Cardiovascular and pulmonary effects of hetastarch plus hypertonic saline solutions during experimental endotoxemia in anesthetized horses

BACKGROUND: Small volume resuscitation has been advocated as a beneficial therapy for endotoxemia in horses but this therapy has not been investigated in a prospective manner. The objective of this study was to determine the cardiopulmonary effects of small-volume resuscitation using hypertonic saline solution (HSS) plus Hetastarch (HES) during experimental endotoxemia in anesthetized horses. HYPOTHESIS: Treatment of horses with induced endotoxemia using HES-HSS does not alter the response of various cardiopulmonary indices when compared to treatment with either small- or large-volume isotonic crystalloid solutions. ANIMALS: Eighteen healthy horses were randomly assigned to 1 of 3 groups. Anesthesia was maintained with halothane. Endotoxemia was induced by administering 50 microg/kg of Escherichia coli endotoxin IV. The horses were treated over 30 minutes with 15 mL/kg of balanced polyionic crystalloid solution (control), 60 mL/kg of balanced polyionic crystalloid solution (ISO), or 5 mL/kg of HSS followed by 10 mL/kg of HES (HSS-HES). METHODS: Prospective randomized trial. RESULTS: Cardiac output (CO) after endotoxin infusion increased significantly (P < .05) from baseline in all groups, whereas mean central venous pressure increased significantly (P < .05) in the ISO group only. Mean pulmonary artery pressure increased from baseline (P < .05) in horses treated with isotonic fluids and HSS-HES. There was no effect of treatment with HSS-HES on CO, systemic vascular resistance (SVR), mean arterial pressure, blood lactate concentrations, or arterial oxygenation. CONCLUSIONS AND CLINICAL IMPORTANCE: The use of HSS-HES failed to ameliorate the deleterious hemodynamic responses associated with endotoxemia in horses. The clinical value of this treatment in horses with endotoxemia remains unconfirmed.     

Pharmacokinetics of penicillin G procaine versus penicillin G potassium and procaine hydrochloride in horses

OBJECTIVE: To compare the pharmacokinetics of penicillin G and procaine in racehorses following i.m. administration of penicillin G procaine (PGP) with pharmacokinetics following i.m. administration of penicillin G potassium and procaine hydrochloride (PH). ANIMALS: 6 healthy adult mares. PROCEDURE: Horses were treated with PGP (22,000 units of penicillin G/kg of body weight, i.m.) and with penicillin G potassium (22,000 U/kg, i.m.) and PH (1.55 mg/kg, i.m.). A minimum of 3 weeks was allowed to elapse between drug treatments. Plasma and urine penicillin G and procaine concentrations were measured by use of high-pressure liquid chromatography. RESULTS: Median elimination phase half-lives of penicillin G were 24.7 and 12.9 hours, respectively, after administration of PGP and penicillin G potassium. Plasma penicillin G concentration 24 hours after administration of penicillin G potassium and PH was not significantly different from concentration 24 hours after administration of PGP. Median elimination phase half-life of procaine following administration of PGP (15.6 hours) was significantly longer than value obtained after administration of penicillin G potassium and PH (1 hour). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that i.m. administration of penicillin G potassium will result in plasma penicillin G concentrations for 24 hours after drug administration comparable to those obtained with administration of PGP Clearance of procaine from plasma following administration of penicillin G potassium and PH was rapid, compared with clearance following administration of PGP.     

Disodium-fosfomycin pharmacokinetics and bioavailability in post weaning piglets

Disodium-fosfomycin pharmacokinetics has been studied in different species after oral, intravenous, intramuscular and subcutaneous administration. At present there are neither documented clinical experiences of the use of fosfomycin in pigs nor any published studies in weaning piglets, although it is a period of high incidence of infectious diseases. The pharmacokinetics and the bioavailability of sodium fosfomycin were studied in post weaning piglets after intravenous and intramuscular administration of 15 mg/kg of body weight. Plasma concentrations were measured by a high-performance liquid ms/ms. After IV administration the area under the fosfomycin concentration:time curve in plasma was AUC_(0–12) of 120.00 ± 23.12 μg h/ml and the volume of distribution (Vd) of 273.00 ± 40.70 ml/kg. The elimination was rapid with a plasma clearance of 131.50 ± 30.07 ml/kg/h and a T_1/2 of 1.54 ± 0.40 h. Peak serum concentration (C_max), T_max, AUC_(0–12) and bioavailability for the IM administration were 43.00 ± 4.10 μg/ml, 0.75 ± 0.00 h, 99.00 ± 0.70 μg h/ml and 85.5 ± 9.90% respectively. Different authors have determined a minimum inhibitory concentration (MIC₉₀) ranging from 0.25 μg/ml for Streptococcus sp. and 0.5 μg/ml for Escherichia coli. Considering the above, and according to the values of plasma concentration vs time profiles observed in this study, effective plasma concentrations of fosfomycin for sensitive bacteria can be obtained following IV and IM administration of 15 mg/kg in piglets.     

