Natural Balance Ultra (Dry)

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Rating: ★★★½☆

Natural Balance Ultra Dog Food earns the Advisor’s mid-tier rating of 3.5 stars.

The Natural Balance Ultra product line lists three dry dog foods, two claimed to meet AAFCO nutrient profiles for all life stages and one for adult maintenance.

The following is a list of recipes available at the time of this review.

  • Natural Balance Original Ultra Formula
  • Natural Balance Original Ultra Small Breed Bites
  • Natural Balance Original Ultra Reduced Calorie (2.5 stars)

Natural Balance Original Ultra was selected to represent the other products in the line for this review.

Natural Balance Original Ultra

Dry Dog Food

Estimated Dry Matter Nutrient Content

Protein = 26% | Fat = 14% | Carbs = 52%

Ingredients: Chicken, brown rice, lamb meal, oatmeal, barley, potatoes, carrots, duck meal, chicken fat (preserved with natural mixed tocopherols), tomato pomace, natural flavor, canola oil, brewers yeast, duck, salmon meal, sodium chloride, potassium chloride, salmon oil, whole ground flaxseed, choline chloride, taurine, natural mixed tocopherols, spinach, parsley flakes, cranberries, l-lysine, l-carnitine, Yucca schidigera extract, dried kelp, vitamin E supplement, iron proteinate, zinc proteinate, copper proteinate, ferrous sulfate, zinc sulfate, copper sulfate, potassium iodide, thiamine mononitrate (vitamin B1), manganese proteinate, manganous oxide, ascorbic acid, vitamin A supplement, biotin, niacin, calcium pantothenate, manganese sulfate, sodium selenite, pyridoxine hydrochloride (vitamin B6), vitamin B12 supplement, riboflavin (vitamin B2), vitamin D3 supplement, folic acid

Fiber (estimated dry matter content) = 3.3%

Red items when present indicate controversial ingredients

Estimated Nutrient Content
MethodProteinFatCarbs
Guaranteed Analysis23%13%NA
Dry Matter Basis26%14%52%
Calorie Weighted Basis23%31%46%

The first ingredient in this dog food is chicken. Although it is a quality item, raw chicken contains about 80% water. After cooking, most of that moisture is lost, reducing the meat content to just a fraction of its original weight.

After processing, this item would probably account for a smaller part of the total content of the finished product.

The second ingredient is brown rice, a complex carbohydrate that (once cooked) can be fairly easy to digest. However, aside from its natural energy content, rice is of only modest nutritional value to a dog.

The third ingredient includes lamb meal. Lamb meal is considered a meat concentrate and contains nearly 300% more protein than fresh lamb.

The fourth ingredient is oatmeal, a whole-grain product made from coarsely ground oats. Oatmeal is naturally rich in B-vitamins, dietary fiber and can be (depending upon its level of purity) gluten-free.

The fifth ingredient lists barley. Barley is a starchy carbohydrate supplying fiber and other healthy nutrients. Unlike grains with a higher glycemic index, barley can help support more stable blood sugar levels.

The sixth ingredient is potato. Potatoes can be considered a gluten-free source of digestible carbohydrates. Yet with the exception of perhaps their caloric content, potatoes are of only modest nutritional value to a dog.

The seventh ingredient includes carrots. Carrots are rich in beta-carotene, minerals and dietary fiber.

The eighth ingredient includes duck meal, another protein-rich meat concentrate.

The ninth ingredient is chicken fat. Chicken fat is obtained from rendering chicken, a process similar to making soup in which the fat itself is skimmed from the surface of the liquid.

Chicken fat is high in linoleic acid, an omega-6 fatty acid essential for life. Although it doesn’t sound very appetizing, chicken fat is actually a quality ingredient.

The tenth ingredient is tomato pomace. Tomato pomace is a controversial ingredient, a by-product remaining after processing tomatoes into juice, soup and ketchup.

Many praise tomato pomace for its high fiber and nutrient content, while others scorn it as an inexpensive pet food filler.

Just the same, there’s probably not enough tomato pomace here to make much of a difference.

From here, the list goes on to include a number of other items.

But to be realistic, ingredients located this far down the list (other than nutritional supplements) are not likely to affect the overall rating of this product.

With six notable exceptions

First, we note the inclusion of canola oil. Unfortunately, canola can be a controversial item. That’s because some worry that canola oil is made from rapeseed, a genetically modified (GMO) raw material.

