In mid-August I was part of a group of journalists and bloggers invited to visit the Hills Pet Food facilities in Topeka and Emporia, Kansas. Unless some of the other members of the group have access to a wondrously effective Fountain of Youth, I was most likely the oldest person in the group as well as one of the two veterinarians in it. This plus my background in animal behavior and the bond comprise the lens through which I viewed and continue to view the experience.
Get any group of ardent dog- and cat-lovers together and the subject of what constitutes the best canine or feline diet almost inevitably will come up. And more often than not, those involved in these discussions will possess strong to the point of passionate views about what this is. One adjective that repeatedly comes up in such discussions is “processed,” usually said in a tone of voice that implies a state beneath contempt. Certainly not a word that would describe food worthy to pass between the lips of a beloved companion dog or cat. Such discussions often also are liberally sprinkled with words like “natural,” “fresh,” and “holistic.”
This got me thinking about canine and feline nutrition in ethological and physiological terms. That is, what is the goal of the natural canine and feline diet? We know that dogs are omnivores who consume a wide variety of animal and plant matter, fresh or long dead. And we know that cats are carnivores, with rodents being the food of choice when cats are permitted to exercise their well-developed nocturnal and limited-light hunting skills. These foods comprise the free-roaming canine and feline natural diet and probably did for thousands of years before they aligned themselves with us. These also are the diets that their guts evolved to digest and extract life-sustaining nutrients from over the course of the animals’ lives.
Put another way these are the diets that enabled sufficient numbers of animals to survive long enough to reproduce and raise off-spring who did likewise for enough generations to ensure the survival of the species.
Now here’s the question: What would you call the contents of the vegetation stuffed gastro-intestinal tract of the herbivore that most often serves as the prey of a carnivore or omnivore? Natural or processed? Now before you tell me that no self-respecting dog or cat would eat the entrails of another animal, I beg to differ. While a particular dog or cat may live a sufficiently sheltered life that the opportunity to hunt or eat a dead animal found in a yard, park or on a walk never arises, many others have had this opportunity and few hesitate to take it when it arises.
On such occasions dogs and cats won’t eat just the large muscle masses and bones. On the contrary, the digestive tract and adjacent organs are often the first to go. In one study of wolves in the wild, the higher ranking animals had dibs on these body parts and would leave those large hide- and fur-covered muscle masses for subordinates to gnaw their way through. Decades of living with and observing hunting cats leads me to conclude that muscle meat isn’t the primary target of hunting cats either. I’m much more likely to find rodent heads, fur-covered muscular hind quarters or gutted carcasses in my house or yard than digestive tracts and internal organs.
However there’s one exception. All of the cats I’ve had since kittenhood, and most persistently the females, went through a period during which they tried to teach the resident humans and any dogs how to hunt. The usual sequence involved first leaving or even presenting the usually confused pupil with a neat pile consisting of the aforementioned digestive tract and adjacent organs. It’s understandable that humans who find this personally disgusting would decide that the cats do this because they also find these body parts disgusting and don’t want to eat them, either. But I find it difficult to accept that a queen (feline mom) who wants to ensure the survival of her surrogate offspring would offer them something that was nutritionally substandard, any more than she would offer that to her own.
But if the best diet for feline offspring is a nice healthy mouse, why not just bring us or the new dog or puppy one of them? And in fact that’s what queens ultimately do bring their own young. But not until the kittens are older, and then only after employing a carefully choreographed sequence of controlled exposure that spans the spectrum from select mouse parts to a live whole mouse the young must hunt and kill themselves. This isn’t as strange as it may seem at first. We humans do the same thing as we wean babies to highly digestible foods to which we add those that are less so as the child’s digestive capacity develops over time.
Another form of natural processing occurs when wolves are hunting food for themselves as well as pups and their care-givers who may be miles away. The wolves don’t haul the hind leg of an elk or moose back over what may be miles of rough terrain to the den. Instead, they eat as much as they can and then regurgitate some of it for the pups and caregiver to eat upon their return. Once again at first glance through the civilized human-dining lens, this is gross beyond words, behavior unfit of a caring adult. But from a nutritional stand point, the hunters are offering the young carrying their genetic legacy and their care-givers food that’s been pre-digested and warmed. And that makes digestion a much more energy-efficient activity for the recipients. This leaves the young with more energy to devote to growth, lactating females with more energy to devote to the highly energy-intense process of making milk and ensuring the welfare of the young along with any babysitters.
