Dogs & Plants
Vegetation for canines can be controversial as the pet food industry has capitalized on the fact that dogs can consume plant matter leading to a carbohydrate-heavy norm. The spectrum for vegetation varies from raw feeders avoiding them at all costs to others using them as a source of essential nutrients. In the end, it comes down to quality and preparation. While canines can eat plants, they lack the physiology to fully digest plant matter, requiring some help from us to reap the full benefits. With appropriate selection and preparation, plants can add immense health benefits to every diet. So let's peel back the benefits of plants for our canine friends.
Lettuce Turnip The Beet
While dogs have no requirement for carbohydrates and much prefer meat, many canines happily gulp down a few berries - their ancestors do too!
A study by The Voyageurs Wolf Project revealed that during peak berry season (July-August), wolves (canine lupous) willingly consume berries and other wild fruits. While a method to precisely determine the consumption amount is yet discovered, in 10 wolves, an estimated 0.468 kg of berries were eaten.
But can modern canines digest plants? Yes and no.
Dogs are facultative carnivores, unlike cats and ferrets. Depending on the context, they will consume plant matter in response to their circumstance. While their diet should primarily be carnivorous, their food options are varied and include vegetation naturally, from gut content in wild prey to scavenging for berries. Their scavenging nature has made them savvy in surviving off anything.
But dogs have gotten at least 15,000 years for some evolutionary tuning, which often results in the “omnivore” title. Domestic dogs have more copies of the AMY2B gene (pancreatic amylase) than their ancestors. Other carnivores such as the wolf, coyote, and jackal have two copies of the AMY2B gene, whereas the modern dog has a spectrum from 2 genes (primitive breeds) up to 20.
Dogs can also convert beta-carotene to vitamin A (very poorly, I must say). They have evolved to choose the less desirable option of fresh meat and take the less taken path, including garbage, carcasses, plant matter, or anything edible. While dogs have evolutionary advantages in consuming starch, their otherwise carnivorous biology shows a carnivorous foraging lifestyle.
Vegetables and fruits are universally promoted as healthy. We, humans, are taught the benefits of consumption into adulthood. They have a high dietary place due to nutrients such as vitamin A, C, and minerals such as magnesium, phosphorus, and folic acid. While rich in many nutrients, relying on plants for a carnivore’s essential nutrients can be difficult.
This is due to animal nutrients being much more bioavailable than plants. For example, iron clearly distinguishes between heme and non-heme iron, but bioavailability and absorption are factors for all minerals. Each mineral has its own set of interactions with other nutrients. It has many different forms (including multiple organic and supplemental forms) and concentration considerations that affect how well the animal can use the nutrient. “The absorption and bioavailability of Fe in dogs can vary enormously, from close to 100% to less than 10%, depending on the ionic form of Fe in the diet, Fe status, dietary Fe concentration, and several other factors.” (NRC 2006). Dogs can also convert beta-carotene to vitamin A. However, as mentioned above, very poorly. The amount needed would be a great deal when vitamin A requirements could quickly be met with a small portion of liver.
While many formulations may use plants (especially wheatgrass) for the essential nutrients, I respectfully disagree that vegetables should be factored towards essential nutrients. I prefer to favor an animal counterpart if possible. Perhaps not the best source of certain essential nutrients, plants provide an unparallel source of antioxidants and phytonutrients, which we’ll discuss below.
Antioxidants reduce free radicals, a type of unstable molecule that may cause harm to healthy molecules. Free radicals are part of natural and healthy bodily functions but can be influenced by external factors and lifestyles and are hazardous in large amounts. The damage caused by free radicals harms healthy cells and the DNA, which can play a significant role in health conditions. Antioxidants can neutralize free radicals by donating an electron, combating their harmful effects. This helps break the chain reaction that can harm other cells. Antioxidants are the chill pill for free radicals.
Vitamin C, selenium, and carotenoids such as beta-carotene are specific antioxidants in vegetables and fruits. And recent data shows that vitamin K acts as an antioxidant by inhibiting ferroptosis cell death.
But one single antioxidant can’t single-handedly do everything. As variety is a vital pillar in raw feeding, so is variety in plants! Each antioxidant behaves differently. Therefore, a large variety of fruits and vegetables is key to getting an array of antioxidants, specifically phytonutrients.
Phytonutrients act as the front line of defense, protecting the plant from various stressors from pests, insects, and UV light (the sun). They also give plants their color, flavor, and aroma and are crucial non-nutritive compounds.
Each phytonutrient has unique properties, with more than 10,000 phytonutrients identified in edible plants. They include various chemicals from “carotenoids, indoles, glucosinolates, organosulfur compounds, phytosterols, polyphenols, and saponins.”
The different properties of phytonutrients allow them to aid in the roles of inflammation and oxidation. The amount of phytonutrients a plant contains depends on the food, origin, ripeness, farming practice, transportation, storage, and use. Many polyphenol supplements are out on the market, but they are less beneficial than phytonutrient-rich foods. As the concentration of phytonutrients varies, feeding the rainbow (aka variety) is a fail-proof way to deliver these potent compounds.
Fiber is classified as complex carbohydrates resistant to enzymatic digestion in the small intestine. As a result, the microbes in the colon ferment the fibers, which produce short chain fatty acids (SCFAs). SCFAs are the end products of fermentation of dietary fibers and have been found to increase gut resistance to pathogenic bacteria, increase the population of beneficial flora, and gut integrity, and may influence gut-brain communication.
In addition, all fiber holds some water which can aid in bulking the stool, which can be beneficial for dogs with difficulty expressing their glands. The gut microbiota also produces an array of compounds aside from SCFAs, such as the synthesis of vitamin K.
Want to hear more on the gut microbiome? Check out this episode of The Rawcast Podcast:
When To Be Cautious
There is no precaution to take in healthy dogs except prepping veggies and feeding in appropriate amounts. Anything in excess can cause problems, so feeding in moderate quantities and rotating foods is essential. But dogs with diagnosed health conditions must be cautious with their individual needs. The most important part is to do what is best for the individual dog. The most common health issues involving veggies are
Hypothyroid issues should avoid cruciferous vegetables.
Histamine sensitivities should avoid high histamine veggies.
Oxalate problems should avoid oxalate veggie.
And when in doubt, consult with your amazing veterinarian team.
Due to the cell wall, raw plant matter can be quite challenging for canines to digest. Thus, it is vital to prep the plant for maximum bioavailability. Breaking down plant matter before feeding allows for proper digestion. Optimal ways to do this are
What Preparation Method Should I Use?
More watery plant matter such as berries and cucumbers can be blended or mashed without cooking. However, less water-dense and starchier vegetables such as squash, beets, carrots, and sweet potatoes must be cooked via steaming or boiling to maximize absorption.
What plants should I use?
All plant matter used should be lower starch, lower-glycemic fruits & vegetables. A list of the most commonly used plant matter is below.
There is not a strict “dosage” for veggie mix. However, a loose guideline is outlined below.
1-2 tsp. small dogs
2-3 tsp. medium dogs
1-2 tbsp. large dogs
While not required for a balanced diet, plants are powerful in supplying fiber, phytonutrients, and probiotics when fermented. As long as it’s quality over quantity and prepared appropriately, vegetation is a smart addition to any diet. I hope you learned something new today & Always Keep Exploring!