Aldicarb poisoning of dogs and cats in Gauteng during 2003

A survey of aldicarb poisoning in companion animals was conducted by posting questionnaires to all private practitioners in Gauteng Province, South Africa. The survey was designed to determine the percentage of aldicarb cases seen, treatment regimen, clinical signs observed, proposals for preventative actions and more effective treatments. Other questions included duration of treatment, survival rate, cost to clients, post mortem findings and reasons for poisonings.     

Mitotane treatment in a dog with a recurring adrenocortical carcinoma--a case report]

In a 7 year old female poodle an adrenocortical tumor was diagnosed on basis of laboratory and ultrasonographic examinations. One year after adrenalectomy, a relapse was diagnosed, at that time the suspicion of metastases in the liver arose for the first time. By treatment with Mitotane in a dose aiming at completely destroying the adrenal cortex, a complete disappearance of the tumor as well as a dramatic reduction of the size of the metastases could be achieved. 12 months after the begin of the chemotherapy, the dog is in good general condition.     

Production of an equine anti-bovine leukocyte serum.

A method is described for production of an equine anti-bovine leukocyte serum (EABLS). Leukocytes were harvested from the milk of cow's udders which had been irritated with endotoxin. The washed leukocytes as antigens were administered to 2 horses in a series of subcutaneous and intravenous injections. There was a variably progressive increase in total serum proteins and a decrease in albumin/blobulin ratios, but the most pronounced change was an increase in beta2-globulins. Accompanying these changes was an increase in the number of precipitin lines as shown by Ouchterlony analysis. Four old cows and 2 calves were intravenously given a 50- and 20-ml dose, respectively, of the EABLS. Two of the cows and 1 of the calves were given the EABLS which had been heated to 56 C for 30 minutes. Both calves and the 2 cows given heated EABLS and 1 cow given unheated EABLS developed marked neutropenia within the 1st hour. The 4th cow given unheated EABLS developed only slight neutropenia. It was concluded that there may be variation in the individual animal's susceptibility to the neutropenia-inducing activity of EABLS.     

Genetic and environmental parameters for traits derived from the Brody growth curve and their relationships with weaning weight in Angus cattle

Direct and maternal genetic and environmental variances and covariances were estimated for weaning weight and growth and maturing traits derived from the Brody growth curve. Data consisted of field records of weight measurements of 3,044 Angus cows and 29,943 weaning weight records of both sexes. Growth traits included weights and growth rates at 365 and 550 d, respectively. Maturing traits included the age of animals when they reached 65% of mature weight, relative growth rates, and degrees of maturity at 365 and 550 d. Variance and covariance components were estimated by REML from a set of two-trait animal models including weaning weight paired with a growth or maturing trait. Weaning and cow contemporary groups were defined as fixed effects. Random effects for weaning weight included direct genetic, maternal genetic, and permanent environmental effects. For growth and maturing traits, a random direct genetic effect was included in the model. Direct heritability estimates for growth traits ranged from .46 to .52 and for maturing traits from .31 to .34. Direct genetic correlations between weaning weight and weights and growth rates at 365 and 550 d ranged from .56 to .70. Correlations of maternal weaning genetic effects with direct genetic effects on weights at 365 and 550 d were positive, but those with growth rates were negative. Between weaning weight and degrees of maturity at both 365 and 550 d, direct genetic correlation estimates were .55 and maternal genetic correlations estimates were -.05, respectively. Direct genetic correlations of weaning weight with relative growth rates and age at 65% of mature weight ranged from .04 to .06, and maternal-direct genetic correlation estimates ranged from -.50 to -.56, respectively. These estimates indicate that higher genetic capacity for milk production was related to higher body mass and degrees of maturity between 365 and 550 d of age but was negatively related to absolute and relative growth rates in that life stage.