Over the past two decades, there has been a veritable explosion of information about canine nutrition, with books such as Dr. Billinghurst’s series on raw feeding, Richard Pitcairn’s venerable Natural Health for Dogs and Cats, and a multitude of newer recipe books – some of which offer reasonably balanced recipes, others that appear to not even have bothered with the basics, and succeed by appealing more to human aesthetic sensibilities than to canine needs. Pet food companies, following consumer trends and demand, are offering a range of “premium” foods such as we have never witnessed since the start of the kibble and canned food industry; many of these formulas rely heavily on marketing/appeal to the consumer trends, promising to mimic the “ancestral diet” of the domestic canine – or simply make the consumer feel really good about the product by putting a wolf on the bag.
I am a bit of a cynic when it comes to trends in nutrition and marketing gimmicks designed to appease the public’s latest craze for – well just about anything.And lest I sound too terribly jaded; the plethora of books, social media groups, websites, and commercial products is not all a bad thing – far from it. I remember way back when I first started feeding one of Dr. Pitcairn’s recipes to my own dog – there were only two brands available to me here in Canada, Innova and Wysong. When I went to the local butcher to ask for bones and hearts and fattier ground beef for my DOGS, I was stared at like the Village Weirdo. Times have changed with regard to canine health concerns – and that’s clear cause for celebration. But along with an increase in the good stuff – consumer and veterinary awareness, better food for dogs, much more to choose from – along with this comes an awful lot of hype, sloganism and reductionism; a lot of generalizing, and, perhaps most alarmingly, a huge amount of fanaticism.
However; dog food is what I do for a living – part of what I do, as a therapeutic nutritionist and herbalist. When you do the work I do, centered on canine nutrition for all kinds of dogs, all health issues and conditions – you get to see far more deeply into the reality behind the hype and pop-nutrition approaches. Dog food trends and gimmicks bug me, I admit it. There’s good reason for that. High protein is not the best choice for all dogs; all dogs are not one identical entity who should eat as we believe wolves do; raw is not always optimal and carbohydrates as a group are not “the enemy”. Yet, daily, I have to hear this trumpeted loudly , with a marked lack of critical analysis. In this entry, I want to go into why this is worrisome and why, if nothing else, people should learn the facts of canine nutrition before jumping on any dietary bandwagon. What works for your neighbour’s aging Basset Hound may be totally wrong for your youthful Weimaraner. What works for your aging Basset hound NOW, may not in another year. If you’ve had 4, 12, 25 basset hounds in a row all doing well on (BARF, Pitcairn, premium kibble, fill in the blanks) there is no guarantee the very next one you acquire will do as well. All dogs are not the same and furthermore, they change throughout life. Many do great on commercial diets, ad hoc home made diets, some even live long happy lives on really awful food… but, none of this makes a case that any one method of feeding is optimal for all dogs. It really doesn’t. I promise you that.
In this blog I plan to go through breeds, conditions, life stages, compound problems and more, to illustrate just how personal nutrition really is. For dogs as well as for us. There are some rules, sure there are; we stop taking in Vitamin C, we get scurvy. Yes there are requirements and those need to be understood and supplied. But outside the requirement box, there’s a sea – an ocean of individuality. So the remark “I feed a raw diet” or “my kibble is grainfree” tells me only one thing; this works for YOUR DOG at THIS TIME . Both of these diets are disastrous for many other dogs. I have seen it, lived it, made it my main area of research for twenty-two years now. And one of the most oft-quoted and deeply misunderstood aspects of the trend to homogenizing canine needs, is the statement “Dogs are carnivores” – which leads directly and immediately to, ” therefore we should not feed any carbohydrate”.
There are so many problems with this nearly-universal extrapolation I hardly know where to start. It seems to come from three sources: one, the idea that dogs are strict or obligate carnivores like the cat( false); two, that there is no recognized requirement for dietary carbohydrate in the canine diet (true) and three, that all individuals will thrive on one specific type of diet (wrong, wrong, wrong).
Let’s take a look, first and foremost, at what the differences are between and obligate and a preferential carnivore.
