Purina Pro Plan vs Hills Science Diet Dog Food Showdown

Zack Keithy, our author, is a certified veterinarian technician (UC Blue Ash) for over 6 years (contact him here). The articles written here are based on his expertise and experience, combined with a review by our expert vet reviewers including Dr M. Tarantino. Learn more about us here.

I know how hard it can be to choose between two great options—especially when they’re both so good at what they do.

Purina Pro Plan and Hills Science Diet are both well-known brands, with a long history in the pet food industry.

Both these companies have a reputation for making quality products, and their mission statements are full of all the right words that make you feel like you’re doing the best thing for your pet.

But which one is actually better?

In this Purina Pro Plan vs Hills Science Diet dog food comparison post, I will share my findings of these two brands, basing them on 6 important factors you should use when choosing food for your dog.

Overview: Purina Pro Plan vs Hills Science Diet Dog Food

Purina Pro Plan and Hills Science Diet are premium dog food formulas made by large companies that produce many different kinds of pet food for dogs and cats.

Both brands use high-quality ingredients like meat, grains, and veggies in their products that have been selected through a rigorous screening process.

Given that there are so many similarities, how do you go about choosing either one?

We look at these 2 brands in more detail below.

The sections will focus on the following factors:

• Brand Reputation
• Ingredients
• Key Nutrients
• Range of formulas
• Product Safety and Recall
• Price

1. Brand Reputation

Purina Pro Plan

Purina offers a number of product lines, with Purina Pro Plan being one of their best-known and premium selections.

William H. Danforth established Purina, previously known as Purina Mills, in 1894.

The company started out making animal feed but eventually shifted its focus to domestic pet food and now is one of the oldest dog food companies in the world.

The brand is today one of the most well-known globally and is widely available in most countries.

They own a wide range of manufacturing and research facilities, including one specifically for the study of animal health.

For many years, they have been setting the standard in the sector and are widely regarded as one of the top brands, with a team of hundreds of scientists and veterinary nutrition specialists.

Hill’s Science

Most likely, this business doesn’t require much introduction too.

Globally, the brand Hill’s is linked with dog food, and veterinarians frequently cite it as one of the best options.

They sell a variety of dog food items, including the popular line of prescription food brands like i/d and z/d.

Hill’s is regarded as a pioneer in food science and research, earning it a devoted following of dog lovers like ourselves.

Through Hill’s Food, Shelter & Appreciate program, which has aided over 11 million pets since its inception, they have placed a major emphasis on assisting shelter dogs, and I love that!

2. Ingredients

In this comparison of Purina Pro Plan and Hill’s Science dog food, we will focus on the following dry food product from each company:

• Purina Pro Plan with Probiotics (suitable for all life stages)
• Hill’s Science Diet Dry Dog Food, Adult 1-5, Large Breed

Purina Pro Plan

The science-driven Purina employs more than 500 scientists and nutritionists for dogs and invests millions of dollars across various research sites in order to develop the best dog food recipes.

With Purina Pro Plan, which comes in grain-inclusive and grain-free varieties, the first ingredient is always real meat.

You will also come across the use of meat by-products, in this case from chicken, which some people may find offensive but which, in our opinion, is completely permissible.

Dog food production is subject to tight regulations, and it may only be used after passing a test.

Since meat by-products like liver are higher in protein than ordinary muscle meat, they are undoubtedly good for your dog.

The Probiotics Shredded Blend High Protein Adult Dry Dog Food, one of its best-selling items, has additional digestive aids too.

Here are the top 5 ingredients used in this particular kibble:

• Chicken
• Rice
• Whole wheat grain
• Poultry by-product
• Soybean meal

Potential harmful ingredients: None.

Hill’s Science

One of the four brands of dog food under Hill’s umbrella is Science Diet.

This specific recipe was created to meet the needs of dogs at various phases of development.

Science Diet dog food offers a wide range of precisely balanced products with advantages that have been clinically shown to boost vitality and well-being at any age or lifestyle.

Due to their high protein content, chicken, lamb, and beef make up a substantial portion of their main ingredients.

Here are the top 5 ingredients used in this particular kibble:

• Lamb Meal
• Brown Rice
• Whole Grain Wheat
• Brewers Rice
• Corn Gluten Meal

Potential harmful ingredients: None.

3. Key Nutrients

Every pet food label must include a guaranteed analysis of the nutrients, according to AAFCO (The Association of American Feed Control Officials) regulations.

It has strict requirements to make sure that a product is in fact complete and balanced for dogs.