Yet others cite the fact canola oil can be a significant source of essential omega-3 fatty acids.

In any case, plant-based oils like canola are less biologically available to a dog than fish oil as a source of quality omega-3 fats.

Next, brewers yeast can be a controversial item. Although it’s a by-product of the beer making process, this ingredient is rich in minerals and other healthy nutrients.

Fans believe yeast repels fleas and supports the immune system.

Critics argue yeast ingredients can be linked to allergies. This may be true, but (like all allergies) only if your particular dog is allergic to the yeast itself.

In addition, a vocal minority insists yeast can increase the risk of developing the life-threatening condition known as bloat. However, this is a claim we’ve not been able to scientifically verify.

In any case, unless your dog is specifically allergic to it, yeast can still be considered a nutritious additive.

What’s more noteworthy here is that brewers yeast contains about 48% protein, a factor that must be considered when judging the actual meat content of this dog food.

In addition, salmon oil is naturally rich in the prized EPA and DHA type of omega-3 fatty acids. These two high quality fats boast the highest bio-availability to dogs and humans.

Depending on its level of freshness and purity, salmon oil should be considered a commendable addition.

We also note the inclusion of flaxseed, one of the best plant sources of healthy omega-3 fatty acids. Provided they’ve first been ground into a meal, flax seeds are also rich in soluble fiber.

However, flaxseed contains about 19% protein, a factor that must be considered when judging the actual meat content of this dog food.

Next, we find no mention of probiotics, friendly bacteria applied to the surface of the kibble after processing to help with digestion.

And lastly, this food also contains chelated minerals, minerals that have been chemically attached to protein. This makes them easier to absorb. Chelated minerals are usually found in better dog foods.

Natural Balance Ultra Dog Food
The Bottom Line

Judging by its ingredients alone, Natural Balance Ultra looks like an above-average dry dog food.

But ingredient quality by itself cannot tell the whole story. We still need to estimate the product’s meat content before determining a final rating.

The dashboard displays a dry matter protein reading of 26%, a fat level of 14% and estimated carbohydrates of about 52%.

As a group, the brand features an average protein content of 24% and a mean fat level of 13%. Together, these figures suggest a carbohydrate content of 56% for the overall product line.

And a fat-to-protein ratio of about 53%.

Below-average protein. Below-average fat. And above-average carbs when compared to a typical dry dog food.

Even if you ignore the protein-boosting effect of the brewers yeast and flaxseed, this still looks like the profile of a kibble containing a moderate amount of meat.

Bottom line?

Natural Balance Ultra is a plant-based dry dog food using a moderate amount of chicken or lamb meals as its main sources of animal protein, thus earning the brand 3.5 stars.

Recommended.

Please note certain recipes are sometimes given a higher or lower rating based upon our estimate of their total meat content and (when appropriate) their fat-to-protein ratios.

Special Alert

Rice ingredients can sometimes contain arsenic. Until the US FDA establishes safe upper levels for arsenic content, pet owners may wish to limit the total amount of rice fed in a dog's daily diet.

A Final Word

The descriptions and analyses expressed in this and every article on this website represent the views and opinions of the author.

Although it's our goal to ensure all the information on this website is correct, we cannot guarantee its completeness or its accuracy; nor can we commit to ensuring all the material is kept up-to-date on a daily basis.

Each review is offered in good faith and has been designed to help you make a more informed decision when buying dog food.

However, due to the biological uniqueness of every animal, none of our ratings are intended to suggest feeding a particular product will result in a specific dietary response or health benefit for your pet.

For a better understanding of how we analyze each product, please read our article, "The Problem with Dog Food Reviews".

Remember, no dog food can possibly be appropriate for every life stage, lifestyle or health condition. So, choose wisely. And when in doubt, consult a qualified veterinary professional for help.

In closing, we do not accept money, gifts or samples from pet food companies in exchange for special consideration in the preparation of our reviews or ratings.

To learn how we support the cost of operating this website, please visit our public Disclosure and Disclaimer page.

Have an opinion about this dog food? Or maybe the review itself? Please know we welcome your comments.

Notes and Updates

07/09/2014 Last Update

  • Jeremy

    I believe you must be talking about the LID formulas they make. The Ultra did change formulas recently, but mostly it was removing lamb meal and shuffling some of the other ingredients around.

