Pet food company visits: Hills Pet Food, Topeka, Kansas

Pet food company visits: Hills Pet Food, Topeka, Kansas

As many of you are aware, a small number of the Canine DCM Admin Team recently returned from a visit to Hill’s headquarters in Topeka, Kansas. Representing the group was Dr. Kim Skibbe, James Cohen, Dr. Genevieve Bisson, Dr. Catherine Cole, and one of our Support Group Admins and affected owner, Trisha Brenner. Our primary goal in visiting pet food companies is to gain a better overall understanding of the steps that are taken in developing and manufacturing pet food.  The Hill’s visit allowed us to observe firsthand the practices that Hill’s employs in producing their diets. We were also given clarification as to the cause of the February 2019 Vitamin D associated recall.

Overview of the Day’s Events

Our morning consisted of a symposium focused on reviewing what we currently know about Nutritionally-mediated Dilated Cardiomyopathy (NM-DCM) and the nutritional concerns that are at the forefront of both the veterinary and pet food manufacturing communities. We were joined by a number of Hill’s professional and veterinary staff, including: 

  • Maria Debernardi, DVM, PhD, Worldwide Director of Professional and Veterinary Affairs
  • Jolle Kirpensteijn, DVM, PhD, Dipl. ACVS, Dipl. ECVS, Chief Professional Veterinary Officer
  • Dave Baloga, BS, Vice President of Science & Technology
  • Kathy Gross, MS, PhD, PAS, Dipl. ACAN, Worldwide Director of Clinical Nutrition and Claims. 
  • Jennifer Radosevich, PhD, Worldwide Director of Research
  • Becky Mullis, DVM, Dipl. ACVN, Associate Manager of Scientific Affairs and Adjunct Faculty at Kansas State University College of Veterinary Medicine
  • Vicky Ograin, MBA, RVT, VTS (Nutrition), Specialist, Global Education in the Global Professional Veterinary Affairs


We were also joined by three independent experts, Nicole LeBlanc, DVM, Dipl. ACVIM (Cardiology), Clinical Assistant Professor of Cardiology at Oregon State University Carlson College of Veterinary Medicine, Julie Churchill, DVM, PhD, Dipl. ACVN, Associate Professor in the Department of Clinical Sciences at the University of Minnesota College of Veterinary Medicine Veterinary Medical Center, and Greg Aldrich, PhD, Research Associate Professor and Pet Food Program Coordinator at Kansas State University, each of whom presented on DCM and pet nutrition:

  • Dr. LeBlanc provided an overview of both genetic DCM and NM-DCM and the various treatments for each condition, as well as a case study of a patient diagnosed with NM-DCM and subsequent improvement with treatment. Oregon State is currently undertaking research comparing echocardiogram parameters of dogs on traditional diets vs dogs on grain-free diets.  
  • Dr. Churchill discussed the evolution of grain-free diets and what brought about the current crisis we are facing.  She calls it a “perfect storm” of circumstances and that a variety of factors were at play, many of which have already been discussed in the group (see her diagram below which she was kind enough to share with us).  One key point that she highlighted, and which has not been discussed thoroughly within the group, is the “Food Safety Modernization Act”. This change in regulation has led to more scrutiny of pet food, hence more recalls.  This likely is making pet food safer, but the negative perception of increased “recalls” may leave consumers feeling less safe.
    Dr. Churchill also had a key suggestion for veterinarians: make SPECIFIC diet recommendations for your clients. Just naming brands isn’t enough. Help them choose formulas and give instructions.
  • Dr. Aldrich formulates for over 100 pet food companies. He spoke about the challenges of this, including estimating final nutrient outcomes. Ingredients vary by supplier; the same ingredient from the same supplier may even vary throughout the season so the formulator must take this into consideration. He discussed nutritional key points in greater detail, including the bioavailability of known proteins and grains, as well as the significant lack of knowledge we have about the digestibility of many of the “exotic” ingredients, and the role that anti-nutrients and oligosaccharides may have in pet nutrition.  We did ask Dr. Aldrich some candid questions about his previous recommendations for pulse legumes in pet food and whether he would modify those recommendations now. There were multiple ideas exchanged but suffice it to say it is difficult to know limits when we do not definitively know if there is a deficiency, an anti-nutrient, or other unknown factors. He even mentioned the possibility that change in agricultural practices should be considered as a possible cause (we take this to mean practices or environmental changes that might influence a nutrient or toxin we are not currently measuring).


