Subscribe to petMD Blogs

Never miss a single post!

Fully Vetted
The Daily Vet
Nutrition Nuggets
Purely Puppy
Healthy Assurance
The Daily Vet is a blog featuring veterinarians from all walks of life. Every week they will tackle entertaining, interesting, and sometimes difficult topics in the world of animal medicine – all in the hopes that their unique insights and personal experiences will help you to understand your pets.

Genetics Markers Prove Dogs Have Evolved to Digest Carbohydrates and Starches

PrintPrint

January 29, 2013 / (17) comments

One could spend all day, or more, engaging in (sometimes heated) dialogue about what our pets should eat. Depending on your personal beliefs, education, and experience, your perspective could be vastly different from another pet owner. Even within the veterinary community, there are a wide range of recommendations as to what is the most appropriate style of feeding for our companion canines and felines.

 

Should your pet eat a whole-food based diet made up of nutrients identical or similar to the form created by nature, or a highly processed diet engineered into a dehydrated (and seemingly devitalized) piece of kibble?

What about the components that make up a particular diet? Should pet food have whole meats, vegetables, fruits, and grains? Or is it sufficient to feed protein and grain meals and by-products that have been coated with rendered fat and infused with artificial colors to increase palatability and appeal to owner aesthetics (respectively)?

Should you be feeding grains and starches to your pooch? Can dogs even digest them? Recently, a study published in Nature magazine proved that dogs’ domestication complements environmental and geographical changes associated with their role as companions to humans. It’s proven in their genes, which have evolved similarly to man’s and reflect dogs’ ability to digest grains and starches.

The authors of the study, titled The Genomic Signature of Dog Domestication Reveals Adaptation to a Starch-Rich Diet, conducted "whole-genome resequencing of dogs and wolves to identify 3.8 million genetic variants used to identify 36 genomic regions that probably represent targets for selection during dog domestication. Nineteen of these regions contain genes important in brain function, eight of which belong to nervous system development pathways and potentially underlie behavioral changes central to dog domestication.

“Ten genes with key roles in starch digestion and fat metabolism also show signals of selection. We identify candidate mutations in key genes and provide functional support for an increased starch digestion in dogs relative to wolves. Our results indicate that novel adaptations allowing the early ancestors of modern dogs to thrive on a diet rich in starch, relative to the carnivorous diet of wolves, constituted a crucial step in the early domestication of dogs."

As domesticated dogs are believed to have evolved from wolves nearly 11,000 years ago, their evolutionary process parallels a similar genetic shift seen in humans. Today’s dogs and humans eat and can digest a wider variety of foods in comparison to the primarily meat protein meals that were hunted, killed, or scavenged by their lupine and Cro-Magnon predecessors.

To fit modern times, we should be providing our canine companions some variety in their diets. I am an advocate of both dogs and cats eating whole food meals instead of processed diets. As ChooseMyPlate.gov does not advocate that we humans regularly eat highly processed foods, the same basic principles should apply to our canine and feline companions.

Even though today’s dogs can digest grains and starches, I don’t recommend that such nutrients form the majority of a dog’s diet. Any grains or starches made to be consumed by our pets should be whole-food based, cooked, and included in a small to moderate quantity (30% or less of the volume of a particular meal), complementing the larger percentage of meat, vegetable, and fruit ingredients.

Although commercially available and home prepared diets that are 100 percent free of grains and starches are popular, there are nutritional benefits stemming from their inclusion. Whole grains like brown rice, barley, etc., are good sources of minerals (Selenium, Manganese, etc.) and can even serve as substrates (pre-biotics) on which beneficial bacteria (pro-biotics) grow. Starches like russet and sweet potatoes, banana, etc., are rich in vitamins (A, B6, E, etc.) and minerals (Potassium, Manganese, etc.).

Part of where my concern about pets eating commercially available pet foods containing grains and starches lies in the quality of the ingredients. The majority of canine and feline diets are made with ingredients that are "feed-grade," which are of lower quality than "human-grade" and have higher potential to contain unhealthy substances (e.g., deoxynivalenol [vomitoxin], aflatoxin, etc.) according to the FDA Regulatory Guidance for Toxins and Contaminants.

