Debunking Myths to Ensure Pets' Health and Longevity
In recent years, more and more pet owners have opted for homemade fresh food, hoping to provide their cats and dogs with a more natural and healthy diet. However, certain misconceptions may lead owners to underestimate the importance of scientifically designed nutrition, such as beliefs like “wild cats and dogs eat randomly and survive, so nutrition standards aren’t important,” “humans eat haphazardly, so why can’t cats and dogs?” or “a variety of ingredients ensures balance.” These ideas overlook the fundamental physiological differences between cats, dogs, and humans. Compared to humans, cats and dogs have a smaller “margin of error” in their diets. If homemade food does not adhere to scientific nutrition standards, it may lead to malnutrition or even harm their health.
This article combines three studies—Analysis of recipes of home-prepared diets for dogs and cats published in Portuguese (Pedrinelli et al., 2017), Evaluation of recipes for home-prepared diets for dogs and cats with chronic kidney disease (Larsen et al., 2012), and Evaluation of recipes for home-prepared maintenance diets for dogs (Stockman et al., 2013)—to debunk three major myths, helping pet owners understand the risks of haphazard recipes and ensure their pets eat healthily.
1. Wild vs. Domestic Cats and Dogs: Vastly Different Nutritional Needs
Some pet owners believe that wild cats and dogs survive by hunting and do not require carefully designed diets, so domestic pets can be fed similarly. However, the goals of wild and domestic environments are entirely different. Wild cats and dogs (e.g., feral cats or African wild dogs) have lifespans of only 3–7 years, often dying early due to malnutrition, disease, or harsh environments, with diets focused on short-term survival. In contrast, domestic cats and dogs, supported by balanced diets and medical care, can live 12–18 years, aiming for health and longevity. In the wild, natural selection masks dietary deficiencies; domestic pets rely on owners to provide consistent nutrition, or they risk issues like anemia or skeletal problems.
Wild cats and dogs consume prey (meat, organs, bones), obtaining nutrients like calcium and vitamin A. Domestic pets’ ingredients depend on their owners, and without scientific calculations, achieving balance is difficult. Pedrinelli et al. (2017) analyzed 106 homemade pet recipes and found that 75.6% of dog recipes lacked zinc (affecting skin and immunity) and 80.7% of cat recipes lacked vitamin B1 (potentially damaging nerves). These deficiencies show that mimicking wild diets haphazardly fails to meet AAFCO or FEDIAF standards. Owners pursuing natural fresh food should carefully calculate nutrition to avoid the misconception that “wild equals healthy.”
2. Human Dietary Patterns Do Not Apply to Cats and Dogs
Some question: if humans can stay healthy without precisely calculated diets, why can’t cats and dogs? The answer lies in the metabolic differences between humans and pets. Humans are omnivores with diverse nutrient sources, and short-term deficiencies can be compensated through adjustments. Cats and dogs, however, rely heavily on specific nutrients. Here are two key differences:
Vitamin D: Humans can synthesize vitamin D through sunlight or obtain it from food, compensating for dietary deficiencies. Cats and dogs cannot effectively synthesize it via sunlight and must rely entirely on food. Pedrinelli et al. (2017) found that 74.4% of homemade dog recipes and 50% of cat recipes lacked vitamin D, potentially harming bone and immune health in the long term.
Iron: Humans can obtain iron from beef or spinach, and though plant-based iron has lower absorption, it can suffice. Cats and dogs absorb plant-based iron poorly and rely on animal-based sources. Pedrinelli et al. (2017) found that 68.3% of dog recipes and 100% of cat recipes lacked iron, significantly increasing anemia risk without animal-based ingredients.
3. Ingredient Variety Does Not Equal Nutritional Balance
Many owners believe that regularly rotating ingredients (e.g., meats, organs, and vegetables) meets nutritional needs. However, studies show that variety alone cannot ensure balance. Pedrinelli et al. (2017) noted that 23.2% of dog recipes lacked vitamin A (affecting vision), 85.4% lacked copper (affecting iron metabolism), and 56.1% lacked selenium (weakening antioxidant capacity). In cat recipes, 69.2% lacked choline (affecting liver function) and 84.6% lacked vitamin E (affecting antioxidant capacity).
Ingredients vary significantly in nutrients—beef is rich in iron but low in vitamin D, while vegetables contain potassium but lack zinc. Stockman et al. (2013) analyzed 200 dog recipes, finding over 90% failed to meet NRC (2006) standards, showing that haphazard combinations cannot meet needs. Variety alone cannot replace scientific formulations.
4. Long-Term Health Risks of Haphazard Recipes
Haphazard homemade food can have serious consequences, especially for pets with illnesses. Larsen et al. (2012) found that in recipes for cats and dogs with chronic kidney disease, 17.9% of dog recipes lacked iron, 51.3% lacked copper, 28.6% of cat recipes lacked iron, and 10.7% lacked copper, potentially exacerbating anemia or worsening conditions with long-term use.
More dangerously, Stockman et al. (2013) found that 6.5% of dog recipes contained toxic ingredients (e.g., onions), which can damage red blood cells and cause anemia. Additionally, cats and dogs have sensitive digestive systems, and frequent ingredient changes may cause diarrhea, reducing nutrient absorption efficiency.
5. Potential Links Between Disease and Nutritional Imbalance
Many pet owners are lax about diets when their pets are healthy but start calculating nutrients carefully after diagnoses like chronic kidney disease or skin issues, such as controlling phosphorus intake or supplementing omega-3. This raises a question: are pet diseases linked to long-term nutritional imbalances? While not every disease is directly caused by diet, studies suggest that long-term deficiencies in key nutrients may increase health risks. Prioritizing scientific formulations early can reduce disease risks and build a stronger health foundation for pets.
BARF Diet: Where Nature Meets Science
Some pet owners are influenced by Dr. Ian Billinghurst’s BARF (Biologically Appropriate Raw Food) philosophy, believing that mimicking wild animal diets meets pet needs. In his book Give Your Dog a Bone, Billinghurst advocates feeding dogs and cats raw meat, organs, bones, and small amounts of vegetables to mimic evolutionary diets, without complex nutritional calculations. However, his commercial BARF products contrast this philosophy, being scientifically designed to meet AAFCO standards for balance and completeness. This shows that even “natural” diets require scientific calculations as a foundation.
Conclusion
The short-lived dietary patterns of wild cats and dogs and the flexibility of human diets cannot be applied to domestic pets. Wild environments mask nutritional deficiencies, while domestic pets need consistent diets for health; humans can compensate with diverse foods, but pets rely entirely on their owners. Ingredient variety does not ensure nutritional balance, and haphazard recipes may lead to bone diseases, nerve damage, or toxicity risks.
Pet owners pursuing natural fresh food should refer to AAFCO and FEDIAF standards and design diets scientifically, avoiding baseless experiments. Only then can they ensure their pets eat healthily, live long, and stay happy!
