With people treating their pets as members of the family, pet food manufacturers find they have to produce pet food as though it were human food, which—combined with food safety regulations—creates a lot of pressure to stay competitive. In this article, we look at how the growth of consumer demands and regulations is modernizing pet food operations.

Our pets are family

Steve Bain, Festo Corp. industry segement manager—food and beverage, says he worries about the safety of the food he gives his springer spaniel, Bella.

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“There have been countless reports over the past decade of various foods and dog toys that have injured or sickened dogs,” says Bain. “As a consumer, I actively search for reputable brands that I trust (and hope) haven’t outsourced production or ingredients to companies who don’t share this concern.”

The good news is FSMA has forced pet food suppliers to treat pet food products as though they were people food, adds Bain. “I still see a lot of gaps in terms of implementation, but I think it’s moving in the right direction. I absolutely think a small pet food provider can make an impact on the market. Don’t focus on cost—focus on quality.”

What consumers want

“Consumers want high-quality pet food and reliable sourcing of superior ingredients, with a food-safe assurance,” says Tom Barber, Bühler vice president—capital sales. “They also prefer ingredients that zero in on specific health concerns, with protein being a major inclusion.” 

These preferences have led manufacturers to create and test new recipes for specialty pet foods and treats, and to add new processing lines, says Barber. Processors are tuned into advances in food safety, and many are looking for ways to validate that their operations are reaching a level of microbial reduction. 

Bain thinks we’ll start to see more advertising for successful third-party audits. “It wouldn’t surprise me at all to see SQF logos on every pet food bag, along with marketing to educate consumers on the value of that logo. Major retailers are already requiring this, so the next logical step would be making consumers aware of these certifications.”

Being attentive to consumer demands is especially helping smaller, innovative pet food processors to be resilient in the face of competition, says Barber. “From our perspective, pet food manufacturers will survive by continuing to innovate and closely watch trends. We are working with many customers to develop and test new products in our laboratories, which are then scaled up for mass production.” Barber notes that unexpected ingredients like duck, rabbit and alligator—and sustainable, alternate protein products—are generating a lot of interest.

Besides exotic ingredients, packaging is important. Is that 50-pound bag of grain-based kibbles on its way out? “Pet owners today want quality food that is convenient to use and offers single-serve, portion control attributes,” says Jeff Arthur, Allpax technical sales director. And they want simple, single-serve packaging that allows them to prepare meals for their pets quickly and efficiently—and “cleanly.” This has changed the game for wet pet food processors, who must now be capable of handling and processing sophisticated packaging at high rates of speed to keep up with the growing demand, and have the flexibility to process multiple different package types. While the capital to do this may put a crimp on smaller processors, the growing market for high-end, specialty boutique products means consumers are willing to support the specialty producers.

Convenience isn’t the only reason why packaging is important. “Not only is it becoming imperative to have unique packaging to standout in the market, pet owners have also shown they do a great deal of research, and it is critical for packaging to include a listing of all ingredients,” says Ryan Bequette, senior project engineer, Burns & McDonnell, food and consumer products. Much like the food industry overall, pet owners are looking for a wide range of options, including organic and natural pet food. There is so much information now widely available, many consumers base buying decisions on custom nutrition plans for their individual pets, so the information on all packaging must be clear and transparent.

Consumers are looking for cleaner labeling with fewer additives and fresher ingredients (e.g., raw meat addition) as well as gluten-free alternatives, says Sharon Nowak, global business development manager, food and pharmaceuticals, Coperion—EFD Business Unit. One new addition is the use of texturized proteins as meat substitutes. High meat pet food is generally defined as having fresh meat contents of greater than 30%. In some cases, the combination of both low-end animal protein with small amounts of vegetable protein is also used to get the texture and appearance of meat.

Nevertheless, all-natural, clean label, grain-free, raw/fresh and high protein are all growing sectors within pet food, says Lindsay Schroeder, food safety specialist at Dennis Group. This “premiumization” of pet food allows small, specialty batch producers to compete with niche products that cater to new consumer trends. This trend will continue in the foreseeable future since online channels allow direct-to-consumer distribution.

Another important labeling distinction—though it’s been around for some time—is differentiation of nutritional needs for the life cycle of a pet, e.g., puppy/kitten, adult, senior, says Ed Gerken, senior project manager, SSOE Group. Other product categories might address specific nutrition needs (e.g., sensitive skin or stomach, all-natural, weight management and even urinary tract health).

Pet food: Billion-dollar business with premium a big deal

According to a study from The Impetus Agency and published by the American Pet Products Association, U.S. spending for pet food in 2018 was $30.3 billion, up 4.3% from 2017’s total of $29 billion. Spending on pet food continues to make up the majority of dollars spent in the industry, with premium dog food accounting the most frequent type of food purchased, followed by generic and natural food, says Bob Vetere, APPA president and CEO.