Short or long term consumption of these toxins can cause inflammatory bowel disease, kidney and liver damage, or even cancer (see petMD article: Are You Poisoning Your Companion Animal by Feeding 'Feed-Grade' Foods?).

How you feed your pet is your personal choice. Nobody can force you to feed a particular commercially available or home prepared option. My best suggestion is to model your pet’s diet after that which humans are recommended to eat, which means choosing a variety of whole foods and minimizing processed foods.

What’s your perspective on how our companion canines (and felines) should eat?

 

 

Dr. Patrick Mahaney

 

 

Image: Chopstick Joe - Joe eating rice by Nicole Hanusek / via Flickr

 

Subscribe to The Daily Vet
COMMENTS (17)
1
Your article
by Martingudell on 01/29/2013 05:19am

Thank you Doctor for great article on dog feeding. I have carefully read what you wrote, and amazingly is the kind of diet I always provide my two dogs (Astor & Callas) with. It was a very helpful one, indeed!. greatings of a daily reader, from Argentina. Martin.

by Dr. Patrick Mahaney on 02/06/2013 01:06am

Thank you for your comments. Greetings from California! It's great to learn that we have PetMD readers in Argentina (a place I've always wanted to go).
From my clinical experience, I've recognized the importance of feeding whole food based diets to our pets instead of processed food; especially considering the mild to severe and potentially irreversible diseases (obesity, diabetes, cancer, etc.) that are occurring in increased frequency as a result of consumption of processed foods made with feed-grade ingredients.
I hope to see you back again on my PetMD page.
Dr. PM
www.PatrickMahaney.com

2
Dogs have evolved ... .
by KatsKat on 01/29/2013 05:38am

first of all, I'd love to know who paid for this 'study'... and Secondly, I will continue to provide my dogs, and my family as 'species appropriate' diet as I can afford. And for the dogs, that does not include potatoes or pasta - other than perhaps as a 'treat'. Only in very recent years have potatos, rye, tapioca, peanut hulls, and other , IMPO, waste products been included in pet foods as supposed 'nutritional' benefit. Raw ( for my animal ) meats, eggs, bones, fresh green leafy vegetables, some fruit will continue to make up the mainstay of their daily diets. They do not get a 'grain' or 'carb' free diet, but what I do add is in appropriate quantities, 'pre-digested' (steamed/cooked/mashed) and not as the 'base' of their diets.

by Dr. Patrick Mahaney on 02/06/2013 01:07am

Thank you for your comments.
It's great to hear that you are providing your pet with dietary variety and whole foods.
Dr. PM

3
It "proves" nothing
by Rod Russell on 01/29/2013 09:01am

The article proves nothing. It is some evidence in one direction, while there remains a lot more evidence in the opposite direction. If dogs have "evolved" away from meat, then why do other studies show that feral dogs prefer killing and eating small animals over nibbling on foliage? And, why do other studies show that wolves will also eat fruits, grains, and greens?

by Dr. Patrick Mahaney on 02/06/2013 01:10am

To say that my article or the Nature-published study "proves nothing" is a gross understatement. The well-thought out study indicates that dogs are capable of digesting a variety of foods, which is the manner by which we should feed them (real food, minimally processed, etc.) even if it is less convenient or costs more to do so.
Dr. PM

by Westcoastsyrinx on 02/06/2013 01:34am

So very true, Dr Mahaney. Just take a dog for a walk in an area where crows may have dropped chicken bones out of garbage cans, as an example. Dogs are scavengers and will eat pretty well anything. They are lucky we are around to keep their diet nutritious and save them from brittle bones at times, just for starters.

by Rod Russell on 02/06/2013 07:14am

Doctor, you apparently do not know the difference between "proof" and "evidence". The article's evidence is contradicted by evidence in other articles, and therefore it's contention is not proved, at all. And because of those contradictions of evidence, the article's conclusion overreaches the limits of its own evidence.

