While the history of Hill’s dates back to 1939, the Science Diet product line was officially introduced in 1968.

Hill’s Science Diet functions as the wellness and lifestyle nutrition division of Hill’s Pet Nutrition. Its products are designed for pets that are generally healthy but have varying nutritional requirements based on factors such as:

• Age
• Size
• Breed
• Activity level
• Weight-management needs
• Digestive needs
• Skin and coat needs
• Reproductive or life stage
• Other specific wellness considerations

The brand’s fundamental premise is that pet food should be formulated according to animal nutrition science rather than consumer food trends. Hill’s states that its nutritional philosophy is science-led, emphasising research, ingredient selection, clinical evaluation and veterinary expertise.

In essence, Science Diet provides everyday nutrition designed around the biological and nutritional needs of dogs and cats. This differs from Prescription Diet, which focuses on therapeutic nutrition for pets with diagnosed diseases or medical conditions.

Early beginnings

The origins of Hill’s trace back to 1939 and a German Shepherd guide dog named Buddy. When Buddy developed kidney disease, his owner, Morris Frank, consulted veterinarian Dr Mark L. Morris Sr. Dr Morris believed nutrition could play a vital role in managing the dog’s condition.

Together with his wife, Louise Morris, Dr Morris developed a special diet for Buddy in their home kitchen. This experiment evolved into a broader approach to veterinary nutrition. Consequently, Hill’s did not begin as a conventional consumer pet food company; its foundations lie in veterinary medicine and nutritional intervention. This early work eventually led to the development of therapeutic foods and, later, the Science Diet range.

Development of Science Diet

Dr Mark Morris Sr. focused on using nutrition to assist animals with medical issues. His son, Dr Mark Morris Jr., subsequently expanded this work, observing a need for consistently manufactured, high-quality food for healthy animals, particularly within research and veterinary settings. This concept became the basis for Hill’s Science Diet.

According to company records, Science Diet was introduced in 1968 through veterinarians and pet professionals. This established two complementary pillars of Hill’s nutrition:

• Hill’s Prescription Diet: Therapeutic nutrition for specific health conditions.
• Hill’s Science Diet: Everyday nutrition for healthy pets and specific wellness or life-stage requirements.

This distinction remains central to understanding the company’s portfolio today.

Acquisition by Colgate-Palmolive

A significant milestone occurred in 1976 when Colgate-Palmolive acquired Hill’s Pet Nutrition. This integrated Hill’s into a large multinational consumer-products corporation while allowing it to continue operating as a specialised pet nutrition business. Today, Hill’s Pet Nutrition is a key part of Colgate-Palmolive’s portfolio and one of its major businesses outside traditional oral-care and personal-care categories. Colgate-Palmolive describes Hill’s as a global leader in pet nutrition and veterinary recommendations.

Meaning of “Science Diet”

The name Science Diet reflects the brand’s market positioning. Rather than marketing itself around concepts such as “natural”, “ancestral”, “grain-free”, “holistic”, “raw” or “organic”, Hill’s emphasises scientific formulation and nutritional research. The company states that its formulas are developed by teams comprising veterinarians, nutritionists and food scientists, using research to determine nutrient combinations and requirements.

Hill’s currently employs more than 220 veterinarians, qualified nutritionists and food scientists globally 1. This scientific focus is considered the brand’s most defining characteristic.

Product philosophy

Science Diet products are formulated on the premise that no single diet is ideal for every dog or cat. Nutritional needs vary significantly; for instance, a puppy requires different nutrients compared to a senior dog, and small breeds have distinct needs compared to large breeds. Accordingly, the portfolio is categorised as follows:

Life-stage nutrition

Formulas designed for specific developmental stages, including puppies, adult dogs, senior dogs, kittens, adult cats and senior cats. Notably, in 2017, Hill’s introduced Science Diet Youthful Vitality, which later transitioned to Science Diet Senior Vitality 3.

Size-specific nutrition

Dog formulas tailored to body size, covering small/toy breeds, medium dogs and large breeds.

Weight management

Nutrition intended to help pets maintain or achieve a healthy body weight.

Digestive health

Products emphasising digestive function and gastrointestinal support.

Skin and coat

Formulas providing nutritional support for healthy skin and coat condition.

Specialised nutritional needs

Products targeting specific requirements that do not constitute a diagnosed disease.

The exact product lineup varies by country and evolves over time.

