Zoetis (Canada)

ObjectivesThe aim of the present study was to assess the gamma-aminobutyric acid type A (GABAA) receptor antagonist flumazenil and its effect on the anesthetic activity of the GABAA receptor agonist alfaxalone when administered intravenously in cats.MethodsA prospective, randomized, blinded, two-period two-treatment crossover study was conducted. Eight (six male, two female) healthy adult neutered cats, 4.5–7.0 kg body weight, owned by IndyVet Emergency and Specialty Hospital were enrolled. Cats were randomly assigned to one of two treatment groups, flumazenil or saline (period 1). During period 2, cats were administered the opposite treatment. Treatment was either 0.1 mg/kg flumazenil or an equal volume of 0.9% sodium chloride. Before treatment, a published, abbreviated alfaxalone protocol was administered, consisting of an intravenous (IV) dose of 2 mg/kg over 1 min, followed by an abbreviated two-step IV alfaxalone infusion of 0.4 mg/kg/min for 10 mins, then 0.3 mg/kg/min for 30 mins. Physiologic parameters, time to lateral recumbency, sternal recumbency and standing, duration of anesthesia, quality of induction and maintenance of anesthesia, and quality of recovery were assessed.ResultsThe treatment by time interaction was not significant for any variable. Pulse rate was significantly higher in the flumazenil group than the saline group (mean 176.01 vs 169.57; P = 0.0067).Conclusions and relevanceFlumazenil administered at 0.1 mg/kg intravenously over 1 min did not antagonize the effects of alfaxalone in cats. Further investigations are required to investigate an appropriate dose or other drug to antagonize alfaxalone and its judicious use in clinical settings.

Abstract Numerous studies have shown that gilts treated with Improvest® have greater carcass weights and increased ADG compared with untreated gilts. To develop the optimum nutritional program for Improvest-treated gilts, a randomized 5×2 factorial design of dietary lysine levels (90, 100, 110, 120, and 130% of NRC recommendations) with or without Improvest was performed. Gilts were housed in 120 pens (4 pigs/pen) at 8 weeks of age (day 0). Gilts and feed were weighed immediately prior to each dietary phase change (days 0, 21, 42, 70, 91, and 105). Improvest was administered at 9 and 19 weeks of age (4 weeks pre-harvest). There was no diet × treatment × day (P > 0.78) nor diet × treatment (P > 0.11) interactions for any variables. Gilts had similar BWT, ADG, and ADFI until after the 2nd dose of Improvest, when Improvest-treated gilts were heavier (123.62 vs. 121.59 ± 0.68 and 138.16 vs. 133.97 ± 0.71 kg, days 91 and 105; P < 0.01), had increased ADG (1.19 vs. 1.09 ± 0.01 and 1.03 vs. 0.88 ± 0.02 kg/day days 91 and 105; P < 0.01) and consumed more feed (2.99 vs. 2.84 ± 0.03 and 3.19 vs. 2.68 ± 0.04 kg/pig/day; days 91 and 105; P < 0.01) compared with untreated gilts. Carcass evaluation was conducted on 120 pigs (2 pigs/60 pens). No significant structures were present on ovaries of Improvest-treated gilts. Improvest-treated gilts were heavier (market and HCW; P ≤ 0.02) than controls. Improvest-treated gilts tended (P ≤ 0.08) to have heavier bone-in butt and bone-in ham weights. Belly weights were heavier (kg and %HCW; P ≤ 0.05) in Improvest-treated vs control gilts and were thicker (P = 0.01) but were similar (P > 0.3) in length and width. While IV was similar (P > 0.2) in belly fat, loin intramuscular fat was increased (P < 0.01) from Improvest-treated gilts. Without additional dietary amino acids, Improvest-treated gilts delivered greater gain after the 2nd dose, yielding significantly heavier carcasses and primal cuts, including bellies which were larger as a percentage of HCW, and increased loin intramuscular fat.