4
Derisive comments above
by Westcoastsyrinx on 01/29/2013 02:42pm

While the detractors of science who prefer to put their faith in the 'dog'ma that has no data to back it, they can easily find the source of funding for the study being discussed if they pay the fee to purchase it at http://www.nature.com/nature/journal/vaop/ncurrent/full/nature11837.html. All they need to do is click on the "Affiliations" tab at the website, but maybe the question of funding has come about because the writers aren't trained to read good research abstracts?

All living things are continuously evolving genetically and those who don't understand this clearly are lacking in education, as well as observational skills.

As Dr Mahaney points out, both nutrient variety and good quality ingredients are important. In particular the mention of whole grain rice means a supply the best form of substrate for the gut to get the most out of what is eaten. The study proving gut flora information also mentions beet pulp which is often found in commercial pet foods. Since reading the data attached to the 1999 Buddington study I have had no qualms when it comes to the feeding SOME good quality plant sources of nutrients, both for cats and dogs as that data also proves an acceptance of plant materials, (http://www.ncbi.nlm.nih.gov/pubmed/10188819).

Dogs have not "evolved away from meat", they just manage to live MUCH longer on a more varied supply of nutrients these days. Much of what our pets see as food in today's world depends upon what they were taught as pups to eat by the adults, and/or owners.

Personally I would never take in a dog that needed to eat raw meat as I wouldn't want the children in my home to be handling the pets, and I wouldn't want to have to deal with the shorten life span coming from a high cholesterol diet.

by Rod Russell on 01/29/2013 07:34pm

As usual, westie, when you have nothing of value to offer, you attack the messengers and deny their evidence. Denial & attack, denial & attack. Your M.O. is like a tattoo on your forehead.

by Dr. Patrick Mahaney on 02/06/2013 01:13am

Thank you for your insightful comments and willingness to do extra research in including hyperlinks to information that backs up your statements.
Your clear thinking and reasonable approach to the (obviously) controversial topic of what pets should/not eat provides a nice contrast to other comments on this article.
Dr. PM

5
Why is food so emotional?
by Lucy G. on 01/29/2013 02:55pm

I do not understand why food has become such a horribly emotional subject. I have always been quite fit; I (and my sheltie!) exercise every day. I try to eat well and feed him well but I also have very healthy friends with healthy dogs, that do not do just as I do.

For me, I stick to low-fat, partial vegetarian (I do eat fish) and mostly whole grains. I do eat some sweets, in small, planned-for portions. My favorite lunch is a whole-wheat english muffin with peanut butter and an apple. My dog is always happy to have a taste of both. :-) Breakfast may be raisin toast and an ounce of lowfat cheese and I make home-cooked meals for myself and my husband. I always use whole grain pasta and mostly whole grain bread or tortillas for myself. I generally have to provide my husband with a different bread and forget brown rice for him!

My doggie gets small portions at his meals. He gets chicken, turkey or fish (I do cook it for him...feels safer to me) pumpkin or sweet potato, yogurt and frozen green beans. I give him a half-teaspoon of salmon oil 3 or 4 times a week. I use a high-quality kibble for training treats...right now he favors salmon and garbanzo bean from Artemis OSOPURE. I also bake him doggie cookies, usually peanut butter or pumpkin, for a special reward. He also enjoys sharing whatever I have. :-)

I am 51, still a size 4 or 6. I am very strong in the gym and can out-hike most young people. My sheltie is also a good, little hiker. To be honest, I believe that exercise is the real key to good health. You can eat a perfect diet and still be weak and flabby. Even if you are not always perfect in your eating habits, exercise will make you stronger and healthier.

I have many friends who feed raw diets to their dogs. I dog-sit for people who feed raw. The dogs are healthy. Most people who feed kibble-based diets that I know add some extra goodies and their dogs are also healthy.

The vet here has suggested a good way to feed. I did not think she was insisting anyone do what she said...it was a suggestion. I feed my sheltie much the way she describes and he is very fit and healthy. That does not mean there are not other ways to do it.

