin in lactating dairy cows with subclinical mastitis caused by Staphylococcus aureus

Lucas, M. F., Errecalde, J. O., Mestorino, N. Pharmacokinetics of azithromycin in lactating dairy cows with subclinical mastitis caused by Staphylococcus aureus. J. vet. Pharmacol. Therap. 33 , 132–140. Azithromycin is a time‐dependent antimicrobial with long persistence. The main characteristics of azithromycin suggest that it could be useful for treating bovine mastitis caused by Staphylococcus aureus. To investigate this possibility, its pharmacokinetic (PK) behavior was studied. Six Holstein lactating cows with subclinical mastitis were administered two 10 mg/kg intramuscular (i.m.) doses of azithromycin, with a 48‐h interval. Milk and plasma concentrations were measured by microbiological assay. The MIC₉₀ was determined in 51 S. aureus isolations to calculate pharmacokinetic/pharmacodynamic (PK/PD) parameters. Milk maximal concentration (C_max) was 7.76 ± 1.76 μg/mL (16.67 h post‐first administration) and 7.82 ± 2.18 μg/mL (14 h post‐2^nd administration). In plasma C_max was 0.18 ± 0.03 μg/mL (2 h post‐1^rst administration) and 0.11 ± 0.03 μg/mL (14 h post‐2^nd administration). Azithromycin was eliminated from the milk with a half‐life (T½λ) of 158.26 ± 137.7 h after 2^nd administration, meanwhile plasma T½λ resulted shorter(13.97 ± 11.1 h). The mean area under the concentration vs. time curve from 0 to 24 h (AUC_0‐24h) was 153.82 ± 34.66 μg·h/mL in milk secretion and 2.61 ± 0.59 μg·h/mL in plasma. Infection presence in the quarters had a significant effect (P < 0.05) on the area under the concentration vs. time curve from 0 to infinity (AUC_0‐∞) and clearance from the mammary gland (Cl_mam/F). Moreover, it had influence on milk bioavailability (F_milk), T½λ, AUC_0‐∞ and mean residence time (MRT) in milk, which values resulted increased in mastitic quarters. In this study, it was determined that the production level and the mammary health status have an influence on PK parameters of azithromycin treatments in bovine mastitis.     

The isoflurane sparing effect of a medetomidine constant rate infusion in horses

This clinical study analysed the anaesthetic sparing effect of a medetomidine constant rate infusion (CRI) during isoflurane anaesthesia in horses. Forty healthy horses undergoing different types of orthopaedic and soft tissue surgeries were studied in a randomized trial. Orthopaedic surgeries were primarily arthroscopies and splint bone extractions. Soft tissue surgeries were principally castrations with one ovariectomy. All horses received 0.03 mg kg^?1 acepromazine IM 1 hour prior to sedation. Group A (11 orthopaedic and nine soft tissue surgeries), was sedated with 1.1 mg kg^?1 xylazine IV, group B (13 orthopaedic and seven soft tissue surgeries) with 7 µg kg^?1 medetomidine IV. Anaesthesia was induced in both groups with 2.2 mg kg^?1 ketamine and diazepam 0.02 mg kg^?1 IV. Maintenance of anaesthesia was with isoflurane (ISO) in 100% oxygen, depth of anaesthesia was always adjusted by the first author. Group B received an additional CRI of 3.5 µg kg^?1 hour^?1 medetomidine. Respiratory rate (RR), heart rate (HR), mean arterial blood pressure (MAP), Fe ′ISO and Fe ′CO₂ were monitored with a methane insensitive monitor (Cardiocap 5, Ohmeda, Anandic, Diessenhofen) and noted every 5 minutes. Arterial blood was withdrawn for gas analysis (PaO₂, PaCO₂) 5 minutes after the induction of anaesthesia and every 30 minutes thereafter. Dobutamine (DOB) was given as a CRI to maintain mean arterial blood pressure above 70 mm Hg. Data were averaged over time (sum of measurements/number of measurements) and tested for differences between groups by unpaired t‐tests. There were no significant differences between the groups in terms of body mass (group A, 508 ± 73.7 kg; group B, 529.25 ± 78.4 kg) or duration of anaesthesia (group A, 125.5 ± 36 minutes; group B, 121.5 ± 48.4 minutes). The mean Fe ′ISO required to maintain a surgical plane of anaesthesia was significantly higher in group A (1.33 ± 0.13%) than in group B (1.07 ± 0.19%; p = 2.78 × 10^?5). Heart rate was different between the two groups (group A, 42.2 ± 8.3; group B, 32.6 ± 3.5; p = 8.8 × 10^?5). Dobutamine requirements were higher in group A (group A, 0.72 ± 0.24 μg kg^?1 minute^?1; group B, 0.53 ± 0.23 μg kg^?1 minute^?1; p = 0.023). Respiratory rate, Fe ′CO₂, PaO₂, PaCO₂ were not different between the groups. Adjustment of anaesthetic depth subjectively was easier with the medetomidine infusion and isoflurane (group B) than with isoflurane as a sole agent (group A). In group A 12 horses and in group B five horses showed purposeful movements on 27 (A) and 12 (B) occasions. They were given thiopental (group A, 0.0114 mg kg^?1 minute^?1; group B, 0.0023 mg kg^?1 minute^?1). In group A, a further 17 horses were given ketamine to deepen anaesthesia (52 occasions, 0.00426 mg kg^?1 minute^?1) whereas in group B only nine horses needed ketamine (34 occasions, 0.00179 mg kg^?1 minute^?1). An infusion of 3.5 µg kg^?1 MED during ISO anaesthesia resulted in a significantly reduced ISO requirement.     

