The effect of propofol administered intravenously on appetite stimulation in dogs

Anorexia is defined as diminished appetite or aversion to food. Clinical ma nifestations of anorexia have multiple etiologies, which include systemic i llness, pain, fever, stress, metabolic disorders, and decreased palatabilit y and learned aversion to food, Disorders of appetite are common in compani on and laboratory animal medicine. Anecdotal evidence and personal experien ce suggest that propofol (2, 6-diisopropylphenol), when given intravenously at subhypnotic doses, causes acute appetite stimulation in dog, The establ ishment of a dose-response effect could have important clinical application s; therefore, this study attempts to qualify and quantify the effect of pro pofol on appetite stimulation in healthy young adult dogs. Six purpose-bred male dog (age, 6 months) were obtained from a Class A vendor, Dog were hou sed individually and provided water ad libitum throughout the study period, All dog were fed ad libitum to ensure that test conditions and degree of s atiety were identical. Each dog was assigned randomly to either an experime ntal group or control each day of the study, The experimental groups receiv ed single bolus intravenous injections of propofol at different dosage leve ls (0.5, 1.0, 1.5, 2.0, or 3.0 mg/kg of body weight), and the control group received saline. The administrator was blinded to the animal's identificat ion and dose. Dosages greater than 3.0 mg/kg resulted in profound sedation and ataxia, which physically inhibited the dogs from obtaining the food; th erefore 3.0 mg/kg was the highest dose tested, Dog were weighed daily to en sure accurate dosing. Dosing was performed at the same time each day to min imize variability, Food intake amounts were recorded at 15, 30, 60, 120, an d 1440 min after injection, Food intake was expressed as [food intake (g)/b odyweight (kg)/unit time (min)], After a 1-w rest period, the study was rep eated, Data were analyzed with a type RBF-65 randomized-block factoral desi gn (ANOVA), Each dog served as its own control. The two experiments were an alyzed separately, and a P-value of less than 0.05 was used to declare stat istical significance, A significant (P < 0.05) increase in food consumption was observed solely during the 0-to-15-min time interval; no significant i ncrease in food consumption was observed at any other time point. This data supports propofol's appetite stimulating effect in the initial 15 min afte r injection, Additional studies are required to explore the mechanism for t his effect and to determine whether it occurs in other species.