Coprophagia (eating feces) is common in lagomorphs (rabbits) and rodents and has been observed in other species, including pigs, horses, and nonhuman primates. Domestic dogs are also prone to coprophagia-primarily eating their own feces-but the behavior is considered problematic in this species. The often-close bond between dogs and their owners also makes this behavior unhygienic. There is little information on the cause or treatment of coprophagia in dogs, but several explanations for the behavior have been proposed, including unbalanced diet, pancreatic enzyme deficiency, instinctive preference for decaying food, or inappropriate conditioning. It is believed that a diet rich in fat, protein, and fiber and low in carbohydrates may reduce the tendency, but no evidence to support this assertion has been found. Thus, the behavior may have a learned component. In this study, 28 Labrador retrievers (both male and female) with the behavior were divided into 2 groups to compare the effectiveness of 2 treatments: a remote spray collar (citronella) and a loud noise (remote horn). Severity of the behavior pattern was evaluated by the owners before the study began, during treatment, and 1 week after treatment was stopped.

Both treatments resulted in significantly lower incidence of the behavior in the first week, but the dogs treated with sound therapy slowly reverted to the original pattern of coprophagia. However, the problem continued to decrease during the 3-week treatment period in the dogs treated with the spray collar, and the incidence of coprophagia remained unchanged during the follow-up week without treatment and was much lower than before treatment began. It has been suggested that both treatments function as disruptive stimuli, but the spray collar targets the senses of smell, hearing, and touch while the sound therapy targets only hearing. An odorless spray collar that is equally effective in disrupting unwanted behavior is also available. The effectiveness of more traditional treatment programs, such as dietary changes or counterconditioning, remains unknown.

COMMENTARY: Coprophagia is a relatively common behavioral problem in dogs and a source of frustration for both veterinarians and their clients. The problem has received little objective assessment and as a result, a variety of remedies has been used, none of which appears to be particularly effective. This paper shows that a citronella spray collar reduces the frequency of coprophagia in dogs and that this effect persists after treatment has ceased. The technique needs direct owner observation and participation, and the posttreatment follow-up period in the study was short. Nevertheless, the technique shows promise in negating this behavior.

Comparison of two treatments for preventing dogs eating their own faeces. Wells DL. VET REC 153:51-53, 2003.