TY - JOUR T1 - STUDIES OF CHRONIC MORPHINE POISONING TN DOGS I. GENERAL SYMPTOMS AND BEHAVIOR DURING ADDICTION AND WITHDRAWAL JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 329 LP - 357 VL - 33 IS - 3 AU - O. H. PLANT AU - I. H. PIERCE Y1 - 1928/07/01 UR - http://jpet.aspetjournals.org/content/33/3/329.abstract N2 - Symptoms and behavior are recorded in twenty-four addictions to morphine and in twenty-two withdrawals in dogs, in which detailed observations were made over periods covering from forty to three hundred and thirty days and with doses of 30 to 230 mgm. per kilogram. Considerable variability in symptoms during chronic poisoning with morphine was observed. The severity of withdrawal symptoms varied markedly in different dogs. These differences are not related to length of addiction or size of dose at withdrawal. Two dogs showed very severe symptoms during withdrawal and in both of these the dose was relatively small. Two animals died in addiction during administration of large doses. One died on the third day of withdrawal. When the symptoms observed in this group of dogs are considered as a whole they form a composite picture that is strikingly similar to that obtained in chronic morphine poisoning in man; this is particularly true of withdrawal symptoms. We believe that the observations reported in this paper show there is marked similarity between morphine addiction and withdrawal in man and in dogs; that this similarity makes the dog a particularly suitable test object for the study of many phases of the morphine problem; that results obtained in experiments on dogs can be applied to the problems of morphine addiction with greater validity than those on any other laboratory animal. ER -