  • Candice Kamencik

    More protein is actually less waste produced, or as you so eloquently
    put it less “poo and farts.” The more fiber and vegetable matter a dog
    gets, the more frequent their stools will be. Protein is more easily
    digested and absorbed by the body, so there is less waste when fed a
    food with a high quality protein source.

  • Guest

    More protein is actually less waste produced, or as you so eloquently put it less “poo and farts.” The more fiber and vegetable matter a dog gets, the more frequent their stools will be. Protein is more easily digested and absorbed by the body, so there is less waste when fed a food with a high quality protein source.

  • Betsy Greer

    Unfortunately, the second ingredient is also about 80% water so there is no way there’s more meat protein than sweet potatoes.

  • LabsRawesome

    Seriously….You have no idea what you’re talking about.

  • yourmoms

    Seriously…unless you have a farm/hunting dog, over 24% protein is excessive. It won’t hurt the dog, but a lot of protein does not a good petfood make. Anywhere between about 18%-26% is great for house dogs and family pets. Any more and you are wasting money honestly. I guess if you like extra poo and farts, the more protein is better…

  • yourmoms

    I called the customer service line about this. They actually have changed the order of how they list ingredients. The ingredients are weighed and listed prior to dehydrating, so the sweet potato(with more water weighs more). After drying, the percentage of meat by weight is higher.

    I will say the new food rolls are aweful! I complained pretty hard on the phone

  • helen

    the ingredients have changed since being bought out, sweet potato is now the first ingredient, i was so disappointed i changed brands

  • swak

    hound dog
    richarddarlington.com

  • contrabantio

    To be honest, Natural Balance is the best food for my particular dog. I own an english bulldog and have given him everything from iams to royal canine bulldog specific. The NB with sweet potato limited ingredients is the best food yet. I use the rolls to grate over his food for a treat or add a spoonful of plain yogurt. The major difference is how much better his skin is. He has flea and seasonal skin allergies. When compared to other foods, this stuff seems to help alleviate some of the issues. Beyond that, I am blessed with a super healthy dog. I fed him NB as a puppy as well. The time he got sick was when I swapped immediately instead of going little by little.

  • Shawna

    Just to clarify Richele,

    Many of us think that Natural Balance are good foods in that they use MUCH better quality of ingredients (or at least did before they were bought–not sure now). But there are many foods on chewy and at many boutiques that have significantly higher protein. When comparing quality ingredient food to quality ingredient food, NB foods have below average protein amounts.

    And likewise, when comparing the 26% protein in NB Ultra to the 31% in Beneful, NB gets a higher rating, even though less protein, due to the quality of the protein used.

  • Hound Dog Mom

    Hi Richele –

    No dry Purina foods sold at grocery stores contain 10% protein.

    The protein levels in dry Beneful formulas range from 25% – 28%.

    The protein levels for Dog Chow’s formulas range from 21% – 27%.

    It’s possible you’re misreading the label.

  • Shawna

    Just wanted to make sure. It has been some time since I looked at grocery store foods so I looked up a few of them. Per the reviews here on DFA

    –Beneful has 31% protein and is rated 1 star
    –Dog Chow has 24% protein, 1 star
    –Kibbles N Bits 23% protein, 1 star
    –Pedigree 30% protein, 1 star

    The amount of protein in Natural Balance is in line with grocery store kibbles. BUT the quality of the protein is significantly better allowing it to have a much higher rating at 3.5 stars.

    Edit — to confirm as things change and Mike has to revisit reviews to catch up to those changes, I looked up the “as fed” info on the manufacturers website.

    Beneful “as fed” protein amount is 27% http://www.beneful.com/products/dry-dog-food/incredibites

    Natural Balance Ultra “as fed” protein amount is 23% http://www.naturalbalanceinc.com/product.aspx?ProductId=7

    Both are identical to what Mike reports as the “guarateed” amount (which is slightly different than the dry matter amount shown at the top of each review).

  • Richele Grenier

    I have to say I’m a little offended that you are all assuming I cannot tell the difference between wet and dry food. I assure you I have been looking at dry and am not attempting to compare wet and dry as equals.

    Purina (Beneful, Dog Chow), and thus any grocery store brand, which are relabeled Purina kibble, tends to hover around 10% as far as I’ve noticed. Yes, many brands will have a crude protein closer to 20% if you look at the grain-free option, but non grain-free has much lower protein content.

  • Shawna

    Hmmm? Interesting

    Can you give me an example of a grocery store kibble that has only 9 to 10% protein?

