RESEARCH Puppy behavior when left home alone: Changes during the first few months after adoption Simona Cannas, DVM a , Diane Frank, DVM, DACVB b , Michela Minero, DVM, PhD, ECVBM-CA a , Martin Godbout, DVM, MSc, DACVB c , Clara Palestrini, DVM, PhD, ECVBM-CA a a Dipartimento di Scienze Animali, Sezione di Zootecnica Veterinaria, Facolta ` di Medicina Veterinaria, Universita ` degli Studi di Milano, Milano, Italy; b Universite ´ de Montre ´al, Faculte ´ de Me ´decine Ve ´te ´rinaire, Centre Hospitalier Universitaire Ve ´te ´rinaire, Saint-Hyacinthe, QC, Canada; and c Ho ˆpital ve ´te ´rinaire de Loretteville, Groupe ve ´te ´rinaire Daubigny, Que ´bec, QC, Canada. KEYWORDS: puppy; dog; behavior; puppy development; separation anxiety Abstract Limited data are currently available describing normal behaviors of puppies left alone or on actual age of onset of separation-related problems. This study aims to describe variability and temporal distribution of puppy behavior when home alone during the first few months following adoption. Thirty-two puppies, ranging in age from 50 to 118 days, were filmed when home alone for 60 minutes. The videotaping was repeated again after 1 and 2 months, for a total of 3 observations per puppy. Information on physical and social environment and history of the puppy were collected. Fourteen be- havioral categories were established to describe duration and frequency of puppy activity. Descriptive analysis, principal component analysis, and general linear model repeated measures were performed. Puppies spent most of their time exhibiting passive behavior (40.38 6 18.31 minutes) as opposed to being oriented to the environment (OE) (4.5 6 5.06 minutes). Puppies played (6.1 6 9.53 minutes) and vocalized (VO) (2.7 6 6.25 min) while separated from their owners. Locomotion, exploration, oral behavior (OB), and grooming were observed for short periods. Puppies in the first film tended to be less active (LO 5 0.44 6 1.07 minutes; OE 5 3.37 6 3.59 minutes) than in the third one (LO 5 1.09 6 2.02 minutes; OE 5 5.23 6 5.53 minutes). Only 3 puppies out of 32 were character- ized by stress-related behaviors such as lip licking, VO, and OB. These behaviors decreased over time, with mean duration for OB and VO in film 1 at 143 6 184 seconds and 1341 6 1331 seconds, respec- tively, and at 0 6 0 seconds, and 46 6 80 seconds in film 3. The mean frequency of lip licking during the first film was 11 6 16 and in the third was 1 6 1. The results of this study show that even if some puppies showed stress-related behaviors, these behaviors did not persist over time. Ó 2010 Elsevier Inc. All rights reserved. Introduction Knowledge of normal canine behavior and its development is important not only for the understanding and treatment of canine behavior problems, but also for prevention Address for reprint requests and correspondence: Simona Cannas, Di- partimento di Scienze Animali, Sezione di Zootecnica Veterinaria Facolta ` di Medicina Veterinaria, Universita ` degli Studi di Milano, Via Celoria 10, 20133, Milano, Italy; Phone: 139 02 50318049; Fax: 139 02 50318030. E-mail: simona.cannas@unimi.it 1558-7878/$ -see front matter Ó 2010 Elsevier Inc. All rights reserved. doi:10.1016/j.jveb.2009.08.009 Journal of Veterinary Behavior (2010) 5, 94-100