As a result, you might be tempted to assume that they’re basically the same, but that’s not the case. We looked at both brands, taking a deep dive into their histories and manufacturing practices, and the more we dug, the more a winner began to emerge.
So which food ended up on top? You’ll have to keep reading to find out.
A Sneak Peek at the Winner: Purina
These two foods are fairly similar from a bird’s-eye view, and you’d have to really dig into their ingredients to spot any differences. We feel that Purina uses fewer questionable ingredients to make their food, which is why they won this matchup.
The winner of our comparison:
In our opinion, the best foods that Purina makes are:
- Purina ONE SmartBlend True Instinct Natural Grain-Free Formula Adult
- Purina Beyond Grain Free Natural Adult
- Purina Pro Plan SPORT Formula Adult
Below, we’ll go more in-depth on the factors that went into making this decision, as well as specific instances in which we compared the two brands.
IAMS is a subsidiary of Pedigree PetCare, the largest petcare company in the world. However, it has a long and distinguished history in its own right as well.
IAMS is One of the Oldest Pet Food Companies
Until the mid-20th century, most dogs were only fed table scraps or allowed to eat whatever they could catch. Before that, a few commercially-produced foods were made, but these didn’t catch on to any great extent.
Mass-produced kibble started hitting shelves in the 1920s, and in the 1940s an animal nutritionist named Paul Iams began to suspect that dogs would fare better if fed a specialized diet.
He founded his own dog food business, The Iams Company, in 1946, and a few years later he developed the first kibble to use animal-based protein, thereby revolutionizing the entire industry.
The company almost went bankrupt in the 1970s due to a refusal to lower their manufacturing standards in the face of rising meat prices, but a man named Clay Mathile acquired the company and turned into a dog food behemoth. He later sold the business to Procter & Gamble, who then sold it to Mars, Inc., the owners of Pedigree PetCare.
IAMS Was the First Company to Make Foods for Specific Life Stages
It’s easy to forget that specialized dog foods are a relatively recent innovation. For most of the previous century, the prevailing attitude was “kibble is kibble.”
IAMS began to change that in the 1980s when they created a formula especially for puppies. This was the first acknowledgement that dogs have different nutritional needs at different times of their lives; from there, it was natural to transition to senior and adult lines as well.
While IAMS can’t take all the credit for the recent trend of making highly specific, highly-nutritious dog foods, it’s clear they helped to get the ball rolling.
IAMS Has Fallen Behind the Times a Bit
Unfortunately, it appears that IAMS’ penchant for innovation has stalled in recent years. This may be a result of being bought by Pedigree, which values budget-friendliness over nutritional value.
The recent trend in dog food is to create kibble that uses little or no cheap grains or animal by-products. While not as bad as many other foods in the Pedigree line, IAMS is nevertheless lagging behind some of its competition in this regard.
This is a Decent Food at a Low Price
IAMS can’t compete with many of the newer, high-end brands in terms of nutritional value, but it’s still a decent food at a low price. Given that you can buy it nearly anywhere, it’s a respectable choice for dog owners who don’t have unlimited budgets or the time to spend scouring shelves at boutique dog stores.
Purina is the second-biggest pet care company in the world, trailing only Pedigree (which owns IAMS). They have three primary lines: Purina Dog Chow, Purina ONE, and Purina Pro Plan. However, they own several smaller dog food companies as well.
Purina is Based in the USA
The brand was started in the United States, and most of its production is still centered there. It has multiple processing plants in the Midwest and Northeast, so virtually all its food is manufactured stateside.
The Brand Believes in Specialization
There’s a Purina-brand food for anything that ails your dog. They have a dazzling array of recipes and formulas, each targeting a different health issue or life stage.
While IAMS may have started the specialization craze, Purina has taken it and run with it.
The Food Varies Wildly in Quality
Their basic food — Purina Dog Chow — is cheap and filled with as many questionable ingredients as anything IAMS makes.
However, their two other lines, ONE and Pro Plan, have formulas that range from middle-of-the-road to high-end. As a result, you’ll see quite the disparity in terms of ingredient quality from one bag to the next.
The Prices Vary Wildly, Too
You can get some Purina formulas for very cheap — but these will largely have dodgy ingredients.
Conversely, they also offer grain-free and limited-ingredient formulas that check just about every box, nutritionally speaking. Of course, these will cost you quite a bit more.
3 Most Popular IAMS Dog Food Recipes
1. IAMS Proactive Health Minichunks & Adult Dry Dog Food
- Contains one (1) 40 pound bag of IAMS Proactive health adult minichunks dry dog food chicken
- Veterinarians recommend IAMS; we’ve got your dog’s diet down to a science
We like that the first ingredient is real chicken, but the ingredients list starts to get rocky after that.