    As I mentioned before, if you are looking at canned foods you have to convert them to dry matter to compare them. Dr. Foster & Smith’s website has a good explanation of how to convert “as fed” to “dry matter” so you can compare their nutritional analysis to kibbled diets. http://www.peteducation.com/article.cfm?c=2+1659&aid=662

  • Richele Grenier

    Then perhaps the article should clarify “typical BALANCED dog foods,” which it does not. The average consumer would call a typical dog food one that is found in their local grocery store. And I have not limited myself to the big box pet stores, because I actually refuse to shop from them. I visit local, specialized stores and use sites such as chewy.com and petflow. Hardly limiting sources.

  • Dori

    Sorry Shawna, I answered to Richele before reading the last line of your post. If you or someone can explain to Richele the correct way to convert to dry matter I think that might help. I’m not sure if I explained it correctly or even if it’s actually correct. Thx

  • Dori

    I think what you are not taking into account that though they claim 9 – 10% protein, that figure then has to be converted to “dry matter” which is what Dr. Mike does on the individual reviews. That may be where you’re getting confused. You would have to look at the moisture content on the label and subtract the protein they claim from the moisture then what you’re left with is the dry matter protein %. (I believe that’s how it’s done if memory serves me correctly).

  • Shawna

    The minimum protein allowed for an adult dog in a “complete and balanced” kibbled diet is 18% and for puppies is 22%. Anything below that can not state they are complete and balanced. Canned foods state their amounts as an as fed versus dry matter basis. When converted to dry matter they will usually, if not always, have more protein than many kibbled diets.

    A few of the foods I feed with significantly more protein than 23% — Orijen reviewed here on DFA has 42% protein. Nature’s Logic has 38%, Nature’s Variety Instinct has 39%, Earthborn Primitive Natural 42%.

    If you limit your shopping to places like PetCo and PetSmart you are significantly limiting your options.

    If you are looking at canned foods, you need to convert the numbers to dry matter to be able to compare apples to apples.

  • Richele Grenier

    While I did find this article helpful, I must say I take issue with one line: “Below-average protein. Below-average fat. And above-average carbs when compared to a typical dry dog food.”

    What are you considering to be a “typical” dog food, then? I have been tirelessly researching dog food, going into pet stores to read product labels, reading reviews and veterinarian recommendations and guidelines, and 23% protein is, sadly, far above average! Most that I have seen can only claim 9-10%! So how can you call 23% “below-average”? I think you are living in a fantasy world where all dog foods contain 30%+ protein.

  • Yvette Frias

    my Siberian husky and black lab stopped liking it but the only good thing in was my husky got a shiny coat. Unfortunately They both started itching and black lab development and ear infection. So I got the totally awesome brand of food Whole Earth Farm the grain free chicken and turkey all breed all stages of life. They love it.

  • jess

    Should consider food rotation. I’m doing this for my 1 year old mini poodle. He is more than happy. I do mix with wet food too.

  • jess

    Agreed. To me no product in the market is perfect. Is all merely depends on your pet. Wellness is rated at 5-6 stars super premium food but just too bad that it does not work well for my poodle cos my girl couldn’t take any food which is high in protein. What is the actual cause of the nail to fall off? is easier for the vet to just said it was due to the food. If so, which ingredient of it that caused the problem. I just started my little girl with LID NB & I hope it works well on her. At least she eliminate less.

  • amy

    *too many potatoes/ sorry.

  • amy

    I had my 1 yr old chi/min pin on NB ultra and it was simply too high of carb at 53%. Developed smelly skin, yeast, ear inf and even a uti. This was all while on ultra and Natural balance LIDS. Too mutant potatoes and grains. Then switched to Whole Earth Foods and things improved. Now transitioning onto Nutrisca and even better results. Dog doesn’t smell and itching decreased dramatically. Just wanted to share. Nowmy goal is to have a 4-5 food rotation and I am entertaining the idea of Nutrisca, Amicus, wellness, Solid Gold and merrick. Even though the latter three have grains, they are below 43%. High carbs, I believe we’re the culprit. Natural balance LIDS were in the 60′s range.

  • Pattyvaughn

    Often pyoderma happens because of a food intolerance, so take the ingredient list of your current dog food with you to the store and try to find a food that is as different as possible. Make sure at the very least that the protein and carb sources are different.

  • Sherri Davenport

    My bassett hound has pyroderma (skin irritation) and I was wondering if anyone could suggest a food that would help.