Pharmacokinetic–pharmacodynamic modelling of meperidine in goats (I): pharmacokinetics

Qiao, G.-L., Fung, K.-F. Pharmacokinetic-pharmacodynamic modelling of meperidine in goats (I): pharmacokinetics. J. vet. Pharmacol. Therap. 16 , 426–437. Plasma and cerebrospinal fluid (CSF) pharmacokinetics of meperidine were investigated after intramuscular (i.m.) or intravenous (i.v.) administration at a dose of 5 mg/kg in adult goats. After i.m. dosing, the plasma profile was best described by a one-compartment open model. In healthy (n = 16) and postoperative (n = 16) goats, the parameters were, respectively: /_max 8.3 ± 3.9 and 9.2 ± 5.5 min, V_d 2.763 ±1.231 and 3.929 ±2.101 1/kg, Cl_b 0.125 ± 0.036 and 0.087 ± 0.025 1/kg/min, K_c 0.0563 ± 0.0358 and 0.0271 ± 0.0136 min^-1. The plasma profile was best fitted by a two-compartment open model following i.v. injection. In this case, the parameters for healthy (n= 7) and post-operative (n= 13) goats were, respectively: V_d 5.212 ± 1.992 and 5.085 ± 2.288 1/kg, Cl_b 0.096 ± 0.028 and 0.075 ± 0.026 1/kg/min, P 0.0211 ± 0.0093 and 0.0160 ± 0.0052 min.^-1. There were, however, a few individuals with a prolonged elimination phase. Bioavailability of i.m. meperidine was 66.5 ± 15.8% in healthy (n= 6) goats, but much higher in postoperative (n = 10) ones at 94.6 ± 30.0%. Meperidine diffused into and out of CSF according to a first-order rate process. The time-course of CSF drug concentration was simulated by a biexponential function. CSF kinetic parameters of i.m. meperidine for healthy (n = 7) and postoperative (n = 13) goats were: elimination rate constant (K_ei) 0.0269 ± 0.0131 and 0.0305 ± 0.0177 min“¹, peak CSF concentration time (T_naxl) 15.9 ± 5.0 and 17.0 ± 6.9 min. For the i.v. dosed healthy (n = 6) and postoperative (n = 8) animals, K_el was 0.0408 ± 0.0107, 0.0414 ± 0.0123 min^-1 and 7_maxt was 10.0 ± 5.0 and 7.7 ± 2.5 min, respectively. It was demonstrated that an obviously lower peak concentration can be reached significantly later in CSF than in plasma, and the kinetic behaviour of meperidine in plasma is different from that in the CSF, indicating meperidine analgesia might not be predicted by simple extrapolation from the kinetic data.     