This means that complete and balanced diets must contain the minimum amount of all of the nutrients necessary for dogs, which is also indicated in the “guaranteed analysis.”

The analysis must validate minimum crude protein and crude fat percentages as well as maximum crude fiber and moisture percentages.

The tables below will show you the data from the two brands.

Take note: When comparing dog food nutrients percentages, you should remove the amount of moisture to make it a more even comparison.

This is also referred to as calculating its dry matter basis (use this calculator).

This approach is a more accurate way to understand the true nutrient contents of dog food, instead of just relying on the number on the label (which is an ‘as-fed’ basis).

3.1 Purina Pro Plan vs Hills Science Diet dog food nutrients comparison – Guaranteed analysis

Crude protein

Protein is necessary for a dog’s diet to be healthy and well-balanced.

Their bodies need it for a variety of functions, such as the development and maintenance of muscles and other tissues.

It is essential for the growth of new skin, muscle, and hair cells among other things.

Additionally, it aids in the production of hormones and enzymes, two essential physiological elements.

It boosts immunity and releases energy as carbs do.

Dogs can synthesize about half of the 22 amino acids required to make proteins, but the other half must be obtained through food, so it’s crucial to choose a food that has the right quantity of proteins.

In this category, Purina Pro Plan has the advantage of Hills Science Diet, and in fact, close to 30% is desirable for most adult dogs.

Crude fat

Fat provides energy and aids in the formation of supple skin and coat and it is required for the proper absorption of other nutrients.

The fat-soluble vitamins A, D, E, and K are transported by fat, plus it aids in the digestion of vitamin D, which is required for the body to utilize calcium.

It supports a healthy nervous system, brain, liver, blood, skin, and hormone function by keeping cells strong.

Finally, fat protects vital organs from injury and aids in the regulation of body temperature.

Only if you allow your dog to eat excessively and consume too many snacks and not give it enough exercise will fat become an issue.

The amount of fat in both formulas is very similar and is in the right range. You should not be considering more than 20% for most dogs.

Crude fiber

Fiber helps to create solid, well-formed stools and encourages regular bowel movements by increasing mass and absorbing additional water.

Furthermore, fiber aids in the maintenance of a healthy intestinal pH balance, which inhibits the growth of potentially harmful bacteria in your dog’s digestive system.

Lastly, it improves their digestive system’s health and makes them feel satisfied, which may curb their desire and prevent overeating.

Both formulas have fiber content on the low side, especially Hill’s. It is recommended for dogs have between 2% to 4% of fiber in their diet, and not exceeding 6% unless it has specific needs.

4. Range of Formulas

When it comes to the range of formulas available, both companies excel in this department.

There are wide-ranging products that cater to different life stages, and sizes, as well as those that require special diets such as for sensitive skin or weight management.

While this is not as important a criterion as the others, having a variety of products makes it easier for you to find what you need, and your dog will find it easier to adapt to them.

Here are a couple of the most popular options from each company.

5. Product Safety and Recall History

You should always be aware of the safety and recall history of your pet’s food.

This is especially important as you want to know that your money isn’t going to a company that has had any major issues in the past.

And obviously, we need to know what we are feeding our dogs is safe!

I try to update this section as much as possible, but if you find anything amiss, you may double-check on the FDA’s site or its archives for accuracy.

Purina Pro Plan

In March 2016, a few varieties of Pro Plan wet dog food sold in tubs were recalled because of inadequate vitamin/mineral levels.

Hill’s Science Diet

Hill’s Science Diet had a few recalls in its history, with the most recent one happening in 2019 for elevated levels of vitamin D.

This affected its wet dog food only.

6. Price

Although price is important, it shouldn’t be the only thing you consider.

The price of a product is a good indicator of quality and quantity, but not everything with a low price tag is good for your dog.

I’ve seen some brands that are cheaper than others because they use fillers or cheaper ingredients, which can cause health problems down the line.

So if you want something that will last longer and provide more nutrients, then maybe it’s worth investing a bit more in a reputable brand.

The table below shows the price per pound for the options discussed in this article:

In Conclusion: Purina Pro Plan vs Hills Science Diet Dog Food Comparison

When it comes to choosing between the two dog food brands, my personal preference is Purina Pro Plan.

Although both brands make excellent products that you can feel confident feeding your dog, Purina has a more well-rounded product in my opinion.

Quick note: My personal choice for dog food now is Ollie fresh dog food. Find out what’s good about Ollie here.

Remember this: each dog is different and there is no one size fits all dog diet in this world.

Always consider your dog’s breed, activity levels, and allergies, and this should put you on the right course.