The pet food plant of the future will use automation to get the most out of equipment and maximize overall equipment effectiveness. In fact, automation will be key to staying competitive.

Consumer demands shape equipment design

With the interest in increasing raw meat in pet food content, problems arise in at least two areas. If the meat is to be kept raw, it needs some kind of kill step before going out the door. However, increasing raw meat levels in kibbles brings its own set of unique problems, especially in the extruder operation.

The focus on raw meat in pet food is driving special demands on extrusion and other processing equipment, says Walker Mattox, president of GraySolutions. It is also putting a new demand on cleanability for all associated equipment. Pet food manufacturers and their equipment suppliers must pay more attention to sanitary design requirements of these new systems while also looking at sizing their equipment to handle larger inclusions of raw meat as consumer demands evolve. These changing demands also bring requirements for more sophisticated automation systems to tightly control the addition of raw meat directly into the kibble process. Equipment used to transport and package kibble must also be designed to handle kibble with more raw meat to ensure that the finished product in stores meets higher quality standards.

Twin-screw extruders have the processing advantage over single screws for high meat pet food extrusion, due to the improved mixing and kneading capabilities, says Coperion’s Nowak. Processing high meat levels requires a reduction in throughput rate relative to classic dry food. 

The challenge for the extruder manufacturer, adds Nowak,  is to develop methods that allow the higher throughput rates needed to process the high meat slurries within the extruder, while still maintaining overall physical size. Coperion’s newest twin-screw extruder, the ZSK Mv PLUS, is suited to achieve these requirements. The combination of its deeply cut screws, resulting in a higher free volume (Do/Di of 1.8) and its ability to run at speeds up to 1800 rpm result in higher capacities of difficult high meat products, all within the same footprint.

Bühler’s extrusion laboratory recently ran tests to determine how high meat additions affect the extrusion process, and the results were presented at a recent Pet Food Forum. The lab ran experimental trials with recipes ranging from 20% to 85% meat content (as a percentage of a dry recipe). The goal was to establish a stable process for meat additions, investigate the possibilities for preheating of meats and pretreatment of moisture, understand limitations on water content in the extruder and the influences on product shape, color and kibble texture.

The studies were conducted using a twin-screw extruder and gravimetric dosing system. They also included a speed mix conditioner with steam addition, a density control system and dosing system with high pressure pump for the fresh meat (from 75% down to 50% moisture in the meat), and a belt scale for the meat concentrate (40% moisture). Bühler’s studies also applied tube heat exchangers with scrapers for the preparation of the meat, along with a standard ring die with pins and a standard screw configuration for pet food. 

Results were not surprising. The main limitation was the moisture content in the extruder. When high, product began to stick, and cutting and handling were difficult. With higher meat content, color of the kibbles changed and the bulk density resulted in heavier and less expanded products. Finding a suitable formula was a challenge. 

In conclusion, Bühler found that double extrusion on existing lines offered good results for the same product, even with high fresh meat additions. 

Ingredient changes to kibble to include a higher protein content will affect the viscosity of the extruded mixture, and in many cases, existing mixers and extruders will be able to handle emulsions of varying thickness, says Dennis Group’s Schroeder. However, piping may require retrofitting for heat tracing to ensure a consistent quality and viscosity is maintained during processing.

The issues caused by using more raw meat and less starch in the kibble extrusion process are not issues for other processes, and SSOE’s Gerken offers an alternative. “Today, there is a demand for healthier options that avoid the loss in enzymes, minerals and vitamins that occur in the extrusion process used to make kibble. Another option these days is oven-baked kibble that tends to retain the vitamins in the food where those vitamins are lost in the extrusion process.”

Wet pet food ingredients are evolving, also placing new demands on the retort process. More unique and customized retorting processes are needed for today’s higher quality products to maintain particulate integrity, in-container visual appearance and taste, says Allpax’s Arthur. This requires updated retorting and/or control delivery technology. The same can be said for handling today’s more specialized shelf-stable pet food packaging, such as aluminum trays, plastic bowls/cups and pouches.

Food safety issues

“I’m seeing a lot of change on the primary packaging part of the process, but the secondary and tertiary packaging part of the industry still hasn’t adapted (in general) to the food industry,” says Festo’s Bain. FSMA specifically calls out that secondary packaging equipment needs to be designed so that it is easily cleanable (not that it is actually cleaned). There is a huge gap in the current market for cleanable secondary packaging equipment. “I hope secondary packaging companies are paying attention because the market is there!”

One improvement to primary packaging comes in the area of modified atmospheric packaging, though it’s not in the packaging itself, but the ability to detect if there’s a leak in the MAP package on the line. “MAP only works if your package is properly sealed, keeping the protective gas inside,” says Joshua Friesz, Emerson global product manager, Rosemount food and beverage and life sciences. “Assuring freshness in every package that leaves a packaging line is challenging, however, since you don’t want to compromise speed and efficiency for package testing.” 

