Hill's Science Diet

Hill's Science Diet scores in the upper tier on Chowmark. Founded in 1939 by veterinarian Dr. Mark L. Morris Sr. — who developed the first prescription kidney diet for a guide dog named Buddy — Hill's is now owned by Colgate-Palmolive and is one of the most widely recommended brands in veterinary practice globally.

The brand has recorded one lifetime recall, and it is significant: on January 31, 2019, Hill's Pet Nutrition issued a voluntary recall of select canned dog foods due to potentially toxic levels of Vitamin D. The recall was expanded twice — in March 2019 and May 2019 — ultimately covering 33 varieties of Hill's Science Diet and Hill's Prescription Diet canned dog food. The aftermath included a consolidated class-action lawsuit (In Re: Hill's Pet Nutrition Inc. Dog Food Products Liability Litigation, case number 2:19-md-02887, U.S. District Court, Kansas City) involving approximately 300 plaintiffs alleging dogs were seriously injured or died from Vitamin D toxicity. The FDA closed its investigation in 2020. Hill's has not had a confirmed recall in the six years since. That record matters, but so does the 2019 event — any pet owner making a feeding decision deserves to know it.

Hill's Science Diet meets WSAVA Global Nutrition Guidelines. The brand employs board-certified veterinary nutritionists, conducts AAFCO feeding trials, and has an extensive body of peer-reviewed research behind its formulas. The Prescription Diet line — developed specifically for disease management — is the most clinically validated pet food product line in the world. That evidence base is the brand's primary strength.

The WSAVA note worth disclosing: Hill's Pet Nutrition is one of the funding sources for WSAVA's Global Nutrition Committee, alongside Purina Institute and Royal Canin. That is a real conflict of interest. It does not invalidate WSAVA's guidelines, but it is context that Chowmark discloses on its methodology page.

The bottom line: Hill's Science Diet is a genuinely evidence-based brand with strong veterinary credibility and one major safety incident on its record. The 2019 recall is resolved, but it should be part of any honest evaluation. For pet owners who want WSAVA-compliant nutrition with a strong research foundation, Hill's remains one of the top recommendations — with eyes open about the 2019 event.