Depletion of dexamethasone in cattle: Food safety study in dairy and beef cattle.

Dexamethasone is approved for cattle in Canada for several conditions, but no withdrawal times are currently provided on the approved labels. Recently, the list of Maximum Residues Limits for Veterinary Drugs in Foods in Canada was amended to include dexamethasone. The objectives of this study were to determine the residue depletion profile of dexamethasone after an extra-label dosage regimen in milk of healthy lactating dairy cattle (n = 18) and in edible tissues of healthy beef cattle (n = 16) and to suggest withdrawal intervals.

Pharmacokinetics of combined administration of iron dextran with meloxicam or flunixin meglumine in piglets.

Objective: The objective was to evaluate the pharmacokinetics of compounding non-steroidal anti-inflammatory drugs (NSAIDs) meloxicam or flunixin meglumine with iron dextran (ID) in piglets.

Animal: Forty piglets (8 d of age) were randomly allocated into 5 groups (8 piglets/group) and received 1 intramuscular injection in the neck of the following treatments: flunixin meglumine (2.2 mg/kg) administered alone (F) or mixed with ID (F+ID); or meloxicam (0.

Pharmacokinetics and bioavailability of ketoprofen when compounded with iron dextran for use in nursing piglets.

In Canada, piglets receive analgesia to control pain after surgical castration. There is interest in examining the potential to mix non-steroidal anti-inflammatory drugs with iron dextran prior to injection to minimize piglet handling and labor. The objective of this study was to compare pharmacokinetics and the relative bioavailability of ketoprofen given alone (3.

Tissue residue depletion of fenbendazole after oral administration in turkeys.

The objectives of this study were to determine tissue depletion of fenbendazole in turkeys and estimate a withdrawal interval (WDI). Forty-eight 9-week-old turkeys were fed fenbendazole at 30 mg/kg of feed for 7 consecutive days. Three hens and 3 toms were sacrificed every 2 days from 2 to 16 days post-treatment, and tissues were collected to determine fenbendazole sulfone (FBZ-SO) concentrations using mass spectrometry.

Effects of acute transmural pressure elevation on endothelium-dependent vasodilation in isolated rat mesenteric veins.

Background/aims: The vascular regulatory function of the endothelium can be impaired by increases in transmural pressure (TMP). We tested the hypothesis that increasing TMP impairs the endothelial dilator function of rat mesenteric small veins (MSVs).

Methods: In PGF2α-preconstricted MSVs, bradykinin (BK), sodium nitroprusside (SNP) and S-Nitroso-N-acetylpenicillamine (SNAP) concentration-response curves were generated at intermediate (6 mm Hg) and high (12 mm Hg) pressures.

Functional characteristics of alpha adrenergic and endothelinergic receptors in pressurized rat mesenteric veins.

Increasing transmural pressure can alter the functional role of post-junctional receptor subtypes. Under conditions of changing transmural pressure, we investigated the relative contributions of alpha adrenergic (α-ARs) and endothelinergic receptors to norepinephrine (NE) and endothelin (ET-1) contractile responses, respectively, in third-order rat mesenteric small veins (MSV) and arteries (MSA). NE, phenylephrine (PE), clonidine, and ET-1 concentration-response curves were constructed in the absence and presence of α-adrenergic and ET-1 receptor antagonists, respectively.

Characteristics of myogenic reactivity in isolated rat mesenteric veins.

Mechanisms of mechanically induced venous tone and its interaction with the endothelium and key vasoactive neurohormones are not well established. We investigated the contribution of the endothelium, l-type voltage-operated calcium channels (L-VOCCs), and PKC and Rho kinase to myogenic reactivity in mesenteric vessels exposed to increasing transmural pressure. The interaction of myogenic reactivity with norepinephrine (NE) and endothelin-1 (ET-1) was also investigated.

Effects of a peripheral alpha2 adrenergic-receptor antagonist on the hemodynamic changes induced by medetomidine administration in conscious dogs.

Objective: To evaluate the effects of administration of a peripheral alpha(2)-adrenergic receptor antagonist (L-659,066), with and without concurrent administration of glycopyrrolate, on cardiopulmonary effects of medetomidine administration in dogs.

Animals: 6 healthy adult dogs.

Procedures: Dogs received saline (0.

Cardiopulmonary effects of anesthetic induction with thiopental, propofol, or a combination of ketamine hydrochloride and diazepam in dogs sedated with a combination of medetomidine and hydromorphone.

Objective: To evaluate the cardiopulmonary effects of anesthetic induction with thiopental, propofol, or ketamine hydrochloride and diazepam in dogs sedated with medetomidine and hydromorphone.

Animals: 6 healthy adult dogs.

Procedures: Dogs received 3 induction regimens in a randomized crossover study.

Sedative and cardiopulmonary effects of medetomidine hydrochloride and xylazine hydrochloride and their reversal with atipamezole hydrochloride in calves.

Objective: To assess the sedative and cardiopulmonary effects of medetomidine and xylazine and their reversal with atipamezole in calves.

Animals: 25 calves.

Procedures: A 2-phase (7-day interval) study was performed.