  • CAR MAN 100

    my dog was raised on natural balance duck etc neaver had any truble i took her off it i dont no way i did shes 1 yr and 3 muths old now her stols wear hard and dry on the natural balance i think one day ill put her back on natural balance i dont no i reed what others say take it to heart

  • CAR MAN 100

    my dog likes natural choice lamb and rice she cleens the bowl all the time her stols our good she use to be pickey eather she use to scratch her self like crazey untel i gave her natural choice lamb and rice to each his owen i fund out if dog eates to fast to much doesnt chew food right they will trow up its nout the food

  • CAR MAN 100

    MY DOG USE TO SCRATCH HER SELF LIKE CRAZY I PUT HER ON NATURAL CHOICE LAMB SHE DIDNT SCRATCH SO MUCH GOOD FOR SKIN AND COAT SOME DOGS CANT EATE CHICKEN LAMB IS GOOD DOGS LIKE US THINGS THEY CANT EATE

  • InkedMarie

    The only ultra that starts with rice is the reduced calorie & the other one is the vegetarian.

  • Greyhoundzzz

    One of our local pet store owners had mentioned that the formula for Ultra had changed since they were acquired by Del Monte. I checked the label and confirmed that brown rice is now the leading ingredient. That’s not to say much since we really don’t know how close the percentages of each ingredient were…but I find it interesting that there have been numerous comments on different sites about their pets exhibiting changes to their eating habits (incl. mine). This is sort of a good read for future reference in either staying or switching from Natural Balance:

    http://www.littlebigcat.com/blog/natural-balance-pet-foods-sold-to-del-monte/

  • Candice Kamencik

    She might, but I’m not going to guess. Allergy, etc. isn’t a negative of the food though, it’s a medical condition of the dog, which is why I asked what exactly was wrong. If a person is lactose intolerant, that doesn’t mean milk is bad, same with dog food.

  • aimee

    She may be referring to Symmetric Lupoid Onchodystrophy

    A food allergy has been identified in a few cases of this disease, so it
    may be appropriate to go through a strict , 8-12 week hypoallergenic
    food trial.”

    http://www.dermatologyforanimals.com/faq-49/

  • Candice Kamencik

    What exactly would you like to be changed?

  • Candice Kamencik

    Can you share what exactly your vet said was wrong? Some kind of deficiency, etc. Cause that seems…really odd. You can feed your dog terrible food and it’s nails aren’t going to fall off.

  • JennyLee

    I have been feeding my small dog natural balance ultra for about three months. He’s 12 years old and has been very healthy most of his life. During the time that he’s been eating Natural Balance, all of his nails have fallen off. The vet has run numerous blood panels on him and has concluded that it is likely the food that is the problem. I plan on switching as soon as I can find something else. Just wanted to caution anyone else, if you’re dog is experiencing something similar it’s likely because of the food.

  • somebodysme

    That is a shame! Obviously something changed in the Ingredients. I’d write them and just ask if the ingredients have changed and see what’s different. I’m on the potato and rabbit and every time I open a new bag I cross my fingers because it’s really working great and I sure hope it doesn’t change!

  • William R James

    My lab-chow mix used to shed like crazy. I would brush everyday and sill. the inside of the house would be littered with lots of hair. A year or so ago I switch to N.B. Ultra dry and behold, the problem improve so much, that I no longer bother brushing because I don’t get any hair, and her coat has become very shiny and healthy. Clearly, to me diet has something to do with scheding . Lately, still using N.B Ultra dry, her coat does not seem as healthy, and she bites at her coat and has developed some hot spot. I don’t know, but I’m switching dog foods.

  • CR

    I put my dog on NB just over a year ago. I didnt know much about dog nutrition for sadly most of my dog’s life. Hes now 9. Im scared to even imagine what those other horrible foods may have done.

    Hes had chronic ear infections in his younger years (lab mix) and a VERY sensitive stomach.

    Ive noticed with NB ive had the least amount of stomach upsets and bouts of diarrhea. They still happen from time to but the amount has been drastically reduced.

    Havent had ear infections come back in a very long time (not contributing that to the food, they seemed to stop coming back some time before I started him on NB.

    Havent really noticed difference in energy levels or coat though. He is getting older:(

    Has anyone used or heard of NuVet? The claims on the site are a little ridiculous. Im considering but dont know if its complete bs or not.