There’s quite a bit of cheap grain (mostly corn) in here, as well as animal by-products and artificial colors. We’d prefer if all these ingredients had been left out.
However, there’s some good stuff to be found, too. Flaxseed and chicken fat are full of omega fatty acids, dried beet pulp is good for keeping dogs regular, and carrots are just plain good.
Overall, this food is middle-of-the-road in terms of both protein, fat, and fiber (25%/14%/4%, respectively). However, all those numbers are pretty good for a food this inexpensive.
2. IAMS Proactive Health Large Breed Adult Dry Dog Food
- Contains one (1) 30 pound Bag of IAMS Proactive Health Adult Large Breed Dry Dog Food Chicken
- Veterinarians recommend IAMS; we’ve got your dog’s diet down to a science
Designed for bigger mutts, this food also has chicken as the first ingredient, and even pushes the corn down a spot on the list. However, it’s still there, and it’s accompanied by a whole lot of other grains.
That’s odd, because grains are the source of a lot of empty calories, and large dogs don’t need to carry around any extra weight. It puts quite a bit of strain on their joints, but that’s ameliorated somewhat by the fact that this formula has a decent amount of glucosamine in it.
It’s very similar to the formula above, in fact, except it’s lower in both protein and fat (and slightly higher in fiber). Most of the glucosamine we just mentioned comes from animal by-products, too.
Big dogs should love the large kibble, though, and it’s crunchy enough to help clean their teeth. We just wish more attention had been paid to their waistlines.
3. IAMS Proactive Health Adult Dry Dog Food for Healthy Weight
- Contains one (1) 29.1 pounds bag of iams proactive health large breed adult healthy weight dry dog...
- Veterinarians recommend Iams; We’ve got your dog’s diet down to a science
While the bag says that this formula is designed for large breed dogs, there’s no reason why pooches of any size can’t eat it.
The only issue is you might not want to feed it to them, especially if they’ve been packing on the pounds lately. We generally believe that, to control weight, you need to boost protein and fat, but this recipe takes the opposite approach and loads up on cheap carbs.
Whole grain corn is the first ingredient, and most of the protein comes from chicken by-product meal. As a result, there’s not much overall protein inside (22%), and since actual chicken is well down the list, you can guess what the quality of the meat is like.
It compensates by being low-calorie, but unfortunately, it’s low in nutrients, too. We like that they included flaxseed and carrots but sandwiched between those two ingredients you’ll find salt and artificial coloring.
Overall, this food has a negative ingredient for each positive one, and it makes us question the company’s overall approach to weight loss.
3 Most Popular Purina Dog Food Recipes
1. Purina ONE SmartBlend True Instinct Natural Grain-Free Formula Adult
- 12.5 lb. Bag - Purina ONE SmartBlend True Instinct Natural Grain-Free Formula with Real Chicken &...
- 30% protein, including real chicken as #1 ingredient, helps support strong muscles
This is maybe the best recipe in the entire ONE family of foods, as it’s one of the few that doesn’t have cheap fillers and animal by-products.
Instead, it uses real chicken as its base, then adds chicken meal and beef fat on top of that. There’s canola meal and cassava root flour in place of corn or wheat, and the overall protein level is high (30%).
It cheats a bit to reach that level, though, as some of that comes from plant-based sources that your dog might not process as well. There’s egg in here, too, and that may cause some digestive issues for your pooch.
Overall, this is a fantastic food — and it’s priced as such. Your dog (and his vet) will thank you, though.
2. Purina Pro Plan SPORT Formula Adult
- One (1) 24 lb. Bag - Purina Pro Plan Grain Free, High Protein Dry Dog Food; SPORT Performance 30/20...
- High-quality protein, including real chicken as the first ingredient
This is one of the best recipes in Purina’s Pro Plan line, and it’s aimed at extremely active dogs. If your dog is an athlete, this has all the clean calories he needs to perform at his best.
Of course, if your pup is more of a couch surfer than a windsurfer, this will be too calorie-dense for him. There’s a lot of fuel in here, and dogs that don’t burn it off will get fat quickly.
There’s little to quibble with in the ingredients list, though. Real chicken, beef fat, fish oil — it has it all. We might remove the dried egg product and cut down on the plant protein, but other than that there’s not much to argue with here.
The protein and fat levels are high: 30% and 20%, respectively. There’s also a good amount of fiber (5%) in here, largely from the pea fiber and dried beet pulp.
This food isn’t for every dog and buying it for a sedentary pup would be like you downing a protein shake and then settling in for a Netflix marathon. However, for active dogs, you’ll be hard-pressed to find a better food.
3. Purina Dog Chow Complete Adult
We included this food to show that Purina doesn’t always use the finest ingredients.
This is their most basic kibble, and it’s also generally their most inexpensive. They manage that by cutting costs, and you can see the results of that from the very first ingredient: whole grain corn.
