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Iams vs Purina ONE: Which Dog Food is Better?


Last Updated: May 9, 2024 | 10 min read | 3 Comments

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With so many brands on offer claiming to be the best, it’s no wonder the vast majority of dog owners find it hard to choose between brands. Today, we are looking at Iams vs Purina ONE. This is a complex debate because both have a rich heritage and create good value and quality foods.

Iams and Purina ONE are not all that different, which is why so many people have a hard time choosing between these popular product lines. But there are a few key differences that you need to know to make the best choice for your pup.

We will take you through their brand history, recall history, ingredients they use, and the range of formulas they have. So, let’s pit these companies against each other to find out what they are all about.

Purina ONE SmartBlend Chicken & Rice Adult Formula Dry Dog Food
Our Rating

Top Pick For Puppies

Iams Puppy

Iams ProActive Health Mature Adult Dry Dog Food
Our Rating

Top Pick For Adults

Purina ONE

Iams ProActive Health Smart Puppy Original Dry Dog Food
Our Rating

Top Pick For Seniors

Iams Mature Adult

Brand History

Dog eating out of bowl
Brand history is very important, especially when it comes to dog food for your beloved pup.

Whether they’ve been around for decades or just a few years, their ethos, values, and track record will speak volumes about the quality of their food. If they have a large fan base and appear popular, it’s because they are doing things right. So, let’s take a good look at their origins.


Iams have a rich history going back 75 years. Founded in 1946 by Paul Iams, they have long been a groundbreaking company that backs their food development with science and research. Paul Iams graduated from Ohio State University as a formally trained and educated animal nutritionist. He created well-researched, balanced, and nutritious food recipes to ensure dogs receive what they need to live a long and healthy life.

Paul Iams was so successful in his venture that he went on to create the Eukanuba brand too. Iams has changed hands many times during its lifetime but is currently owned by Mars, Inc. Despite the change of owner, the brand ethos has remained, and they continue to create great value for well-balanced food available the world over.

Purina ONE

Purina is a global brand with its headquarters in St. Louis, Missouri, USA. They are currently owned by another food giant, Nestle. But initially it was the brainchild of William H. Danforth in 1894. He began in the animal feed business with multiple other partners — known as the Robinson-Danforth Commission. It later became Ralston Purina when the company ventured into pet food, focused on researching and developing nutritious, wholesome food.

Purina is the company hailed as the creators of what we now call ‘kibble.’ It is based on a technological process they developed and named extrusion. Since then, the company has grown in popularity and experience. Purina ONE is one of many product lines in the Purina brand, and they were the first all-natural dog food. It’s one of Purina’s budget-friendly lines.


Recall under magnifying glass on top of Broccoli head
A food recall occurs when a company identifies a safety issue with one of its products and takes steps to remove it from the market.

A pet food company’s history of recalls is affiliated with its food safety record. It paints a picture of how seriously they take their responsibility as a food producer and how safe it is for our beloved fur babies. Some companies will act swiftly and be open and honest about their mistakes and shortfalls. Others will go out of their way to hide shortcomings and deflect blame.

The U.S. Food & Drug Administration (FDA). The Food and Drug Administration (FDA) regulates food recalls keeping a record of when it happens and investigating if animals were harmed. We can detail the brand’s history of recalls by collating the info available on the FDA and American Veterinary Medical Association (AVMA) websites.


Iams is a massive global company that has very little in the way of full-scale recalls. There are only three recalls in the past ten years, according to our sources. In December 2011, Iams voluntarily recalled a puppy food batch. This was after their routine checks detected higher than acceptable levels of aflatoxin.

In March 2013, Iams voluntarily withdrew their Shakeables turkey and lamb dog treats due to the potential for mold growth within the packets. And finally, in August 2013, Iams announced a voluntary recall of specific lots of its dry pet foods because of potential salmonella contamination. Considering how long they have been around, this is an impressive feat for sure.

Purina ONE

Purina is another household name with many products and facilities to their name. Despite this, only six recalls were recorded by the company in the past ten years, with two accounting for dog food and only one of those attributed to the ONE dog food line. This is a great testament to their dedication to producing quality food with our pup’s best interests at heart, especially under the ONE brand name.

In August 2013, Purina issued a voluntary recall of a limited number of 3.5-pound bags of Purina ONE Beyond due to possible contamination with salmonella bacteria. In March 2016, Purina announced a voluntary recall of select lots of its Beneful and Purina Pro Plan wet dog foods. Their own quality assurance checks found that they did not contain the recommended level of vitamins and minerals. But this did not affect this brand.

Food Ingredients

Dog paws with bowl full of ingredients
Both brands claim to use high-quality ingredients while offering great value for money.

Let’s investigate the validity of these claims and delve deeper into the ingredient lists.


