Hill's Dog & Cat Food Reviews

It Started With a Blind Man's Guide Dog

In 1939, a young blind man named Morris Frank brought his German Shepherd guide dog, Buddy, to veterinarian Dr. Mark Morris Sr. in Topeka, Kansas. Buddy was dying of kidney failure, and Frank asked if anything could be done. Dr. Morris believed he could manage the disease through nutrition alone. He and his wife Louise formulated a special low-protein, low-mineral diet in their home kitchen — and Buddy recovered. That recipe became Prescription Diet k/d, first commercially canned in 1948 through a partnership with Burton Hill of the Hill Packing Company. It was the world's first veterinarian-formulated therapeutic pet food. Dr. Morris's son, Mark Morris Jr., later expanded the concept into everyday wellness nutrition, launching Science Diet in the 1960s. Colgate-Palmolive acquired Hill's in 1976 and turned it into a global operation now sold in over 80 countries.

Two Brands Under One Roof — and They Are Not the Same

Hill's operates two distinct product lines that serve very different purposes, and confusing them is a common mistake among pet owners:

Prescription Diet – therapeutic nutrition designed to manage specific clinical conditions such as kidney disease (k/d), urinary issues (c/d), obesity (Metabolic), joint problems (j/d), gastrointestinal disorders (i/d), and even cancer support (ONC Care, launched in 2023). These require a veterinary recommendation and are sold primarily through vet clinics. With over 60 formulas, this is the line that vets reach for when diet is part of the treatment plan.
Science Diet – everyday wellness nutrition for healthy pets, organised by life stage, breed size, and specific needs like sensitive stomach, oral care, or weight management. Over 50 formulas are available. This is the retail line you will find at pet stores and online.

Both lines are formulated by a team of over 220 veterinarians, food scientists, and nutritionists at the Hill's Pet Nutrition Center in Topeka, and the brand's Small Animal Clinical Nutrition textbook is still used in veterinary schools worldwide.

The 2019 Vitamin D Recall — Hill's Worst Moment

Any thorough Hill's review must address the 2019 recall, which was the most damaging incident in the brand's history. In January 2019, Hill's voluntarily recalled 25 varieties of canned dog food after a pet owner reported vitamin D toxicity. The FDA then requested additional testing, and the recall expanded to 33 varieties — roughly 675,000 cases, or over 17 million individual cans — across 78 countries. Multiple dogs became seriously ill and some died from kidney failure caused by the excess vitamin D. Hill's blamed a supplier error in a vitamin premix and settled a class action lawsuit for $12.5 million in 2021. The company has since implemented stricter Certificates of Analysis requirements for all incoming ingredients. It was a serious failure of quality control from a brand that built its entire identity on clinical precision, and while Hill's has recovered commercially, some pet owners and veterinarians have not fully restored their trust.

The Ingredient Debate: Clinical Nutrition vs Clean Labels

Like Royal Canin, Hill's follows a nutrient-first philosophy rather than an ingredient-first one. This means you will see items like chicken by-product meal, corn gluten meal, brewer's rice, and powdered cellulose on ingredient lists — ingredients that are nutritionally functional but unpopular with consumers who prefer whole-food labels. Hill's argues, with significant veterinary backing, that what matters is the nutrient profile of the finished product, not the consumer appeal of individual ingredients. Critics counter that a company generating $3.7 billion in revenue could source more recognisable ingredients without sacrificing nutritional precision. Both perspectives have merit, and the right choice depends on whether you prioritise clinical evidence or ingredient transparency. For pets with diagnosed medical conditions, Prescription Diet remains one of the most effective dietary tools available. For healthy pets, Science Diet is a solid, vet-endorsed option — but buyers who want a cleaner label at a similar price point have alternatives worth considering.