Many pet parents today are interested in learning about optimal nutrition for their furry loved ones, and the first place they seek answers is often on the internet. Unfortunately, there are a variety of blogs and courses published online that may disseminate inaccurate or biased information. There is a lot of information out there, so how does one sort out fact from fiction?

While nutrition science isn’t perfect, it’s the best approach we have to figure out how to best feed our pets. The following review is part two of a series featuring evidence-based approaches to some common myths found online about pet food and the pet food industry.

Myth No. 11: Pet food is not safe because it does not require FDA approval before going to market.

Pet food, like human food, does not need approval by the FDA before going to market, though it is the ethical responsibility of food producers to ensure only approved ingredients are used and safety measures are met. Regulatory agencies review and test foods on the market to make sure they comply with their labels and do not contain contaminants.

However, all food is susceptible to a recall if a regulatory body determines that it poses a hazard to human or animal health. Hundreds of human food recalls occur in North America every year, compared with only a handful of pet food recalls. It is in everyone’s best interest to keep the food supply as safe as possible for ourselves and our pets.

Though mistakes can happen, nutrition and food science technologies developed over the past several decades have created a safe food supply to feed millions of humans and their pets.

Myth No. 12: Extrusion sometimes can’t get rid of all anti-nutritional factors in plant-based ingredients.

The presence of anti-nutritional factors is often raised in relation to plant-based ingredients in pet foods. For example, some people are concerned about lectins (a type of carbohydrate-binding protein) in peas.

Lectins are believed to have evolved to protect the plant by causing intestinal discomfort in animals that eat them. However, lectins must be consumed raw in large quantities to produce this discomfort, and moderate heat treatment, such as that used to make dry and canned pet foods, inactivates the anti-nutritional properties of lectins (Roy et al., 2010).

In fact, controlled amounts of anti-nutritional factors may have health-promoting properties. Data in humans suggests that when properly processed, lectins may help to prevent or treat certain diseases such as heart disease and diabetes by helping to control obesity (Roy et al., 2010). Preliminary research has shown that lectins also may have anti-cancer and immune-boosting effects (Roy et al., 2010).

Myth No. 13: Synthetic vitamins are dangerous and do not provide the same benefits as whole foods.

The word “synthetic” does not automatically mean that something is inferior. Vitamin manufacturers have developed sophisticated technologies to produce the most useful and stable forms of individual vitamins, which are well utilized and handled by the body.

Many factors are taken into consideration when designing a vitamin or mineral premix, including the nutrient quality, bioavailability, stability, and physical characteristics. Whether it is a vitamin, mineral, or other nutritional supplement, strict quality control is put in place to ensure consistency and safety.

Furthermore, since many nutrients react with other food components, adequate stabilization protects the nutrient from degradation and is critical to ensuring correct nutrient levels in the food. There is no research to support defining synthetic vitamins as dangerous when fed in appropriate levels for dogs and cats. Any nutrient can be harmful if fed in excessive levels, whether the source is from foods or supplements.

Myth No. 14: Kibble is not very digestible.

A lot of research has been performed to examine the digestibility of kibble and it is in fact highly digestible. Research has demonstrated that the protein, fat and starch digestibility in kibble is upwards of 90 percent in cats and dogs (Asaro et al., 2017; Sá et al., 2013).

Fiber, by definition, is not digested, playing a critical role in digestive health and promoting regularity. Fiber can be particularly important for small breed dogs susceptible to anal glad issues by helping create a bulkier stool.

Myth No. 15: Processed foods have a higher risk of mycotoxin contamination.

The risk of mycotoxin contamination is not related to the processing of pet food; rather, it is related to quality control practices for ingredient sourcing. Testing for mycotoxins in ingredients is a key step in producing healthy and safe food for both pets and humans.

Myth No. 16: Processed foods negatively affect the microbiome.

Many aspects of food and an animal’s overall diet composition affect the microbiome, including nutrient content, prebiotic/probiotic content, and processing methods. Although food processing will impact the microbiome, research in this area is still relatively new and it is unknown whether processing has negative effects.

While processed foods in the human food industry are often viewed unfavorably because many of them are high in fat, salt, and sugar, this is not the case for most pet foods. There are many advantages to processing food. Processing technologies have evolved significantly over the years to create safe, convenient, nutrient-dense foods, and help secure a stable supply.