So in the case of regurgitation for the young and those who energy stores may be compromised by nursing or care of the young, we can say that the offered food has been processed twice before it’s consumed. First any corn, rice, wheat, grass, and/or whatever other vegetation the herbivore has eaten has been ground by that animal’s teeth, physically mixed by the contractions of the smooth muscle lining the digestive tract and and further broken down by normal digestive enzymes and micro-organisms in a +100?F environment along the way. Then the predator further processes this by consuming the herbivore and pre-digesting it prior to regurgitating a meal for the young. If we go back even further in puppy and kitten nutrition, we get that mother of all naturally processed foods: breast milk.
Adding yet another wrinkle, predator-prey pairs co-evolved in the same physical environment for the obvious reasons. It makes no sense to evolve a predatory or anti-predatory strategy for someone you’re unlikely to encounter. Co-evolution also addresses the problem of differing nutrients available in different environments. For example, those prey species living in environments deficient in certain trace minerals who possessed physiological and behavioral traits that enabled them to best locate and digest vegetation containing those minerals would have a survival advantage. And so would the predators who preyed on them instead of more nutritionally deficient prey. On the other hand, move that prey or predator to an environment where those same elements occurred in abundance and now both would be at a disadvantage.
Such is the magnitude of the problems faced by those seeking to create an ideal diet for any population of animals or even a single one that comes in a form we humans find acceptable! And we haven’t even touched on all the behavioral and bond ingredients that comprise part of the well-balanced diets wild adult canids and felines feed their young and the role these “non-nutritional” components play in the young’s survival.
For sure, processed vegetation is a natural part of canine and feline diets, and natural canine and feline diets are marvels of biochemistry about which even the most knowledgeable nutritional scientist will admit we still have much to learn. The feeding behaviors and digestive physiology of herbivores, omnivores, and carnivores is a good place to start. Logically, the goal when feeding our dogs and cats today should at least uphold this standard as well as enhance it if necessary to ensure the survival of those individual animals who otherwise might not make it. Alas, that’s not nearly as simple as it sounds.
If you have any comments regarding subject matter, favorite links, or anything you’d like to see discussed on or added to this site, please let me know at mm@mmilani.com.
In mid-August I was part of a group of journalists and bloggers invited to visit the Hills Pet Food facilities in Topeka and Emporia, Kansas. Unless some of the other members of the group have access to a wondrously effective Fountain of Youth, I was most likely the oldest person in the group as well as one of the two veterinarians in it. This plus my background in animal behavior and the bond comprise the lens through which I viewed and continue to view the experience.
Get any group of ardent dog- and cat-lovers together and the subject of what constitutes the best canine or feline diet almost inevitably will come up. And more often than not, those involved in these discussions will possess strong to the point of passionate views about what this is. One adjective that repeatedly comes up in such discussions is “processed,” usually said in a tone of voice that implies a state beneath contempt. Certainly not a word that would describe food worthy to pass between the lips of a beloved companion dog or cat. Such discussions often also are liberally sprinkled with words like “natural,” “fresh,” and “holistic.”
This got me thinking about canine and feline nutrition in ethological and physiological terms. That is, what is the goal of the natural canine and feline diet? We know that dogs are omnivores who consume a wide variety of animal and plant matter, fresh or long dead. And we know that cats are carnivores, with rodents being the food of choice when cats are permitted to exercise their well-developed nocturnal and limited-light hunting skills. These foods comprise the free-roaming canine and feline natural diet and probably did for thousands of years before they aligned themselves with us. These also are the diets that their guts evolved to digest and extract life-sustaining nutrients from over the course of the animals’ lives.
Put another way these are the diets that enabled sufficient numbers of animals to survive long enough to reproduce and raise off-spring who did likewise for enough generations to ensure the survival of the species.
Now here’s the question: What would you call the contents of the vegetation stuffed gastro-intestinal tract of the herbivore that most often serves as the prey of a carnivore or omnivore? Natural or processed? Now before you tell me that no self-respecting dog or cat would eat the entrails of another animal, I beg to differ. While a particular dog or cat may live a sufficiently sheltered life that the opportunity to hunt or eat a dead animal found in a yard, park or on a walk never arises, many others have had this opportunity and few hesitate to take it when it arises.