Dog food

Dogs represent one of the two primary categories for Science Diet. The range encompasses multiple formats and nutritional profiles, including dry kibble, canned/wet food, treats, specialised formulations and newer refrigerated products.

A notable recent development is Hill’s entry into the fresh/refrigerated dog-food category. In June 2026, Hill’s announced Science Diet Single Protein Dog Food Rolls, with retail availability commencing in July 2026. Initial recipes include Chicken & Brown Rice, Beef & Carrot, and Lamb & Pumpkin. Hill’s describes these as complete and balanced foods for healthy adult dogs, gently steam-cooked and formulated around single animal-protein recipes. This marks an expansion of Science Diet beyond traditional dry and canned formats.

Cat food

Cats constitute the other major focus of Science Diet. The feline portfolio includes nutrition tailored to various life stages, body sizes, activity levels, weight-management goals, digestive requirements, skin and coat needs, and general wellness. Hill’s applies the same core philosophy to cats: formulating nutrition around feline biology rather than producing a generic all-purpose food.

Research is central to Hill’s corporate identity. The company operates the Hill’s Pet Nutrition Center in Topeka, Kansas, where veterinarians, nutrition specialists and scientists conduct research and product development. Hill’s states that its scientists publish more than 50 research papers and textbook chapters annually and collaborate with veterinary schools and scientific institutions.

Key research areas include:

• Clinical nutrition
• Digestive health
• Pet microbiome
• Weight management
• Ageing
• Nutrient metabolism
• Ingredient functionality
• Palatability
• Pet biology

A major research focus is the pet microbiome—the community of microorganisms in the gastrointestinal tract and their relationship with health. Hill’s has developed nutritional technologies in this area, including ActivBiome+ formulations 2.

Veterinary professionals are integral to Hill’s business model and brand identity. Science Diet is commonly positioned through veterinary clinics, veterinary recommendations, pet specialty retailers and online pet stores. Hill’s currently positions Science Diet as part of its everyday wellness portfolio, complementing the therapeutic focus of Prescription Diet.

Hill’s also states that Science Diet is the #1 recommended brand by U.S. veterinarians. This is a company claim and should be understood as a marketing and brand-positioning statement rather than an independent universal ranking.

Understanding the distinction between Science Diet and Prescription Diet is essential.

Science Diet is not merely a lower-tier version of Prescription Diet; they serve fundamentally different purposes.

Hill’s emphasises selecting ingredients based on nutritional function rather than consumer appeal alone. Ingredient selection begins with understanding the specific nutritional needs of dogs and cats, followed by choosing combinations intended to deliver those benefits.

Consequently, marketing focuses on the pathway of nutrients → biological function → health outcome, rather than ingredient name → consumer perception. Discussions typically centre on nutrients such as protein, essential fatty acids, vitamins, minerals, antioxidants, prebiotics and fibre, rather than fashionable ingredient lists.

Hill’s places significant emphasis on manufacturing quality and safety, stating that its standards are modelled on those used by human-food manufacturers. The company asserts that its pet foods meet or exceed nutrient profiles and manufacturing guidelines established by organisations including AAFCO and WSAVA. Evaluation criteria encompass nutritional adequacy, nutrient balance, manufacturing controls, formulation and feeding requirements, rather than solely ingredient appeal.

Due to its extensive nutritional research, Hill’s research practices have occasionally attracted public discussion. The company states it uses dedicated pet partners for product testing and research at its Pet Nutrition Center, describing these animals as receiving dedicated care, housing, exercise and veterinary attention. Hill’s presents this model as an animal-welfare-oriented scientific programme rather than conventional laboratory animal research. However, consumers may hold differing ethical views regarding feeding trials and controlled nutritional studies.

Hill’s is an international brand operating through Hill’s Pet Nutrition and Colgate-Palmolive. A notable regional difference exists in branding: in the United Kingdom and parts of Europe, the everyday-wellness line has historically been marketed as Hill’s Science Plan rather than Science Diet.

Consumers may therefore encounter:

• Hill’s Science Diet: Primarily in the United States and select other markets.
• Hill’s Science Plan: Primarily in the UK and certain European markets.

Despite the naming variation, the underlying organisation and science-led positioning remain consistent.