It is the same for people. There are many healthy ways to eat. The most important thing though, is get away from the computer and go get some exercise.

by Dr. Patrick Mahaney on 02/06/2013 01:16am

Thank you for your comments.
I appreciate hearing how you take care of yourself through a healthful/whole food diet and exercise, then apply similar principles to your dog. Those of us living a lifestyle which focuses first on health through good habits understand the value of real-food based nutrients that are minimally processed as a means of providing nutrition that processed food cannot energetically equal.
I hope you and your pet have many years of good health ahead of you!
I hope to see you back again on my PetMD Daily Vet page.
Dr. PM
www.PatrickMahaney.com

6
Quality
by TheOldBroad on 01/29/2013 06:17pm

"lies in the quality of the ingredients"

In my opinion, that's true for starches as well as animal-based protein. We've all heard the urban story about the people that were sitting in a popular fast-food restaurant and noticed a meat delivery with the boxes labeled, "Fit For Human Consumption."

If there's any truth to the story at all, I'm not sure I'd be eating there again any time soon.

by Dr. Patrick Mahaney on 02/06/2013 01:18am

YES!
Great story. I hope it's not just an urban myth.
I'd love to see a photo of the "fit for human consumption" sign. Perhaps you know someone who frequents fast food restaurants that can snap a shot!
Thank you for your comments.
Dr. PM

by TheOldBroad on 02/06/2013 03:58am

As expected, this is an urban story. Snopes.Com:

http://www.snopes.com/food/prepare/badmeat.asp

by TheOldBroad on 02/06/2013 04:00am

Please note that the whole URL did not post. If anyone uses it, please add ".asp" at the end.

LEAVE COMMENTS

Connect with Facebook or login to leave comments.

 



MEET THE VETS

Lorie Huston, DVM is a small animal veterinarian with over 20 years experience...
READ MORE

Patrick Mahaney, VMD is an integrative veterinarian who combines western and eastern perspectives...
READ MORE

Ken Tudor, DVM has a veterinary practice focused exclusively on pet weight loss and management...
READ MORE

Anna O'Brien, DVM is a large animal veterinarian working just outside of Washington, D.C. in Maryland...
READ MORE

Dr. Joanne Intile, DVM, DACVIM is a Cornell trained veterinary oncologist practicing in Maryland…
READ MORE

  • Lifetime Credits:
  • Today's Credits:
Hurry Before All Seats are Taken!
Enroll
Be an A++ Pet Parent! Take fun & free courses to earn badges & certifications. Choose a course»
Subscribe to The Daily Vet

Most Read Daily Vet Articles

Lyme Disease: The Tragic Effects on Our Pets ...
Having been in veterinary practice on both the East and West coasts, Dr. Patrick...
READ MORE
Paraphimosis: Pet Emergency or Owner ...
Dr. Patrick Mahaney recently got a picture text from worried a client that made him...
READ MORE
Preventable Illnesses on the Rise for Cats
Veterinarians have a wide variety of technology that can detect many diseases early,...
READ MORE
Top Five Dog Bite Prevention Tips
For National Dog Bite Prevention Week, Dr. Mahaney shares his top 5 methods for avoiding...
READ MORE

Most Commented Articles

Vaccination Opt Out Letters
It has become more common for owners to request that veterinarians write letters...
READ MORE
Top Five Dog Bite Prevention Tips
For National Dog Bite Prevention Week, Dr. Mahaney shares his top 5 methods for avoiding...
READ MORE
Balanced Homemade Meals – I Sound Like a ...
This week Dr. Ken Tudor reports on the results of a recent study on homemade pet...
READ MORE
Paraphimosis: Pet Emergency or Owner ...
Dr. Patrick Mahaney recently got a picture text from worried a client that made him...
READ MORE

PETMD POLL

What do you use to prevent ticks from feeding on your pet?

Spot-on meds
60% (134 votes)
Oral meds
14% (32 votes)
Tick collars
7% (16 votes)
Other
6% (13 votes)
N/A (I do not use tick preventives)
12% (27 votes)
Total votes: 222

Subscribe to petMD Blogs

Never miss a single post!

Fully Vetted
The Daily Vet
Nutrition Nuggets
Purely Puppy
Healthy Assurance


MORE FROM PETMD.COM