  • DJ Catlin

    I have been recently experiencing the same problems with Natural Balance Ultra. My dog has been eating it since he was weaned but recently it has been really irritating his digestive system.

  • Pattyvaughn

    It isn’t good for your dogs digestive system to eat the same food long term. There is no such thing as a perfect food so feeding a variety of foods is much healthier. rotational feeding supports a wider variety of probiotics in the gut, which in turn proides a huge boost to your dogs immune system. You should pick a few different foods and rotate between them.

  • Katie

    My dog has been eating the Natural Balance Ultra Original for almost her entire 5 years – it seems the recipe has changed as it in not agreeing with her anymore and it even looks different. It is a lighter color and has affected my dogs digestive system. Frustrated…

  • Hound Dog Mom

    Unless Del Monte alters the formulas the review isn’t going to change. Dr. Mike’s reviews are based on the ingredients and the nutrient analysis – not who owns the company.

  • AnonymousViewer

    In light of the news below, could you revisit this review by 2014?

    http://www.bizjournals.com/sanfrancisco/blog/2013/05/del-monte-foods-natural-balance-pet-food.html

  • Troika

    I feed 14 Dalmatians Natural Balance Ultra Original. I love this food. I understand there were recalls on some varieties because of the Diamond plant problems. Those did not affect the plants where the dog food I order is created. The 23-24% protein is a perfect level for a breed that forms uric acide stones from high protein content. I fed another famous brand for 16 years and started having severe gastrointestinal problems with my seniors. While I changed varieties within the brand (ranked low on this site), the problems persisted. Once I changed to NB, I had dogs I had to force-feed eat eagerly. Stools and coats are lovely.

  • my car man

    i can remmber in the old days dogs eate left overs from the table u didnt have all kinds of dog food in the store they wear healthy lived long life no one wants dog to fat dont over feed yur dog hamburger and rice cooked is good for dogs some dogs whunt eate there dog food after that some dog foods come from kill houses wear kill horses and ect all dogs our nout the same like ppl we can eate only certin things i was feeding my dog natural balance after reeding bad things on it now i dont no what to feed her her stoll is good on it nout messey just right am confused

  • Pattyvaughn

    Maybe you should look up megacolon instead.

  • Cynthia Pharm.D.

    Sorry but I dont believe you. Think ur a scam for the company…….

  • cynthia Pharm.D.

    Natural flavor usually refers to a form of MSG. I won’t eat it & certainly won’t give it to my dog.

  • Hound Dog Mom

    Yes, there can still be MSG because natural flavor can potentially contain MSG. They can also tell you that the food is MSG free if they don’t directly add the MSG and it’s just in the natural flavoring.

  • Tenar41146

    Thanks for your reply!

    NB claim on their website that they do not use artificial flavors in their foods. Can they legally still add glutamic acid/MSG to this food? 

  • http://www.dfwpugs.com/ sandy

    Yes this food was recently updated, but the previous review date was 5/2011.  Some of the old reviews would exclude the lower rated formula of a group in the average.  But these updated reviews takes all the formulas into account.  It’s kind of like why throw out/disregard the food with the lowest grade?  The food should be graded for all their formulas.  If you’re not feeding the reduced calorie formula, the other 2 are probably very close to 4 stars.

  • Tenar41146

    But it was rated 4 star on this site until very recently.
    So what changed? does this kibble now has a new formula with less meat? or does this site has a new more severe rating system?
    I started feeding this kibble to my dog about 3 weeks ago, so I would like to know.

  • http://www.dfwpugs.com/ sandy

    The group average of just 24% protein along with 56% carbs does not qualify it to be a 4 star.

  • tenar41146

    Why has this formula been downgraded from 4 stars to 3.5 stars?

  • Hound Dog Mom

    Hi tenar41146 –

    The AAFCO defines “natural flavor” as:

    “The term natural flavor or natural flavoring means the essential oil, essence or protein hydrolysis, distillate, or any product of roasting, heating or enzymolysis, which contains the flavoring constituents derived from a spice, fruit or fruit juice, vegetable or vegetable juice, edible yeast, herb, bark, bud, root, leaf or similar plant material, meat, seafood, poultry, eggs, dairy products, or fermentation products thereof, whose significant function in food is flavoring rather than nutritional.”

    Unfortunately “natural flavor” can often contain free glutamic acid (MSG).

    http://www.truthinlabeling.org/nomsg.html