Research Programs Unit, Molecular Medicine, Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland.
PLoS One. 2012;7(7):e41684. doi: 10.1371/journal.pone.0041684. Epub 2012 Jul 26.
Obsessive Compulsive Disorder (OCD) is a neuropsychiatric disorder observed both in humans and animals. Examples of Canine Compulsive Disorder (CD) include excessive tail chasing (TC), light/shadow chasing and flank sucking. We performed a questionnaire survey to investigate the characteristics of compulsive (TC) and its possible associations with environmental correlates and personality in a pet population of 368 dogs from four dog breeds. We observed an early onset of TC at 3-6 months of age and a large variation in TC frequency in all breeds, with an overrepresentation of milder cases. Almost half of the TC dogs showed lowered responsiveness during bouts and displayed also other types of compulsions more often than the controls. Interestingly, dogs that received dietary supplements, especially vitamins and minerals, expressed less TC compared to dogs that did not receive any supplements. Neutered females had less TC, suggesting an influence of ovarian hormones on TC. Tail chasers were shyer and had separated earlier from their mothers than the controls. Finally, our genetic study did not find an association between TC and CDH2, a locus previously associated with the canine flank sucking compulsion. In conclusion, the early-onset and the variable nature of the repetitive behaviour, which is affected by environmental factors such as micronutrients, neutering and maternal care, share several similar components between canine and human compulsions and supports canine TC as a model for human OCD.
强迫症（OCD）是一种在人类和动物中都观察到的神经精神障碍。犬类强迫症（CD）的例子包括过度追逐尾巴（TC）、追逐光线/阴影和舔舐侧腹。我们进行了一项问卷调查，以调查宠物狗群中 368 只来自四个犬种的犬只强迫性（TC）的特征及其与环境相关性和个性的可能关联。我们观察到 TC 的发病年龄较早，在 3-6 个月时就出现，而且所有犬种的 TC 频率差异很大，轻度病例较多。几乎一半的 TC 犬在发作时反应能力下降，而且比对照组更常出现其他类型的强迫行为。有趣的是，与未服用任何补充剂的犬相比，服用膳食补充剂（尤其是维生素和矿物质）的 TC 犬表达较少。绝育的雌性犬 TC 较少，这表明卵巢激素对 TC 有影响。追逐尾巴的犬比对照组更胆小，更早与母亲分离。最后，我们的基因研究没有发现 TC 与 CDH2 之间的关联，CDH2 是先前与犬只舔舐侧腹强迫行为相关的基因座。总之，这种重复性行为的早期发病和多变性质，受环境因素如微量营养素、绝育和母婴护理的影响，与人类强迫症的犬类 TC 具有相似的成分，支持犬类 TC 作为人类 OCD 的模型。
