If you have a dog or cat, then your household is among the 56% of U.S. households that are home to one or more of these 140 million four-legged family members (U.S. Pet Ownership & Demographics Source book, 2012). “Pet parents” expect the food they purchase for their dogs and cats to deliver benefits in terms of improved health, increased energy, enhanced performance, and better resistance to diseases such as obesity, hypertension, diabetes, and heart disease. So you might say that there has been a transition from basic nutrition to the “humanization” of pet foods in terms of consumers’ expectations.

It is important for consumers to understand that health issues that affect humans do not necessarily translate to health issues for companion animals. It is also critical to recognize that foods and ingredients as well as the amounts considered safe for human consumption may not be safe or appropriate for consumption by dogs and cats.

There is evidence that obesity, a significant health concern among humans, is also a health issue among dogs (German et al.,2011). For humans, there are many health risk factors associated with obesity, which are often packaged as metabolic syndrome and may include insulin resistance, hypertension, and dyslipidemia, which contribute to diabetes and cardiovascular disease.

Do dogs and cats present the same risk factors? These animals do not present the clinical consequences observed among humans (Verkest, 2014). Cardiovascular disease risk factors are seldom observed among dogs. Thus the classic saturated fat and cholesterol “avoidance” recommendations prescribed for humans are not applicable to dogs and cats. However, diabetes is considered common among dogs (0.5-2%) and cats (0.25-2%), yet it is not well described among them (Rand et al., 2004; Fall et al., 2007).

Gluten-free foods are important for consumers who present gluten-intolerance and celiac disease. Despite the marketing of gluten-free pet food products, this is not a health issue among most companion animals. There is limited information on gluten sensitivity among some breeds such as Irish Setters (Garden et al., 1998). However, gluten-sensitivity issues typically improve or resolve spontaneously by 12 months of age despite exposure to dietary gluten. This is not to minimize the issues of chronic inflammatory conditions in some animals. However, these presentations differ from those observed in humans; thus the interventions differ between humans and dogs (German et al., 2003). Among cats, the prevalence of food sensitivities affects 1–11% across breeds (Guilford et al., 1998).

The incorporation of dietary polyphenols, which may function as antioxidants under some physiological conditions, has been an area of intense research for several decades (Halliwell, 2008). Many human clinical trials provide inconsistent results and even suggest increased consumption may accelerate disease (Albanes et al., 1996; Moyer, 2013), while diet and health experts encourage the consumption of fruits and vegetables for better health. A recent publication using a mouse model indicates antioxidants may exacerbate disease instead of improving health (Sayin et al., 2014). When it comes to polyphenols and canine health, there are very few direct studies. Reviews from human studies have been transferred to potential health outcomes among dogs. Two recent studies among dogs supplemented with an array of polyphenols and vitamins suggest oxidative stress may be reduced (Sagols & Priymenko, 2011; Salas et al., 2009). One of the mechanisms appears to be through altered gene expression instead of the presumed mode of action through free radical scavenging. Important to these findings is that two studies among beagles show that doses of green tea extract above 200 mg/kg bw may be toxic as noted by unexpected mortality and morbidity (Kapetanovic et al., 2009). Interestingly, the data indicate the pharmacokinetics of these compounds differ among dogs depending on their fasted or fed state.

Since 1998, nearly 50 studies on dogs and the gut microbiome have been reported. The typical cocktail of organisms (109—1010 cfu/g) suggests potential benefits in reducing gut inflammation and risk of urinary tract infections (Schmitz et al., 2014; Rossi et al., 2014; Hutchins et al., 2013). Since the gut microflora of dogs and humans differ, it may be important to select “friendly” microbes isolated from dogs and strains that provide desirable physical and physiological characteristics, including the ability to survive the digestive process, adhere to gut mucosa, maintain stability in process and storage, and perhaps secrete unique bacteriocins that inhibit gut pathogens.

Feeding pets more like humans is a significant trend in the pet food industry, but it is important to remember that the nutritional requirements and health issues among companion animals are not the same as those of humans.

Roger ClemensRoger Clemens,
Dr.P.H., CFS,
Contributing Editor
Chief Scientific Officer,
Horn Company, La Mirada, Calif.
[email protected]