​Iams is popular, not only because they offer quality food, but because they do so at a reasonable price. But how does this reflect in their ingredients lists? In most recipes, real meat is the first ingredient, which is a great sign of quality. But this is not always the case. Chicken is the most common protein source, with two lamb-based options available in the adult life stage.

Iams also use meat by-products, which is a controversial ingredient. Many say it is a lower-quality meat ingredient because it is the rest of the non-meat animal carcass. But the quality all depends on what goes into this ingredient. Feet, feathers, and beaks are not of great quality, whereas organs and blood are nutritional. Sadly, Iams does not appear to specify what makes up this controversial “ingredient”, so it’s difficult to comment on the quality of their meat by-products.

Iams lists a mixture of healthy omega-six fatty acids. These are great for doggo’s skin, coat, brain and eye function, cardiac support, nutrient absorption, and much more. Ingredients include chicken fat and flaxseed. However, there seem to be few ingredients that offer healthy omega-three fatty acids, which is seen in most high-quality kibbles.

Iams is a grain-inclusive brand only. The discussion on whether you should feed your pup a grain-inclusive vs grain-free diet is controversial, and there is no clear winner unless your dog has dietary requirements for either variety. However, by offering only grain-inclusive options, Iams is limiting their doggy audience. If you require a grain-free diet, Purina ONE is the only contestant in this debate.

Iams do not use artificial preservatives or flavors, which is great. These have no place in a doggy diet as they irritate doggy digestive systems. But, they do use unnecessary additional ingredients such as caramel color. This is usually derived from natural sources, but not always. This is a poor practice not used by higher quality brands. Not only can it irritate a dog’s system, but it is only there to please your eye – Fido really couldn’t care less what color his grub is.

All of their recipes list added vitamin and mineral supplements that help support your pup’s immunity, which means the power to fight illness and disease. This is a sign of a quality product because many cheaper alternatives do not include these micro-ingredients. Overall, Iams is a budget brand, and they use a blend of quality and potentially controversial ingredients.

Purina ONE

This is mainly a grain-inclusive brand, however, they also offer a handful of grain-free options. This is a bonus compared to Iams because it caters to a wider set of canine needs.

Additionally, they use real meat as the first ingredient in all of their recipes, which is an improvement on Iams’s efforts. ONE incorporates a wider variety of meats, including chicken, turkey, beef, lamb, salmon, and duck. Meat by-products are also listed among ingredients in their recipes.

Purina ONE uses unnecessary ingredients such as caramel color, similar to Iams. They also use unnecessary flavor ingredients, such as liver flavor, seen in many of their recipes. The meat, grains and produce ingredients alone should be enough for our pups, and most higher quality brands do not use these fillers.

Although they have more options than Iams with their grain-free recipes, they also use more controversial ingredients. However, considering the lower price point compared to other brands, this is unsurprising. Still, both are highly rated brands. And many dogs do well on these recipes, so the lower quality ingredients aren’t an issue for many canines.

Range of Formulas

Dog food ingredients
Like humans, all dogs are different and have different taste buds and dietary needs.

A dog’s three different life stages have varying nutritional requirements. So, if brands want to reach the entire doggy community, they should to cater to them all with a wide range of formulas. Let’s see how they compare.

Puppy Formulas

The most important life stage in any dog’s life is the initial life stage known as puppyhood. This usually lasts up until 12 and 18 months of age, depending on the breed. Many argue that this is the most important life stage because it sets the foundations for a healthy body and life. Puppies need extra protein as this provides growing power and additional omega fatty acids assist with brain and eye development.

Iams Puppy

Purina ONE SmartBlend Chicken & Rice Adult Formula Dry Dog Food
  • 3 kibble flavors and a canned pate.
  • Formulated to support the nutritional needs of growing puppies.
  • Made with real meat as the first ingredient.
  • Premium-sourced proteins.
  • Key nutrients similar to those a puppy would find in her mother’s milk.
  • Includes omega 3 and grains.


Iams offers a total of three puppy recipes, each designed for a different-sized canine. One option is for small and toy pups, and another is for large and giant breeds. The final option is the original puppy recipe that caters to a general population of dogs, regardless of size.

However, this is where the puppy variety stops. All three options are chicken-based recipes, meaning if your pup doesn’t like or is intolerant of this commonly used meat, Iams is not an option. There are no grain-free options either.

Purina ONE

There are two puppy options. The first is for large puppies, and the other is for all other sizes. This means that small puppies are limited to normal-sized kibble, which is especially problematic for toy pups. Like Iams, both of these recipes are chicken-based and grain-inclusive.


The winner of the puppy variety round is Iams. They have one more option in their puppy food lineup. Small and toy-sized puppies are catered for with their additional smaller-sized kibble option, where Purina ONE fails to deliver on this front.

