A Model for comparing reduced impact logging with conventional logging for an Eastern Amazonian Forest

Using data from a logging experiment in the eastern Brazilian Amazon region, we develop a matrix growth and yield model that captures the dynamic effects of harvest system choice on forest structure and composition. Multinomial logistic regression is used to estimate the growth transition parameters for a 10-year time step, while a Poisson regression model is used to estimate recruitment parameters. The model is designed to be easily integrated with an economic model of decisionmaking to perform tropical forest policy analysis. The model is used to compare the long-run structure and composition of a stand arising from the choice of implementing either conventional logging techniques or more carefully planned and executed reduced-impact logging (RIL) techniques, contrasted against a baseline projection of an unlogged forest. Results from “log and leave” scenarios show that a stand logged according to Brazilian management requirements will require well over 120 years to recover its initial commercial volume, regardless of logging technique employed. Implementing RIL, however, accelerates this recovery. Scenarios imposing a 40-year cutting cycle raise the possibility of sustainable harvest volumes, although at significantly lower levels than is implied by current regulations. Meeting current Brazilian forest policy goals may require an increase in the planned total area of permanent production forest or the widespread adoption of silvicultural practices that increase stand recovery and volume accumulation rates after RIL harvests.     

Use of continuous positive airway pressure in the acute management of laryngeal paralysis in a cat

Continuous positive airway pressure (CPAP) has been is used widely in humans to manage obstructive sleep apnoea syndrome, but it has not been widely used in animals. A brachycephalic cat, with previously undiagnosed laryngeal paralysis, that developed acute upper respiratory tract obstruction on recovery from anaesthesia, is presented. The condition was managed by CPAP, delivered via a facial mask.     

Pharmacokinetics of ceftiofur sodium in equine pregnancy

Eleven pregnant pony mares (D270‐326) were administered ceftiofur sodium intramuscularly at 2.2 mg/kg (n = 6) or 4.4 mg/kg (n = 5), once daily. Plasma was obtained prior to ceftiofur administration and at 0.5, 1, 2, 4, 8, 12, and 24 hr after administration. Eight pony mares were re‐enrolled in the study at least 3 days from expected foaling to ensure steady‐state concentrations of drug at the time of foaling. Mares were administered ceftiofur sodium (4.4 mg/kg, IM) daily until foaling. Parturition was induced using oxytocin 1 hr after ceftiofur sodium administration. Allantoic and amniotic fluid, plasma, and colostrum samples were collected at time of foaling. Serial foal plasma samples were obtained. Placental tissues were collected. Desfuroylceftiofur acetamide (DCA) concentrations were measured in samples by high‐performance liquid chromatography (HPLC). Mean (±SD) peak serum concentrations of DCA were 3.97 ± 0.50 μg/ml (low dose) and 7.45 ± 1.05 μg/ml (high dose). Terminal half‐life was significantly (p = .014) shorter after administration of the low dose (2.91 ± 0.59 hr) than after administration of the high dose (4.10 ± 0.72 hr). The mean serum concentration of DCA from mares at time of foaling was 7.96 ± 1.39 μg/ml. The mean DCA concentration in colostrum was 1.39 ± 0.70 μg/ml. DCA concentrations in allantoic fluid, amniotic fluid, placental tissues, and foal plasma were below the limit of quantification (<0.1 μg/ml) and below the minimum inhibitory concentration of ceftiofur against relevant pathogens. These results infer incomplete passage of DCA across fetal membranes after administration of ceftiofur sodium to normal pony mares.     

Animal Identification: I. Liquid Nitrogen Branding of Cattle

A number of branding tools of various metals and various sizes in combination with several wetting agents were cooled with liquid nitrogen and applied for different lengths of time to calves and mature cattle. White hair appeared in the shape of the brand on the animals in place of dark hair when the application was properly carried out. Best results can be obtained by using metal irons at least 25 millimeters thick and 14 millimeters wide with xylol as a wetting agent for ten seconds in young or thin skinned animals and up to twenty seconds in mature or thick skinned animals.     

Pharmacokinetics of once-daily amikacin in healthy foals and therapeutic drug monitoring in hospitalized equine neonates

The objectives of this study were to investigate the pharmacokinetics of once-daily amikacin in healthy neonates, to determine amikacin concentrations in hospitalized foals, and to determine the minimum inhibitory concentrations (MICs) of amikacin against gram-negative isolates from blood cultures in septic foals. Median half-life, clearance, and volume of distribution of amikacin in healthy 2- to 3-day-old foals after administration of an intravenous bolus of amikacin (25 mg/kg) were 5.07 hours (4.86-5.45 hours), 1.82 mL/min/kg (1.35-1.97 mL/min/kg), and 0.785 L/kg (0.638-0.862 L/kg), respectively. Statistically significant (P <.05) decreases in area under the curve (14% decrease), mean residence time (19% decrease), and C24h plasma amikacin concentrations (29% decrease) occurred between days 2-3 and 10-11. Plasma amikacin concentrations in healthy foals at 0.5 hours (C0.5h) were significantly higher (P = .02) than those of hospitalized foals. Sepsis, prematurity, and hypoxemia did not alter amikacin concentrations. The MIC at which 90% of all gram-negative isolates from equine neonatal blood cultures were inhibited by amikacin was 4 microg/mL, suggesting that amikacin C0.5h of 40 microg/mL should be targeted to achieve a maximum serum concentration to MIC ratio of 10:1. The proportion of foals with C0.5h 40 microg/mL was significantly higher (P < .0001) in hospitalized foals receiving a dose of amikacin at 25 mg/kg (22/24 or 92%) than in foals receiving a dose at 21 mg/kg (9/25 or 36%), whereas no difference was found in the proportion of foals with C24h concentrations > or = 3 microg/mL between the 2 groups. An initial dose at 25 mg/kg is recommended for once-daily amikacin in equine neonates.     

Treating the Mare with Placentitis: A Clinical Approach

Placentitis is a challenging condition in the mare to both diagnose and treat. The identification of clinical signs, use of ultrasonography, and interpretation of laboratory values (serum progestin and mammary secretion electrolytes) will be described. Current therapies for treating placental infections will be discussed. In addition, recommendations for managing the postpartum mare and neonate will be provided.     

Disposition of firocoxib in late pregnant and early postpartum mares

Pregnancy induces several physiologic changes that might impact the bioavailability, distribution, metabolism, and excretion of drugs. The objective of this study was to determine the effects of pregnancy on the disposition of oral firocoxib in mares. Seven pony mares received oral firocoxib paste at a dose of 0.1 mg/kg during late pregnancy and again 12 to 33 days postpartum. Firocoxib concentrations were measured in plasma by HPLC with ultraviolet detection. Maximum plasma concentrations were significantly lower in pregnant (50.0 ± 21.8 ng/mL) than in postpartum (73.7 ± 25.6 ng/mL) mares. Plasma concentrations 24 h after administration, time to maximum plasma concentrations, and area under the plasma concentration versus time curve were not significantly different between late pregnancy and the postpartum period in mares.