Processing can increase the digestibility of some macronutrients, allowing them to be more readily absorbed (Tran et al., 2008). Cooking food is a key step in maintaining food safety by destroying harmful pathogens; undercooked meat is a well-known source of pathogens for both humans and animals. Additionally, processing allows manufacturers to incorporate fiber into kibble, which can subsequently act as a food source for the beneficial bacteria in the GI tract, thereby promoting a beneficial microbiome for the animal.

Myth No. 17: Carbohydrates in the diet cause a disruption of the microbiome, and impaired nutrient absorption.

Studies have shown that consumption of a diet high in carbohydrates can increase the evenness (the balance of bacteria type) of gut microbiota in dogs (Li et al., 2017). A lack of dietary carbohydrates results in intestinal bacteria using amino acids as their energy source, leading to an increased production of ammonia, a foul-smelling compound excreted in the urine. Additionally, we are not aware of any research that supports a negative correlation between carbohydrate content and nutrient assimilation in cats or dogs.

Carbohydrates, namely starch and dietary fiber, are important components of pet foods. Although carbohydrates are often considered “fillers,” they do play a critical role in your pet’s body. In particular, carbohydrates provide a highly digestible, readily available energy source. Foods rich in complex carbohydrates are also an important source of essential nutrients.

Fat and carbohydrate are the preferred energy sources for the body, but protein can also be broken down to provide energy. However, animals are unable to store excess amino acids. What is not utilized for tissue maintenance must be dealt with by the liver and kidneys.

When compared to carbohydrates and fats, protein as an energy source is metabolically expensive due to the structure of amino acids. The body must first break protein down into amino acids to be utilized for energy. If the amino acids are not needed by the body for another purpose, the nitrogen portion of the amino acids is converted in the liver to an end-product called urea which is excreted in urine, and the carbon portion of the amino acid is converted to fat.

Nitrogen, from urea and other sources, is an environmental contaminant. Overfeeding protein by reducing carbohydrates not only serves as an inefficient use of energy but also leads to increased nitrogen (i.e. urea) excretion and environmental ammonia levels. The more protein that is fed above requirements, the more urea is excreted. High concentrations of urea in the urine result in yellow and burnt spots in grass.

Myth No. 18: If you feed your puppy less food, they might not get enough calcium.

AAFCO minimum calcium recommendations for puppies have been established based on years of research. Switching to a food with higher calcium can be detrimental to puppies and lead to skeletal diseases, especially in large breed puppies. It is important to continuously monitor your puppy’s weight and body condition score to ensure they are not gaining excess body fat, a sign of overfeeding. Extra calories can increase the rate of growth in puppies which is associated with abnormal bone development.

Myth No. 19: Food should not be frozen as it can increase oxidation and add moisture to food.

Freezing is a centuries-old method of food preservation to prevent microorganism growth. It is one of the safest methods of preservation; without it, tremendous amounts of food would be wasted.

Cold temperature storage helps keep food fresher for longer and keeps food safe by decreasing the water activity and reducing the multiplication, resistance, and survival of potentially harmful organisms (Leistner, 1992). Appropriate packaging prevents the gain or loss of moisture. Moisture loss, or ice crystals evaporating from the surface of a product, can occur during frozen food storage which causes freezer burn and a loss in product quality. However, this is easily prevented with proper packaging.

Fat oxidation is what contributes to food going rancid. Fresh meats and fish spoil quickly at room temperature due to bacterial growth. This can be slowed using refrigeration, but the shelf life only extends by a few days.

On the other hand, freezing greatly extends the length of time a food can be stored. While fat oxidation and a decrease in omega-3 fatty acid content can occur in frozen foods that have been stored for many weeks, there are significant benefits to freezing for maintaining food safety and quality of fresh meats and fish. Freezing at lower temperatures and rapidly freezing food helps to reduce fat oxidation. Since many people and their pets do not live next to an ocean or lake where fresh fish is abundant, freezing helps increase accessibility to these types of nutritious foods.

Myth No. 20: Because tests don’t distinguish between pathogenic and non-pathogenic Salmonella, many of the raw foods that are recalled may not pose a risk for illness.

There are two species of Salmonellaand over 2500 serotypes, or strains. All 2500 serotypes can cause disease in humans; therefore, no strain can be considered non-pathogenic (WHO, 2018).

The decision to recall a food is not done lightly; a pet food company would not recall a food unless they were concerned about its safety for the public. Furthermore, the FDA guidance documents for testing for Salmonella span both Human foods, and “Direct-Human-Contact” animal foods, including pet food. Therefore, the same validation processes that apply to human food also apply to pet food.