Another form of social facilitation in dogs relates to food preferences and selection. Although there are limited published data available, there is evidence that dogs are capable of learning preferences for novel flavors from other familiar dogs. ⁴ Dogs also react to human pointing gestures during food selection and some will even select a smaller quantity of food over a larger quantity if their owner directs more attention toward the smaller pile of food. ⁵ Given the large number of homes today that include more than one dog, the influence that the behavior of other dogs and of the owner may have upon an individual dog’s food choice is an important consideration.

Vestiges of the wolf’s food hoarding behaviors are often observed in domestic dogs. For example, some dogs frequently bury bones in their yard or hide coveted food items such as biscuits or chew bones in furniture or under beds. However, unlike their wild ancestors, many domestic dogs forget about outdoor hidden caches and rarely return to dig them up. Related activities that are common in dogs are scavenging and coprophagy (stool eating). ⁶ Many dogs readily consume garbage, carrion, insects, and feces that they encounter in the yard or while out walking. ^{7. and 8.} Plant eating, in particular grass eating, is also frequently reported by owners. Contrary to popular beliefs, there is no evidence that grass/plant eating in dogs is a sign either of illness or nutrient deficiency. ^{9. and 10.} Rather, grass eating appears to be a normal canid behavior as it is widespread among wolves and has not been shown to be associated with gastrointestinal upset or the onset of vomiting. ^{9. and 11.} It has been suggested that plant eating in canid and felid species may play a role similar to that described in chimpanzees, who consume entire leaves from various plants, which then function to purge intestinal parasites as they travel through the gastrointestinal tract. ^{10. and 12.} It is possible that plant eating evolved in dogs and cats to serve the same function. Although scavenging garbage and coprophagy are considered to be normal behaviors in dogs, these behaviors can present a health and sanitation risk and generally should be prevented. Keeping the yard picked up, using supervision, and teaching dogs a reliable “leave it” command are the best approaches to controlling scavenging and stool-eating behaviors.

The dog’s ancestry suggests that an intermittent feeding schedule consisting of large meals interrupted by periods of fasting is the most natural way to feed dogs. However, when dogs are given free access to food, they will consume many small meals frequently throughout the day. This pattern is similar to that seen in cats, with the exception that dogs tend to eat only during the daytime. ³ The domestic dog is quite capable of adapting to a number of different feeding regimens. These regimens include portion-controlled feeding, time-controlled feeding, or free-choice (ad libitum) feeding. These regimens, and the advantages and disadvantages of each, are discussed later in this chapter.