First of all, a basic but also fairly useless definition of the term: a carnivore is an animal member of the family Carnivora. Perhaps more pointed is the Latin meaning of the word: which reduces to “flesh-eaters”. Carnivores are animals that eat other animals. They are adapted physiologically, anatomically, metabolically to deriving most or all of their nutrient requirements from flesh, fat and bone. That’s still a broad definition. A closer look reveals some striking differences between individual species within the family. I like to contrast dogs with cats to highlight why canines not only can but should be fed a reasonable amount of specific types of carbohydrate. And while it’s beyond the scope of this entry to provide a full comparative analysis of canine and feline digestion, there are some standout points that should be understood.
– while neither cats nor dogs secrete salivary amylase as true omnivores do, their dentition is significantly different. Cats have 10 premolars and only 4 molars, teeth designed for grinding and breaking down plant matter, whereas dogs have 16 premolars and 10 molars. (2023 Update: we know now that some dogs do, in fact, secrete salivary amylase)
– length of digestive tract (cats much shorter and much smaller cecum). Both have shorter GI tracts than omnivores, but the dog’s is better adapted to digesting plant matter.
– pancreatic amylase activity – about three times higher in the dog, meaning greater amounts of starch are readily digested
-Vitamin A: The cat differs from most other species (including the dog) which can satisfy at least some of their Vitamin A requirements with dietary carotenes. Cats lack the metabolic pathway necessary to convert carotenes to retinol, the active form of vitamin A, and therefore need dietary pre-formed vitamin A. This means a source of animal fats, as pre-formed vitamin is not found in plants.
– fatty acid requirements – cats require dietary arachidonic acid while dogs can metabolize adequate levels from linoleic alone
– protein requirements in the cat are significantly higher than the dog, and taurine must be supplied dietarily -unlike the dog, who can make enough endogenously to meet needs, provided adequate amino acid precursors are supplied. Dog’s RA (recommended allowance for total dietary protein is 3.28 grams per unit of BW (to the power of 0.75) while the cat needs 4.96 (to the power of 0.67).
– L-arginine sensitivity: arginine is a key amino acid in the urea cycle.. The effect of arginine deficiency in cats is particularly dramatic; they will become ill within a few hours of eating a deficient meal. Clinical signs include lethargy, hypersalivation, vocalisation and ataxia, all as a result of ammonia toxicity. Most other animals require arginine (at least for growth) but they are far less sensitive to a deficiency of this nutrient
-niacin requirement – while the dog is able to convert the amino acid L-tryptophan to niacin, the cat cannot, and thus must ingest a preformed source in order to meet requirements
The short version is while cats and dogs are indeed both carnivores, there are many nutritional differences, and dogs can survive and even thrive on vegetarian diets while cats, as obligate carnivores, cannot. You will hear “dogs are carnivores” cited as a good reason to feed not just a high fat and protein diet (which may or may not work) but an ALL fat and protein diet (which has some serious drawbacks and may even set the stage for illness to develop). Are you starting to see why I gnash my teeth everytime I hear “Grain free, no-carb” touted as the Gold Standard of diets for all dogs? If you’re not sympathizing yet, by the end of this series I think you just might.
When I was casting about in google looking for something succinct to offer, by way of comparing an obligate carnivore to a preferential, I found mostly very biased sites proclaiming the merits of a “raw, species-appropriate diet” and contrasting “dogs and cats” with omnivores and herbivores. A finer distinction as you have seen, occurs when we compare the dog with the cat. I would encourage everyone with a serious interest in this topic to look past the sites pushing one diet over all others, look past the books and Facebook groups pushing everyone to one type of diet, and learn some real nutritional science to start with. Once you are armed with an arsenal of facts, it’s much harder to get sucked in by rhetoric and half-truths represented as science. Your dog is a preferential carnivore, and he or she should have a good presence of meat, poultry, fish, eggs – protein and fat – in the diet. There is also an important place for *some* carbohydrate; how much and what type will depend on your dog; his or her unique system and responses. In my “Think like a Nutritionist” series we’ll talk about the foods we call carbs and take a look at how much and what type to use – and above all, why. WHY? if the dog doesn’t *need* – read, require, any carb in the diet – so what if his mouth, gut and metabolic tendencies suggest that he *can* eat them? Why should we feed them?
I’ve covered a fair bit about carbohydrates – pro and con – in my four-part series, in the hope of persuading readers to think about carbs as a pro/con option, and consider your dog as an individual, learn what the real values and drawbacks are of adding carbs are. I hope this article has helped a bit, in distinguishing a true carnivore like the cat, from a preferential like the dog, who is more adapted to consuming plant based foods and will not always do well on a diet consisting of only protein and fat.