The traditional method for testing packaging is to take an occasional grab sample, but the obvious downside to this approach is that some leaking packages may still sneak through, says Friesz. Featured in FE’s December 2018 Engineering R&D column, Emerson’s Rosemount CT4215 leak detection system has the capability to test every package on the line to be certain each is properly sealed. When the system detects a leaking package, it is ejected from the line without slowing down production.

Further upstream, processing equipment needs to be designed to be cleaned as well, says Burns & McDonnell’s Bequette. “As raw meat continues to increase in demand, it is imperative for equipment design and specifications to be properly reviewed to make sure all equipment can be thoroughly cleaned and will not harbor points for microorganisms to grow.”

For a shelf-stable product, Allpax’s Arthur suggests that the retort process for each product/package combination should be designed to provide the appropriate level of sterilization, one that is safe and ensures quality and nutritional value. 

Extruders, cookers, HPP and scraped surface heat exchangers are all means to ensure that raw meat products are prepared under controlled conditions to reduce biological issues, says Jeff Matis, CRB project director. This equipment and a raft of other types are now designed to control not only the process conditions and contact surfaces’ sterility during processing, but also the conditions, environment and any source of contamination post-processing until safely sealed inside whatever means of finished packaging is desired. Some packaged material will undergo thermal or other form of processing such as HPP to ensure post-processing sterility no different than human food products. 

“HPP is most widely used for the inactivation of pathogens in the raw materials of pet food,” says Errol Raghubeer, senior VP, JBT/Avure. After HPP, the product can be sold as refrigerated or frozen pet food, or sent to a clean room to be formed into shapes such as nuggets, bones, biscuits, etc. The “shaped” pathogen-free product can then be sold refrigerated or frozen, or further dehydrated by heat or freeze drying, says Raghubeer.

“The key aspect to all of this equipment for the pet food industry is that there is now little difference between the equipment and the process environment for either pet or human consumption,” adds Matis.

“Bacteriophage has been the most common biological kill step up to this point, and use of HPP technology is still rather new in the food industry,” says Dennis Group’s Schroeder. “HPP technology is promising since there is no addition to the product, only the use of pressure. HPP requires a large upfront expense but produces a high-quality, sterile product, which is favorable to consumers.”

The kill process will depend heavily on the product and the goals of the producer. HPP, bacteriophage, chlorine wash, irradiation—all have their place, says Sam Thurber, SSOE senior project manager. One solution, say HPP, will not apply to all processes. Product image for pet food is just as important as it is for human food. Regardless of the method picked, however, the kill step should be as close to packaging as possible, the goal being to eliminate any chance of re-contaminating already treated product.

Plant considerations

You can do a lot to make the equipment cleanable and sterile, run thermal or non-thermal kill steps in the process and maintain package seals, but there’s one important issue we haven’t discussed, and it’s the plant. Control of the environment is critical to maintain a safe “raw” product. Proper air filtration and pressurization, as well as consistent refrigeration temperatures are all contributing factors, says Dennis Group’s Schroeder.

Facility design and organization all starts with establishing material segregation, personnel segregation and hygienic zone definition, says CRB’s Matis. Raw and cooked side segregation is now the expectation, and process and support functions are organized around this primary demarcation. The kill step, whatever the technology becomes, is the separation point between prekill and post-kill. Zones immediately post-kill receive special attention to ensure the product remains uncontaminated in the highest zone of control, prior to initial packaging. Separate support functions and flows for waste handling, off-spec material, container washing, COP operations, etc. are key aspects to ensure minimized cross contamination. Particular attention is paid to personnel movement, maintenance accessibility and waste streams.

Festo’s Bain thinks back to a panel discussion at the FPSA conference he recently attended.

“There was a really interesting perspective from Brian Perry from TreeHouse Foods. The panel was asked if they had a huge budget to improve food safety, what would they do. He said he would rezone every old plant. He would rearrange the plants so that raw food came in one side and packaged food came out the other. ‘I would have a breakroom on one side and a breakroom on the other side, and those people would never even see each other.’ I loved this perspective, but I think it also shows a different level of mentality that the food industry should be trying to achieve.”

Wherever the kill step is finally located, it needs to be validated through the lens of a quality procedure and testing, says Dustin Gill, Burns & McDonnell project manager. “Afterward, when you have identified and validated the process, you can design and build the segregation around that kill step.”

The pet food plant of the future

As time moves on, the pet food plant of the future will become more highly automated, keeping personnel out of cold, wet and dangerous spaces, usually caused by frequent cleaning and washdowns. Until then, CRB’s Matis suggests that giving personnel the ability to transition in and out of these spaces easily, while maintaining hygienic control, will greatly enhance productivity and the work environment. 

For more on the pet food plant of the future, read "Tomorrow’s pet food plant: What it takes to stay competitive."

For more information:


Bühler Group,

Burns & McDonnell,



Dennis Group,


Festo Corporation,



SSOE Group,