Some dogs are notorious for devouring almost any food put before them, but if you’ve tried without success to feed fruit to your dog, you may answer “no” to the above question. It turns out that personal preference doesn’t come close to settling the issue, however.
Whether or not fruits and vegetables are a natural part of the canine diet remains a bone of contention among raw and home-feeding dog owners.
Recent studies on the wolf, the closest living relative of todays domestic dog, are shedding new light on the subject. Using telemetry (satellite guided tracking), wolves can be followed so closely that researchers can study exactly what they eat and when. One study, Foraging and Feeding Ecology of the Gray Wolf, by Daniel R. Stahler, Douglas W. Smith and Debra S. Guernsey tracked the eating habits of wolves in Yellowstone National Park. Preliminary evidence suggests that kill rates decrease as much as 25% in summer, when fruit and other plant foods are available. Further studies exploring seasonal changes in wolf predation are still underway.
Yellowstone wolves tend to be more selective than wolves inhabiting areas with more natural predator-to-prey ratios. Nevertheless, they sometimes went without fresh meat for up to several weeks, according to the study. In summer, fruit was available to fill in the gaps, but in winter they subsisted by scavenging carcasses consisting mostly of bone and hide.
Although it differs by continent, studies on wolf scats have shown evidence that wolves commonly eat a wide variety of fruits, including berries, cherries, apples, pears, figs and grapes. Yes, grapes! (See my previous blog articles about the grape “controversy“)
The dietary classification for dogs usually boils down to the question: Omnivore or carnivore? Actually, both are correct. Dogs belong to a class of species called facultative carnivora, meaning that they have all the faculties of a carnivore, but are able to survive on foods other than prey, when necessary, for extended periods. In practical terms, this classification is not distinguishable in any meaningful way from omnivorism.
While fruits seem to be a natural variable in the canine diet, the same cannot be said for vegetables, as a whole. The difference is digestibility. The nutrients in vegetables are encased in a tough cellulose membrane and require the kind of teeth that can chew and grind them. Dogs aren’t equipped with these, and they lack the digestive enzymes that would do the trick in lieu of chewing. The only possible exception to this is some starchy vegetables, which resemble overripe fruit in composition when they are cooked. Examples would be yams, sweet potatoes, squash and pumpkin.
There is no doubt that prey has been the main preferred food source for dogs throughout their biological history. However, scarcity of prey has featured prominently enough to hold important clues for modern dog owners seeking to feed their pets properly. If we want to truly replicate nature, we have to feed prey foods only as frequently as dogs have historically had access to them, on average. Lacking that precise data, all we can do is estimate a range, based on the evidence. The frequency end of the spectrum will be easier to pin down than the infrequency end, since the latter is based on fragmented information and will represent the elusive mean average of all those occasions when dogs experienced prey scarcity. Giving great consideration to widely varying individual factors like size, condition and activity level of the dog being fed, optimal is likely somewhere between 2-4 times weekly to a few times per month.
Wolves have been known to go as long as 6 months without a kill. This is probably rare, admittedly, but it would be just as uncommon for a wolf to eat his fill of prey everyday for days and months on end, like many domestic dogs do. And it must be noted that wolves are extremely physically active, unlike most domestic dogs.
Domestic dogs that are fed prey foods too regularly are often overweight, sluggish, and symptomatic in one way or another. This is true regardless of whether the food is raw or cooked, commercial or home prepared, although dogs fed a homemade raw diet will have far fewer health problems, of course. Often, these dogs will not eat fruit. There is no reason for a dog to eat a secondary food like fruit if primary foods are fed with such regularity as to produce the conditioned expectation of getting them. When owners switch to feeding prey foods on a more infrequent or random basis, and particularly if appropriate fasting days are thrown in, they often find that their dogs will eat fruits readily even though they shunned them before.
When this kind of rotational feeding plan is implemented, owners almost always see positive changes in their dogs as well, like increased energy, shinier coat, better digestion and symptom cessation, especially if only one type of food is fed per day (as opposed to mixing foods together, which complicates digestion) and the foods are raw and biologically appropriate.
Feeding fruit regularly is beneficial not only because it simulates the gaps in primary food availability that a dog would experience in nature, but for what fruits don’t contain: namely, excess fat, stored toxins, nutrient imbalances, etc. Even when dogs are raw-fed, the foods that are produced in the modern meat industry can’t ideally meet their nutritional needs because they don’t precisely resemble what wild dogs have eaten throughout their history. For example, humans have developed methods that produce food animals with a higher than natural ratio of muscle to bone. Wild birds that are capable of flying hundreds of miles have tiny breast muscles, while modern domestic poultry that can’t fly at all have huge mutated chests that are only good for one thing – feeding humans. These manipulations create nutritional excesses or imbalances in those who eat them, even when the consumer is a carnivore.
In addition, producers often feed indigestible, inappropriate foods and toxic substances that get stored in food animals fatty tissues and cause problems when eaten by dogs. There are other problems, too, like the lack of freshness, unavailability of whole animals and finding food animals with bones that are small enough to either be ground or chewed and consumed by small or medium-sized dogs. Dogs need the entire bodies of prey, not just muscle meat.
So for civilized dogs, fruit represents a valuable break from the excesses inherent in modern foodstuffs. Fruit, in fact, is so easy for a dog’s body to break down that a day of only fruit allows almost as much rest for the digestive tract as a fasting day. And with modern dog owners being as reluctant as they typically are to employ the crucial ‘famine’ part of the natural feast-and-famine cycle that dogs are adapted to, fruit can provide the emotional satisfaction of feeding while allowing digestive rest at the same time.
The idea that plant foods actually represent a larger proportion of a dog’s natural diet than previously supposed would explain the anecdotal success that some people are enjoying raising vegan and vegetarian dogs, as well. For dog owners wanting to minimize the use of animal products for ethical, ecological or financial reasons, feeding meat less frequently in favor of fruit and other appropriate plant fare offers this opportunity while not compromising the health of the dog. Even if owners are not constrained by such concerns and wish only to keep their dogs in optimal health, fruit can be an important piece of the puzzle.