Effectiveness of controlled internal drug release device treatment to alleviate reproductive seasonality in anestrus lactating or dry Barki and Rahmani ewes during non‐breeding season

This study aimed to evaluate the effectiveness of hormonal treatments on ovarian activity and reproductive performance in Barki and Rahmani ewes during non‐breeding season. Forty‐eight multiparous ewes, 24 Barki and 24 Rahmani ewes were divided into two groups, 12 lactating and 12 dry ewes for each breed. Controlled internal drug release (CIDR) device was inserted in all ewes for 14 days in conjunction with intramuscular 500 IU equine chronic gonadotrophin (eCG) at day of CIDR removal. Data were analysed using PROC MIXED of SAS for repeated measures. Breed, physiological status and days were used as fixed effects and individual ewes as random effects. Barki ewes recorded higher (p < .05) total number of follicles, number of large follicles, serum estradiol concentration and estradiol: progesterone (E₂:P₄) ratio compared to Rahmani ewes. Lactating ewes recorded higher (p < .05) number of small follicles and lower concentration of total antioxidant capacity (TAC) compared to dry ewes. Number and diameter of large follicles recorded the highest (p < .05) values accompanied with disappearance of corpora lutea at day of mating. Serum progesterone concentration recorded lower (p < .05) value at day of mating and the highest (p < .05) value at day 35 after mating. CIDR‐eCG protocol induced 100% oestrous behaviour in both breeds, but Rahmani ewes recorded longer (p < .05) oestrous duration compared to Barki. Conception failure was higher (p < .05) in Barki compared to Rahmani ewes. In conclusion, CIDR‐eCG protocol was more potent in improving ovarian activity in Barki compared to Rahmani ewes, but this protocol seems to induce hormonal imbalance in Barki ewes that resulted in increasing conception failure compared to Rahmani ewes.     

Relevance of age at slaughter on meat quality of turkeys stunned with CO2

1. The objective of this work was to determine the effect of slaughter age and stunning method on the quality of turkey meat from poultry processing plants.

2. One hundred B.U.T. Premium turkeys were divided into 4 groups of 25 animals according to slaughter age (15 or 17 weeks) and CO₂ stunning procedure (G1 stepwise: step1: 30% CO₂, 15 s; step 2: 55% CO₂, 40 s; step 3: 70% CO₂, 45 s; G2: progressive increase of the CO₂ concentration at a rate of 0.8% per s for 100 s). The quality of the breast meat was determined in fillets taken at different post-mortem times.

3. There were differences between the stunning groups for several variables (pH: 6.01 ± 0.01 and 5.95 ± 0.02; a*: ?1.84 ± 0.05 and ?2.21 ± 0.04; b*: 4.99 ± 0.15 and 4.68 ± 0.16; drip loss: 0.85 ± 0.02 and 0.71 ± 0.02 for G1 and G2, respectively), while no significant differences were found for L*, cooking loss and texture analysed with a Warner Bratzler Shear Force cell (WBSF).

4. Slaughter age had a significant effect on all the parameters studied (pH: 6.01 ± 0.01 and 5.95 ± 0.01; a*: ?2.21 ± 0.05 and ?1.88 ± 0.05, b*: 5.50 ± 0.17 and 4.42 ± 0.15; drip loss: 0.71 ± 0.02 and 0.86 ± 0.02, cooking loss: 12.56 ± 0.22 and 14.69 ± 0.16 for turkeys slaughtered at 15 and 17 w, respectively) except on L* and WBSF.

5. The ageing of the meat affected pH, colour values, drip loss and WBSF, with differing degrees of evolution: mean values of L* (39.36 ± 0.35. 45.77 ± 0.20 and 46.30 ± 0.24, for 20 min, 24 h and 7 d post mortem, respectively) and drip loss (0.75 ± 0.03 and 0.84 ± 0.02 for 24 h and 7 d post mortem, respectively) increased, those of a* (?1.77 ± 0.08, ?1.94 ± 0.07 and ?2.22 ± 0.05 for 20 min, 24 h and 7 d post mortem, respectively) and WBSF decreased (3.73 ± 0.06 and 2.63 ± 0.04 for 24 h and 7 d post mortem, respectively), those of pH decreased in the first 24 h and remained stable for the next 6 d (6.19 ± 0.02, 5.87 ± 0.01 and 5.88 ± 0.01), and those of b* increased in the first 24 h post-mortem and remained stable for the next 6 d (3.26 ± 0.31, 5.86 ± 0.16 and 5.47 ± 0.08).

6. The results revealed no critical differences between stunning methods, and suggest that animals slaughtered at 15 weeks present higher quality meat than those slaughtered at 17 weeks.     