On such occasions dogs and cats won’t eat just the large muscle masses and bones. On the contrary, the digestive tract and adjacent organs are often the first to go. In one study of wolves in the wild, the higher ranking animals had dibs on these body parts and would leave those large hide- and fur-covered muscle masses for subordinates to gnaw their way through. Decades of living with and observing hunting cats leads me to conclude that muscle meat isn’t the primary target of hunting cats either. I’m much more likely to find rodent heads, fur-covered muscular hind quarters or gutted carcasses in my house or yard than digestive tracts and internal organs.
However there’s one exception. All of the cats I’ve had since kittenhood, and most persistently the females, went through a period during which they tried to teach the resident humans and any dogs how to hunt. The usual sequence involved first leaving or even presenting the usually confused pupil with a neat pile consisting of the aforementioned digestive tract and adjacent organs. It’s understandable that humans who find this personally disgusting would decide that the cats do this because they also find these body parts disgusting and don’t want to eat them, either. But I find it difficult to accept that a queen (feline mom) who wants to ensure the survival of her surrogate offspring would offer them something that was nutritionally substandard, any more than she would offer that to her own.
But if the best diet for feline offspring is a nice healthy mouse, why not just bring us or the new dog or puppy one of them? And in fact that’s what queens ultimately do bring their own young. But not until the kittens are older, and then only after employing a carefully choreographed sequence of controlled exposure that spans the spectrum from select mouse parts to a live whole mouse the young must hunt and kill themselves. This isn’t as strange as it may seem at first. We humans do the same thing as we wean babies to highly digestible foods to which we add those that are less so as the child’s digestive capacity develops over time.
Another form of natural processing occurs when wolves are hunting food for themselves as well as pups and their care-givers who may be miles away. The wolves don’t haul the hind leg of an elk or moose back over what may be miles of rough terrain to the den. Instead, they eat as much as they can and then regurgitate some of it for the pups and caregiver to eat upon their return. Once again at first glance through the civilized human-dining lens, this is gross beyond words, behavior unfit of a caring adult. But from a nutritional stand point, the hunters are offering the young carrying their genetic legacy and their care-givers food that’s been pre-digested and warmed. And that makes digestion a much more energy-efficient activity for the recipients. This leaves the young with more energy to devote to growth, lactating females with more energy to devote to the highly energy-intense process of making milk and ensuring the welfare of the young along with any babysitters.
So in the case of regurgitation for the young and those who energy stores may be compromised by nursing or care of the young, we can say that the offered food has been processed twice before it’s consumed. First any corn, rice, wheat, grass, and/or whatever other vegetation the herbivore has eaten has been ground by that animal’s teeth, physically mixed by the contractions of the smooth muscle lining the digestive tract and and further broken down by normal digestive enzymes and micro-organisms in a +100?F environment along the way. Then the predator further processes this by consuming the herbivore and pre-digesting it prior to regurgitating a meal for the young. If we go back even further in puppy and kitten nutrition, we get that mother of all naturally processed foods: breast milk.
Adding yet another wrinkle, predator-prey pairs co-evolved in the same physical environment for the obvious reasons. It makes no sense to evolve a predatory or anti-predatory strategy for someone you’re unlikely to encounter. Co-evolution also addresses the problem of differing nutrients available in different environments. For example, those prey species living in environments deficient in certain trace minerals who possessed physiological and behavioral traits that enabled them to best locate and digest vegetation containing those minerals would have a survival advantage. And so would the predators who preyed on them instead of more nutritionally deficient prey. On the other hand, move that prey or predator to an environment where those same elements occurred in abundance and now both would be at a disadvantage.
Such is the magnitude of the problems faced by those seeking to create an ideal diet for any population of animals or even a single one that comes in a form we humans find acceptable! And we haven’t even touched on all the behavioral and bond ingredients that comprise part of the well-balanced diets wild adult canids and felines feed their young and the role these “non-nutritional” components play in the young’s survival.
For sure, processed vegetation is a natural part of canine and feline diets, and natural canine and feline diets are marvels of biochemistry about which even the most knowledgeable nutritional scientist will admit we still have much to learn. The feeding behaviors and digestive physiology of herbivores, omnivores, and carnivores is a good place to start. Logically, the goal when feeding our dogs and cats today should at least uphold this standard as well as enhance it if necessary to ensure the survival of those individual animals who otherwise might not make it. Alas, that’s not nearly as simple as it sounds.
If you have any comments regarding subject matter, favorite links, or anything you’d like to see discussed on or added to this site, please let me know at mm@mmilani.com.