It doesn’t get much better after that, either, as the first protein is meat and bone meal. That’s not as bad as it sounds (in fact, there are a lot of important nutrients in there), but we’d prefer to see lean meat before it. You won’t find real chicken until seven ingredients down.
There are quite a few other disreputable foods in here, too, including whole grain wheat, egg and chicken flavor, and animal digest (don’t ask).
There’s beef fat, too, which adds omega fatty acids and glucosamine, but it’s not quite enough to counterbalance everything else they scraped into this kibble.
Recall History of IAMS and Purina
There have been two IAMS recalls in the past decade. The first was in 2011, when they issued a voluntary recall over concerns that their dry food had aflatoxin levels over the acceptable limit. In plain English, they were worried about mold.
The next recall happened in 2013, when the FDA issued a recall of several of their recipes over concerns of a possible Salmonella contamination. To the best of our knowledge, no animals were harmed as a result of eating the foods involved in either recall.
As for Purina, they have two recalls of their own in the past decade. They also had a Salmonella-based recall in 2013, although the contaminated food was limited to a single bag.
Then, in 2016, they recalled some wet food over concerns that the food didn’t have as many vitamins and minerals as the label indicated. The food wasn’t believed to be dangerous, however.
IAMS vs. Purina Comparison
(Now comes the big comparison. What metrics are relevant to compare these on? Ingredients? Price? Selection? Nutritional value? Customer support? Etc.) – As always, remember to break up into subheadings)
We’ve given you a broad overview of both companies, as well as compared some of their most popular foods. Now it’s time to pit them head-to-head in a few pertinent categories:
For the most part, both foods use comparable ingredients, especially at the lower end of their price range.
Purina’s higher-end foods will be heavier on real meat, so most dogs will prefer those to the basic IAMS recipes. However, IAMS uses more artificial flavors, and your dog might be as tempted by that as you are by the sight of the Golden Arches.
We’ll give the slightest edge to Purina here, but with the acknowledgment that this will vary from food to food.
Their basic kibbles are almost identical in terms of nutritional value, and that’s not a good thing in either case.
However, Purina’s ceiling is much higher, as their premium foods are packed with quality ingredients. IAMS has some good foods in its lineup too, but they can’t compare with the best of Purina’s best.
Generally speaking, IAMS will be cheaper than Purina.
Purina’s most basic kibble (Purina Dog Chow) costs roughly as much as IAMS’s basic kibble, but past that, almost all of Purina’s options are pricier.
This one definitely goes to Purina. They have a staggering array of formulas, and you can almost certainly find one that seems like it was tailor-made for your pet.
Their staggering array can certainly stagger you. You could lose an entire day browsing their catalogue and trying to decide which kibble is best for your dog.
As noted above, these foods are almost equal at the bottom end of the spectrum. However, Purina outperforms IAMS enough at the higher end to earn the nod here.
IAMS and Purina are two of the most common pet foods you’ll find, and they’re both good options to feed your dog. However, if we had to choose one, it would be Purina, as it’s easier to find high quality ingredients in their product lines.
If you’re on a limited budget, though, IAMS may be a better place for you to start looking. You can find good-enough formulas from them, and almost every single one is within the average pet owner’s reach.
Those who are more concerned about the quality of their dog’s food should opt for one of Purina’s premium products, though. They’re some of our favorites, and they can provide your best friend with everything he needs to stay happy and healthy.
Emily started this blog out of pure passion. She LOVES her 3 dogs; Chew Barka, Cooper & Nelson, and spends countless hours every day playing with them.
When she’s not nerding out on dogs, you’ll find her on a snowboard or in the kitchen baking chocolate brownies.
She’s been featured in PetAware, Dogtime, and ModernDog.
- A Sneak Peek at the Winner: Purina
- About IAMS
- IAMS is One of the Oldest Pet Food Companies
- IAMS Was the First Company to Make Foods for Specific Life Stages
- IAMS Has Fallen Behind the Times a Bit
- This is a Decent Food at a Low Price
- About Purina
- Purina is Based in the USA
- The Brand Believes in Specialization
- The Food Varies Wildly in Quality
- The Prices Vary Wildly, Too
- 3 Most Popular IAMS Dog Food Recipes
- 1. IAMS Proactive Health Minichunks & Adult Dry Dog Food
- 2. IAMS Proactive Health Large Breed Adult Dry Dog Food
- 3. IAMS Proactive Health Adult Dry Dog Food for Healthy Weight
- 3 Most Popular Purina Dog Food Recipes
- 1. Purina ONE SmartBlend True Instinct Natural Grain-Free Formula Adult
- 2. Purina Pro Plan SPORT Formula Adult
- 3. Purina Dog Chow Complete Adult
- Recall History of IAMS and Purina
- IAMS vs. Purina Comparison
- Nutritional Value