Variation in the KRTAP6-3 gene and its association with wool characteristics in Pakistani sheep breeds and breed-crosses

This study investigated variation in the keratin-associated proteins gene, KRTAP6-3, in 5 Pakistani sheep breeds/crosses using polymerase chain reaction-single strand confirmation polymorphism (PCR-SSCP) analysis. Different banding patterns were revealed, including previously described patterns and a novel pattern (named variant H). The amplified PCR product of the novel banding pattern was directly sequenced, and a synonymous nucleotide variation c.51T>C was revealed. Among the wool traits assessed, a strong correlation (r = 0.929; P < 0.001) was observed between fibre diameter standard deviation (FDSD) and coefficient of variation of fibre diameter (CVFD), between FDSD and medullation (r = 0.720; P < 0.001), between FDSD and medullation standard deviation (MeSD) (r = 0.734; P < 0.001), between MeSD and coefficient of variance of medullation (CVMed), (r = 0.903, P < 0.001), and between CVFD and medullation (r = 0.660), CVFD and MeSD (r = 0.786; P < 0.001), CVFD and CVMed (r = 0.701; P < 0.001) and medullation and MeSD (r = 0.771; P < 0.001). Variant B was found to be associated (P = 0.018) with CVFD; the presence of B being associated with a higher CVFD, than in its absence (41.08 ± 3.98 versus 36.34 ± 3.08). Variant C was associated with CVMed (P = 0.040), where sheep with C had a lower CVMed than sheep where it was absent. Variation in KRTAP6-3 was found to affect fibre diameter related traits of wool.

     

Lithium dilution cardiac output and oxygen delivery in conscious dogs with systemic inflammatory response syndrome

Objective: Compare cardiac index (CI) and oxygen delivery index (DO₂I) in conscious, critically ill dogs to control dogs; evaluate the association of CI and DO₂I with outcome. Design: Prospective non‐randomized clinical study. Setting: Veterinary teaching hospital. Animals: Eighteen client‐owned dogs with systemic inflammatory response syndrome (SIRS) and 8 healthy control dogs. Measurements and Main Results: CI of dogs with SIRS was measured using lithium dilution at times 0, 4, 8, 16, and 24 hours. Data collected included physical exam, arterial blood gas (ABG) and hemoximetry. CI of control dogs was measured 3 times with 1 measurement of ABG. Mean CI ± SE in SIRS patients was 3.32 ± 0.95 L/min/m²; lower than controls at 4.18 ± 0.22 L/min/m² (P<0.001). Mean DO₂I ± SE in SIRS patients was 412.91 ± 156.67 mL O₂/min/m²; lower than controls at 785.24 ± 45.99 mL O₂/min/m² (P<0.001). There was no difference in CI (P=0.49) or DO₂I (P=0.51) for dogs that survived to discharge versus those that did not. There was no difference in mean CI (P=0.97) or DO₂I (P=0.50) of survivors versus non‐survivors for 28‐day survival. Survivors had lower blood glucose (P=0.03) and serum lactate concentrations (P=0.04) than non‐survivors. Conclusions: CI and DO₂I in conscious dogs with SIRS were lower than control dogs, which differs from theories that dogs with SIRS are in a high cardiac output state. CI and DO₂I were not significantly different between survivors and non‐survivors. Similar to previous studies, lactate and glucose concentrations of survivors were lower than non‐survivors.     

Congenital stationary night blindness is associated with the leopard complex in the Miniature Horse

Objective To determine if congenital stationary night blindness (CSNB) exists in the miniature horse in association with leopard complex spotting patterns (LP), and to investigate if CSNB in the miniature horse is associated with three single nucleotide polymorphisms (SNPs) in the region of TRPM1 that are highly associated with CSNB and LP in Appaloosas. Animals studied Three groups of miniature horses were studied based on coat patterns suggestive of LP/LP (n = 3), LP/lp (n = 4), and lp/lp genotype (n = 4). Procedures Horses were categorized based on phenotype as well as pedigree analysis as LP/LP, LP/lp, and lp/lp. Neurophthalmic examination, slit‐lamp biomicroscopy, indirect ophthalmoscopy, and scotopic flash electroretinography were performed on all horses. Hair samples were processed for DNA analysis. Three SNPs identified and associated with LP and CSNB in the Appaloosa were investigated for association with LP and CSNB in these Miniature horses. Results All horses in the LP/LP group were affected by CSNB, while none in the LP/lp or lp/lp groups were affected. All three SNPs were completely associated with LP genotype (χ² = 22, P << 0.0005) and CSNB status (χ² = 11, P < 0.0005). Conclusions The Miniature Horse breed is affected by CSNB and it appears to be associated with LP as in the Appaloosa breed. The SNPs tested could be used as a DNA test for CSNB until the causative mutation is determined.     