Adult Formulas

Adulthood is the next life stage that typically lasts between one and seven years of age. By one year old, dogs have completed most of their growth. Meaning they need less protein and fats and more of a well-balanced diet. How do they compare?

Purina ONE Adult Formula

  • Wide variety of flavors and types.
  • Available as kibble or wet food.
  • Comes in 7 types of proteins.
  • Real meat is the first ingredient.
  • Smart blended with other high-quality ingredients.
  • Has Omega-6 and other nutrients for adult dogs.


Iams offers seven adult options for adults across their entire range. There are three standard kibble recipes, catering to large breeds, small breeds, and all-sized pups who prefer smaller kibble bites. There are two healthy weight options, one for large breeds and the other for all other sizes.

There are two lamb options, one for large breeds and the other for everyone else, which is improves on the puppy stage where all the options are chicken-based formulas. However, these lamb recipes still contain chicken protein. Meaning it is not suitable for those intolerant of chicken meat, just those who prefer more lamb over chicken. Like before, there are no grain-free options.

Purina ONE

There are 14 dry kibble options, a massive upturn on their puppy life stage offerings. There is an option for large breeds, small breeds, and smaller bites for those who prefer smaller chunks to chew. There is a chicken-based formula and lamb-based formula for all breeds. And one healthy weight option too.

Five of the adult options are from their True Instinct line. This means that those looking for a slightly higher quality kibble that is nutritionally dense with a higher protein content have choices here. Each option uses different meats, and there is one grain-free option available too. There are also three dietary-specific options, including digestive health, joint health, and sensitive systems.


The easy winner here is Purina ONE. They have double the formulas, but they also have specific health options and a grain-free recipe.

Senior Formulas

Finally, the last stage of a dog’s life is the senior stage. Like us humans, seniors become less active, and their digestive system slows, so they need much less fuel, easier-to-digest formulas, and more glucosamine for their joints. For all these reasons and more, it’s crucial to switch your pup’s diet to a senior kibble when the time is right. So, let’s see how these brands compare in the final life stage.

Iams Mature Adult

Purina ONE SmartBlend Classic Ground Chicken & Brown Rice Entree Adult Canned Dog Food
  • Comes in 2 kibble flavors and a canned pate.
  • Formulated to support the nutritional and wellness needs for senior dogs.
  • Ral farm-raised meat as the first ingredient.
  • Key nutrients to support bone and joint health.
  • Antioxidants for immune system support.
  • Wholesome blend of prebiotics and fibers.


Iams offers two senior kibbles – one for large breeds and the other for all other sized doggos. Both recipes are chicken-based, and they are grain-inclusive. The large breed option has an average glucosamine content compared to other brands. Sadly, there is no glucosamine content information available for the other recipe, so we cannot comment on this all-important joint support ingredient.

Purina ONE

This brand offers one senior-specific recipe. This is disappointing as small and large breeds miss out on senior-specific kibbles and are restricted to the one generic senior kibble option. However, this option has a slightly higher glucosamine content compared to Iams.


The senior trophy goes to Iams. They have two options compared to one, meaning they cater to seniors in their final life stage.  

Canned Foods

It’s also important for brands to offer wet food options. Although dried kibble should be the first preference, some dogs need a splash of wet food in addition to their kibble pieces. This could be because they are fussy pups and prefer juicer meat, or they might have trouble chewing hard kibble on its own. Whatever your dog’s reason, let’s take a look at what Iams and Purina ONE offer in terms of canned food.

Purina One Wet Food

  • Comes in a variety of flavors and blends.
  • Available for dogs in all stages of life.
  • SmartBlend comes in True Instinct and regular.
  • Made with real meat and natural ingredients.
  • Contains antioxidants and vitamins.


Iams offers six wet food options. There are four different adult flavors, one puppy option, and a final senior pick. Each recipe is a pate formula, and chicken is the preferred meat here. All of the options are grain-inclusive.

Purina ONE

Offering a total of 16 canned options, but there is one puppy option; the rest are for adult dogs. They also sell products in their higher quality True Instinct line and several grain-free options. 


In this final round, Purina One wins the award for wet food offerings. They offer more than double the number of canned options compared to Iams. Plus, they have higher quality choices for those pups needing grain-free alternatives. The only thing they do not offer in comparison to Iams is that there is no senior option.

Final Thoughts

Overall, you can see that Iams and Purina ONE are very similar, which is why so many owners have trouble choosing between the two brands. They both have an impressive safety record, and they also use a mixture of quality and controversial ingredients. Ultimately, they are both highly rated brands that strive to create top nutrition for our pups at a budget-friendly price. We recommend these brands to anyone looking for the best of both worlds.

Purina Pro dog food in bowl

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