Our afternoon consisted of an extensive tour of the Hill’s Research Facility and included observation and/or discussion of:

  • Production Floor. We were given an overview of the canning and extruding equipment used to manufacture the diets intended for feeding and/or clinical trials. A unique feature was their mini-extruder, built exclusively by Hill’s and capable of producing a 50lb batch (the extruders used for producing trial-associated batches produce 2000lb of kibble and their main production extruders produce 10,000lb batches for reference). The mini-extruder allows Hill’s to quickly analyze the finished product of any new, or altered, formula for up to 150 different nutrients.
  • Research Center Here we were given an overview of Hill’s main areas of research: Nutrigenomic (how nutrients can affect gene expression), Nutrigenics (how genes can affect how a diet works), and the GI microbiome (how nutrition can support and maintain healthy gastrointestinal microflora and the subsequent effects that can have on overall health).
  • Canine Research Housing Facility.We were able to observe their research dogs in their regular environment. Dogs were housed in groups and as pairs of “best friends”. Size and energy level of dog was taken into account in forming housing groups.  Many, but not all, of the dogs were beagles or similar medium-sized dogs. The dogs have access to both indoor and outdoor areas and are given ample opportunities for both rest and play. At any given time, 1-2 employees were continuously interacting with the dogs in positive ways (petting, playing, cuddling, etc.). Hill’s also recently announced they will be building an additional facility focused specifically on small and toy breed research.
  • Feline Research Housing Facility. Cats were housed in groups of up to 13 cats. For cats who do not tolerate group housing, there are separate areas where they can interact with a smaller number of cats. All cats have access to significant amounts of natural sunlight, cat trees, elevated walkways, toys, cat oriented television and other forms of environmental enrichment. The cats we observed were comfortable with one another and well socialized with humans. Staff members were also observed interacting with various cats within each housing group.
  • Veterinary Facility. Hill’s employs 3 veterinarians to provide medical care for their research animals. In addition to basic preventive care, the animals also receive regular dental care. We met Dr. Scott Mickelsen who is board-certified in laboratory animal medicine and discussed some of Hill’s animal welfare policies with us. He also discussed that animals are never intentionally given a disease, however, they do study animals with naturally-occurring diseases. They have a surgery center to treat any injuries and to perform routine procedures such as spays, neuters and dental care.
  • Formulation. One of the most important considerations for Hill’s in formulating a new diet is sourcing as formulas are built around high-quality, consistent ingredients. Nutrients, rather than ingredients, drive their formulaic choices.
    New product development steps are:

    • concept of the diet
    • which nutrients or components will meet that concept
    • identifying various combinations of ingredients that meet the nutrients identified, and determining which of those ingredient combinations will work best for the product.

Approximately half of the researchers are focused on new product development and half are focused on maintaining quality of current products.  

  • Feeding Trials. Trials are conducted in a manner to reduce stress as much as possible. For example, in the event that 24-hour stool collections are required, those animals are housed separately for a short period of time but still allowed access to enrichment, natural light, and the outdoors. For palatability trials, animals are given an option of which food to eat and, in the case of dogs, portions are controlled by a scale under the bowl so as not to allow the dogs to become overweight.
  • Scent Research.Aromatics play a huge role in palatability and Hill’s even has a process by which human noses are employed to detect specific aromatics that have been shown to be most appealing to cats and dogs as part of their formula development.
  • Future Research in NM-DCM. A team from EmbarkVet met with us at the end of the day to announce a new joint research project with Hill’s in which the entire genome of 1000 affected dogs will be analyzed and compared to look for possible commonalities. Given Hill’s area of expertise in nutrigenomics and nutrigenetics, this research may help to forward the understanding of NM-DCM, including why it occurs in certain dogs and how it may be best treated.

In answer to your questions:

The following are some of the questions submitted by members prior to our trip.  