Comparison of sevoflurane and isoflurane anesthetic index in unpremedicated dogs

Anesthetic respiratory effects of sevoflurane (SEVO) were compared with isoflurane (ISO) in unpremedicated dogs. Minimum alveolar concentration (MAC), apneic concentration (AC), and anesthetic index (AI) of SEVO and ISO were determined in eight 1‐year‐old healthy dogs, weighing 19 ± 3 kg (mean ± SEM) in a randomized complete block multiple cross‐over design. Dogs were mask‐induced with either SEVO or ISO in 100% oxygen. Following endotracheal intubation, dogs were instrumented, mechanically ventilated, and MAC was determined using a tail‐clamp method. Next, spontaneous ventilation was re‐established, and anesthetic concentration was increased to determine the AC. Throughout the anesthetic event, heart rate (HR), systolic blood pressure (SAP), mean blood pressure (MAP), diastolic blood pressure (DAP), respiratory rate (RR), end‐tidal carbon dioxide (Pe ′CO₂), and oxyhemoglobin saturation (SpO₂) were recorded at 3‐minute intervals. Following AC determination, AI was calculated as AC/MAC, and dogs were allowed to recover. Each dog was anesthetized four times (twice with ISO and SEVO each) at 1‐week intervals. All data were analyzed using the two‐way anova . Multiple comparisons were performed between ISO and SEVO treatments. Statistical significance was set at p < 0.05. Significant differences were noted between agents for MAC (SEVO, 2.13 ± 0.10%; ISO, 1.38 ± 0.14%; p < 0.0001), AC (SEVO, 7.34 ± 0.13%; ISO, 3.60 ± 0.13%; p < 0.0001), and AI (SEVO, 3.46 ± 0.22; ISO, 2.63 ± 0.14; p = 0.0002). Physiologic parameters were compared between SEVO and ISO at 1MAC, 2MAC, 3MAC, and AC. No differences were noted between SEVO and ISO treatments for cardiovascular parameters (HR, SAP, MAP, DAP). Significant differences were noted, favoring SEVO, for all respiratory parameters (RR, Pe ′CO₂, SpO₂) at increasing MAC multiples. Additionally, regression analysis was conducted for physiologic variable data points. Analysis of Pe ′CO₂ data points demonstrated a significant slope difference of ?6.47 ± 1.02 (B_SEVO ? B_ISO; p < 0.0001; r² = 0.6042) favoring SEVO. While expected dose‐related ventilatory depression was noted for both agents, all the respiratory parameters for SEVO demonstrated less respiratory depression than ISO at equipotent doses. These results indicated that SEVO caused less dose‐dependent ventilatory depression than ISO, having a significantly higher AI and causing less detrimental change in pulmonary parameters at increasing levels of MAC.     

Pharmacokinetics of lincomycin following single intravenous administration in buffalo calves

Lincomycin 10 mg kg^?1, IV in buffalo calves followed two-compartment open model with high distribution rate constant α (11.2?±?0.42 h^?1) and K ₁₂/K ₂₁ ratio (4.40?±?0.10). Distribution half-life was 0.06?±?0.01 h and AUC was 41.6?±?1.73 μg mL^?1 h. Large Vd_area (1.15?±?0.03 L kg^?1) indicated good distribution of lincomycin in various body fluids and tissues. Peak plasma level of lincomycin (71.8?±?1.83 μg mL^?1) was observed at 1 min as expected by IV route. The elimination half-life and MRT of lincomycin were short (3.30?±?0.08 and 4.32?±?0.11 h, respectively). Lincomycin 10 mg kg^?1 IV at 12-h interval would be sufficient to maintain T?>?MIC above 60 % for bacteria with minimum inhibitory concentrations (MIC) values ≤1.6 μg mL^?1. Favourable pharmacokinetic profile in buffalo calves and a convenient dosing interval suggest that lincomycin may be an appropriate antibacterial in buffalo species for gram-positive and anaerobic bacterial pathogens susceptible to lincomycin.