The corporate structure is organised as follows:

• Colgate-Palmolive (Parent Company)
• Hill’s Pet Nutrition (Business Unit)
• Hill’s Science Diet (Everyday nutrition brand)
• Hill’s Prescription Diet (Therapeutic nutrition brand)

Science Diet is a principal product brand within Hill’s Pet Nutrition, not the name of the entire company.

1939 — The beginning

Dr Mark Morris Sr. develops a special diet for Buddy, a guide dog suffering from kidney disease.

1940s–1950s — Veterinary nutrition develops

Morris’s work evolves into specialised therapeutic pet foods and the foundation of the Hill’s business.

1951 — Research expansion

Dr Morris establishes a research laboratory in Topeka, Kansas.

1968 — Science Diet introduced

Hill’s Science Diet is launched for healthy pets through veterinarians and pet professionals.

1976 — Colgate-Palmolive acquisition

Colgate-Palmolive acquires Hill’s Pet Nutrition.

1980s–2000s — Portfolio expansion

Hill’s expands its life-stage, therapeutic and specialised nutrition portfolios.

2010s — Microbiome and advanced nutrition

Research increasingly focuses on microbiome health and advanced nutritional science.

2017 — Senior nutrition

Hill’s introduces Science Diet Youthful Vitality, later becoming Science Diet Senior Vitality 3.

2019 — Brand relaunch

Colgate-Palmolive reports the relaunch of Hill’s Science Diet 4.

2026 — Fresh food expansion

Hill’s launches Science Diet Single Protein refrigerated dog-food rolls, marking its entry into the fresh dog-food category.

Hill’s Science Diet is defined by several core characteristics:

• Science-first: The primary differentiator is the emphasis on nutritional science and research.
• Veterinary credibility: Strong, deliberate relationships with veterinarians and veterinary nutrition.
• Life-stage nutrition: Products differentiated by age, size and nutritional requirements rather than a one-size-fits-all approach.
• Clinical heritage: Roots in veterinary therapeutic nutrition distinguish it from conventional pet food companies.
• Mainstream premium positioning: Positioned in the premium/upper-mainstream segment rather than as an ultra-luxury boutique product.
• Global corporate backing: Ownership by Colgate-Palmolive provides substantial resources and international distribution.

Hill’s Science Diet occupies a distinct position compared to other pet food categories:

• Traditional supermarket pet food: Focuses on affordability and broad consumer appeal.
• Boutique/natural pet food: Emphasises ingredient sourcing, “natural” positioning, novel proteins or specific dietary philosophies.
• Hill’s Science Diet: Emphasises research, nutritional formulation, veterinary expertise and measurable nutritional objectives.

The brand’s distinctive proposition is that food is designed first around nutritional science, then marketed based on the resulting health benefits. Whether it is the optimal choice depends on individual factors including species, age, body condition, activity level, health status, preferences and veterinary advice.

As of 2026, Hill’s continues to expand beyond traditional dry and canned formats. The launch of refrigerated Science Diet Single Protein Dog Food Rolls in the U.S. in July 2026 demonstrates an adaptation of its science-led nutrition positioning to align with consumer preferences for fresh and refrigerated pet food. These products are designed to provide complete and balanced nutrition while supporting digestibility, skin and coat health, and overall wellbeing. Despite this evolution, the company’s fundamental identity remains rooted in nutrition backed by veterinary and scientific research 5.

Hill’s Science Diet is best understood as a science-driven, veterinarian-oriented pet food brand with roots in clinical veterinary nutrition. Its history is distinctive, originating from a veterinarian’s attempt to manage a sick dog’s condition through nutrition in 1939, which evolved into Hill’s Pet Nutrition and the subsequent creation of Science Diet for healthy pets in 1968.

Today, the brand rests on four pillars:

1. Scientific research: Extensive investment in veterinary and nutritional science.
2. Nutritional specialisation: Differentiated formulas for various ages, sizes and needs.
3. Veterinary relationships: Deep integration with veterinary professionals.
4. Global scale: International distribution under Colgate-Palmolive.

Hill’s Science Diet serves as the everyday-wellness arm of Hill’s science-led nutrition system, complementing the therapeutic arm represented by Hill’s Prescription Diet. From a 1939 veterinary experiment, it has grown into one of the world’s most recognised science-oriented dog and cat food brands.

1. Science Diet
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4. Adult Chicken & Barley Recipe Dog Food | Hill’s Science Diet
5. Hill’s Science Diet | Hill’s Pet US