  1. How much do ingredients fluctuate from the supplier and how is uniformity in nutrients achieved across batches?  Aldrich discussed this as mentioned above. Hill’s staff also discussed the importance of sourcing ingredients and the need to take into account seasonal variability. Some ingredients are known for being relatively consistent whereas others can vary significantly. They were very clear on the importance of accounting for these variabilities in production.  
  2. What measures are in place that maintain compliance with your incoming feedstock quality requirements? There are multiple processes that influence ingredient control and monitoring; multiple team members are responsible for ingredient analysis and variability. It was also mentioned that in the few cases where foods are produced elsewhere (such as the pouch style packaging that Hill’s does not produce in its own plant), the manufacturer is required to use Hill’s suppliers or do additional testing to show compliance. In one overseas plant, Hill’s brought in much of their own equipment to ensure consistent and appropriate product manufacturing practices.
  3. Why are some formulas “formulated to meet” AAFCO nutrient profiles whereas others have undergone AAFCO feeding trials? When do you choose to perform feeding trials (AAFCO and other) vs use “formulation” to determine nutritional adequacy? We have discussed this in our group a number of times but any time a formula changes, it must undergo a new feeding trial. Foods that are currently undergoing trials cannot say that they have been tested and thus must use the statement that indicates they were formulated to meet AAFCO nutrient profiles. Once the trial is completed and the food is found to be nutritional complete and balanced, the new bags will state that they have undergone AAFCO feeding trials. 
  4. Is ileal digestibility (as opposed to total GI tract) assessed? If so, how? (Inspired by looking at legume inclusion studies and finding where increasing soybean meal decreased ileal digestibility and increased large intestine digestibility – indicated less amino acids would be absorbed but the end output would be identical). Dr. Aldrich touched on this to some degree. Previously ileal cannulation gave us important information as the ileal digestion of chicken and other popular ingredients. However, more recently, Ileal digestibility is no longer being studied do the invasive nature of ileal cannulation. As a result, we know significantly less about the newer, “exotic” ingredients. This further emphasizes the need to have additional research and testing done when working with such ingredients.
  5. How do you determine which temperature is used in the extrusion process and whether or not there is a negative impact on nutrients, as well as whether or not contaminants are appropriately eliminated? Are all batches and formulas treated in the same manner or can temperatures vary based on the formula?
    Canned food is heated to 250F to kill Campylobacter.  Final temperature of extrusion process varies from 250 to 300 F for a brief period of high pressure.  However, each extrusion includes 90 seconds at 180F as a step to destroy Salmonella.
    Oils, fats, and palate enhancers are often added after the extrusion process.
    Analyzing the nutrient content of the actual diet (after processing) is part of the formulaic process.  
  6. We often get questions about euthanized animals/pets ending up in pet foods. Can you please describe what steps are taken/what standards are in place to prevent that from happening?  Hill’s is very particular about their ingredient sourcing and each supplier is required to provide quality assurances. Hill’s chooses their protein sources based on the quality of the protein provided and all protein sourcing follows US law, which prohibits the use of 4D or euthanized pets in pet foods. Furthermore, it’s important to note that due to our current knowledge of cat and dog DNA, testing for pet DNA is relatively straightforward.  
  7. Can you walk us through the quality control process for one batch of dog food? What is the quality control/safety checks for each ingredient – at the source as well as prior to addition? Hill’s discussed their quality control processes with us and they primarily focus on the early steps of production, namely at the sourcing level. Each raw ingredient supplier is required to meet criteria as set forth by Hill’s. Their goal is to make sure that everything has been checked, and now double or triple checked, at the beginning so as not to waste a 10,000lb batch of food. That’s not to say that testing isn’t done after production, but the bulk of their quality control measures are in the initial, raw ingredient phases.
  8. What changes have been implemented as a result of the Vitamin D recall? All incoming vitamin and mineral premixes now undergo three levels of testing prior to inclusion. One test is done by the supplier, another by Hill’s, and a third test by an independent third party.
  9. How many board-certified veterinary nutritionists (DAVCN, PhD) do you have on staff? We met with no less than 10 PhD or board-certified veterinary nutritionists and that was by no means the entire advanced nutritional staff. 
  10. You outsource a small percentage of your formulas, why and which formulas?  Hill’s outsources some formulas that they do not have the packaging facilities for (particularly some foods that are in pouches.)  The manufacturers are required to use suppliers approved by Hill’s. 

Our overall impressions:

We were very impressed with the manner and seriousness with which our group was received and our concerns addressed. A significant number of staff took time out of their schedules to answer any and all of our questions, and to show us how passionate they are about making both tasty and scientifically sound pet food. Some points that particularly stood out:

  1. Responsible pet food manufacturing takes time, on the order of several years, to get right.
  2. In order for a diet to be “formulated to meet AAFCO nutrient profiles” it must only meet those specific nutrient requirements on paper, at the time of formulation. There is no regulation in place necessitating that nutrient profiles must be met post-production. This was perhaps the single most surprising discovery and absolutely illustrated the need for companies to assume greater responsibility on their own to ensure a diet is truly complete and balanced.
  3. Successful production involves an entire team of experts working together and includes everyone from the employee running the extruder to the scientists formulating the diet, from nutrient profiles and ingredient sourcing to post production analysis and food storage design. 
  4. Sourcing involves so much more than taking into account “local” options. Season must be considered, as well as consistency of the nutrient profiles within the sourced ingredient.
  5. NM-DCM was discussed in great detail and the experts believe that there are multiple factors at play and that all cases are unlikely to fit nicely into a single category.
  6. The emphasis should be placed on nutrients over ingredients, with appropriate and thoughtful sourcing of ingredients to provide those nutrients.
  7. We met many employees during our short visit to Topeka: some that spoke to us briefly and others that discussed questions at length.  We were given the impression that all of these employees have pride in their work and the mission of improving pet nutrition. 


Vitamin D Recall

Hill’s staff spoke candidly with our team about the Vitamin D Recall and series of events that lead to this recall.  It was a human error on the side of the supplier in which extra bags of Vitamin D were added by accident instead of Vitamin E. A checklist noting all additions was required by Hill’s, but, unfortunately, was checked off showing that the correct amounts of both Vitamin D and Vitamin E had been added and that testing on the premix had been performed when, in fact, it had not. In response to this failure, Hill’s now requires three separate tests on all vitamin and mineral premixes, one by the supplier, one by Hill’s, and one by an independent third party. 

When asked why they did not detect the excess Vitamin D in the finished product, Hill’s explained that their quality control is focused very heavily on the front end of production with very stringent requirements in place for all of their suppliers. Their approach to production is to make sure that all is correct going in as it becomes much more problematic to address issues on the post-production side. One could certainly argue that a quality control program that focuses on the supply side should have had more strict, confirmatory testing in place from the beginning. Encouragingly, they are looking at all areas of intake to add other similar additional tests to vitamin/mineral intake. 

Some links provided by Hill’s that may be of interest to readers and help answer additional questions:
Animal Welfare Policy :

Video tours of facilities: