Feeding Miss Lilly: Ch 4, last part

Today I'm sharing more than the last page of Chapter 4 because I want to include the whole discussion of the gut microbes and how they need time to adapt to any substantial diet change.

As a reminder, the title of Chapter 4 is 'Carnivores eat their prey raw.' Here is the final main section of the chapter.

Why do some dogs have trouble with raw food?

Some dogs don’t seem to do well on raw food, at least not at first, especially if the transition from their conventional kibble or canned-food diet is abrupt. In my experience, there are two main reasons for this trouble.

1. The gut microbes need time to adapt.

The bacteria and other microbes that inhabit the dog’s digestive tract and assist with digestion are quite simple organisms. However, the population of microbes is very complex. In any one body, there are several hundred different species of gut bacteria, probably more; and the specific profile of the population — the individual’s unique gut microbiota — reflects the life history and everyday diet of that individual.

For example, horses have between 1,500 and 3,000 different species of gut microbes. (Some studies suggest that the true number may be over 10,000 per horse.) Fiber-fermenting species predominate in horses fed a forage-based diet (pasture and/or hay). But on a high-grain diet, the carbohydrate-fermenters may outnumber the fiber-fermenters.

Dogs on meat-based diets have a predominance of microbial species adapted to breaking down animal proteins and fats. But dogs on typical dog-food diets that are heavy on grains or other starches tend to have a population of gut microbes that is intermediate between that of a herbivore and a carnivore.

That’s not a harmful thing in itself. In fact, it’s a good example of how living systems adapt. The trouble arises when we abruptly change the dog’s diet to something that is unfamiliar to its gut microbes; digestive upsets often ensue.

In my experience, that’s the most common reason people stop trying to transition their dogs onto a fresh-food diet, whether raw or cooked. The assumption is that the dog doesn’t tolerate this “radical” diet, when in fact it’s the gut microbes that are struggling to adapt.

If the symptoms are not too serious and you can both ride them out, then the gut microbes typically adapt to the new diet fairly quickly, usually in 3–5 days. But a safer and gentler approach is to make the transition more gradually.

Particularly when making such a fundamental change in the composition of the diet as the switch from the typical high-starch kibble or canned food to a low-starch, meat-based, fresh-food diet (whether commercial or home-made, cooked or raw), go slowly. Take 7–10 days to complete the switch.

Start by adding just a few mouthfuls of the new food to the current diet. Gradually add more and more of the new diet, and feed less and less of the old diet, until you’re feeding only the new diet. Depending on the dog, this transition can be completed in as few as 5 days; and occasionally it needs to be done much more slowly (over a period of 2–3 weeks).

Sometimes I recommend a probiotic product to facilitate this transition, but as time has gone on and my understanding has grown, I recommend probiotics less and less for this purpose. Except when the gut microbes have been decimated by antibiotic therapy, fresh and species-appropriate food is generally the best “pro-biotic” (i.e., promoting healthy gut biology).

probiotics

For the most part, probiotic products sold for dogs and cats are based on research done in humans and lab animals (rats and mice), although the manufacturers are not averse to using studies in farm animals (cattle, pigs, and poultry) when it suits their purpose. One thing these studies generally have in common is a diet that is high in grains or other rapidly-fermentable carbohydrates.

Equally problematic, most of these products contain only one or two bacterial species or strains, when the healthy gut is inhabited by several hundred (or more) different microbial species. These products do not reflect the normal gut microbiota of healthy dogs and cats on fresh, species-appropriate diets.

There is a small but vocal contingent of holistic vets who advise feeding the feces (poop) of healthy dogs to replace or “restore” the gut microbiome in dogs with chronic digestive disorders. In fact, proponents of this approach claim benefit for pretty much every disease you can imagine, including cancer. It is the panacea (cure-all) we’ve all been looking for…

Granted, gut health underpins general health and vitality. However, this concept is not new. Transfaunation (transfer of ‘microfauna’, or microbes, from one body to another) has been used for decades in horses and other livestock species for the treatment of digestive disorders that have not responded to less intrusive approaches. We know from long experience in these other animal species that it is a rather crude instrument and it is not always effective. It is by no means a cure-all.

Some fascinating studies in dairy cows may explain why. The rumen is the main forestomach (pre-gastric chamber) in ruminants; it’s where the majority of their gut microbes are housed and where microbial fermentation has the biggest impact on ruminant nutrition, health, growth, production (milk, meat, wool), and fertility.

When the contents of the rumen are almost completely exchanged between two cows, the individual’s unique microbiota returns toward its original profile within weeks. In as little as 2 weeks, the post-exchange profile more closely resembles the cow’s original microbiota than that of the donor.[1]

[1] ’Host specificity of the ruminal bacterial community in the dairy cow following near-total exchange of ruminal contents.’ [doi: 10.3168/jds.2010-3500] This is just one such study.

In essence, these studies show that, not only is the gut microbiota unique to each individual, but the body does its best to restore its own microbiota, even in the face of overwhelming challenge (e.g., the replacement of one’s microbiome with someone else’s).

Another problematic element to transfaunation with the feces of healthy dogs is that the most vocal proponents of this approach are also vocal advocates of vegetarian or vegan diets for dogs. As I noted earlier, the gut microbiota is a direct reflection of the individual’s diet. The microbiota of a dog on a vegetarian or vegan diet will be that of a herbivore, or at best an omnivore, rather than that of a carnivore. So, transfaunation with feces from a dog on a vegetarian/vegan diet will be of limited use to a dog on a meat-based diet.

It is also worth noting that the body considers feces as waste that is not worth keeping and trying to recycle, repurpose, or otherwise reuse. In fact, by the time the remains of a meal have reached the rectum, the body has already reused whatever it can. It has recycled some components through the liver and kidneys and it has reabsorbed and reused water and electrolytes it secreted in its digestive juices.

In all sorts of ways, the body practices economy with its on-board resources, so when it considers the feces not just waste but potentially harmful waste, I think we should respect that.

Rabbits recycle their own waste by eating some of their own feces (a practice called coprophagy). However, rabbits are strict herbivores, and one could argue that coprophagy in rabbits is similar to rumination (cud-chewing) in ruminants. But in dogs and in most other species (including humans), the body considers the feces potentially harmful waste, in need of elimination.

Transfaunation or ‘fecal microbial transplant’ is used in humans for the treatment of intractable digestive disorders, such as antibiotic-associated dysbiosis.[1] (Post-antibiotic diarrhea caused by Clostridium difficile, or “C. diff,” is a common situation in which this procedure is used in people.) However, it is considered a medical intervention, not a nutritional strategy.

[1] Dysbiosis is a medical term for disturbance of the microbiota that is serious or persistent enough to cause signs of illness. While we’re at it, fecal microbial transplant in humans has also been called trans-poo-tion, although I think it should either be transpootation or transpoosition. ??

Dogs sometimes eat the feces of other animals, so one could argue that it is a species-appropriate behavior which we are co-opting as a medical intervention. I never minded when Miss Lilly ate horse manure or the manure of wild herbivores such as rabbits and deer. That was a good way of getting a supply of the gut microbes which can make the best use of the plant portion of her diet. But the few times I saw her eating dog poop, there was something wrong with her health — and the first place I looked for clues was her diet.

I continue to follow the research on this topic, and I look forward to learning more about this fascinating and still largely unexplored and “foreign land” of the gut microbiome and the host-microbe relationship. But thus far I remain convinced that the best “pro-biotic” (pro-bios, and in this context pro-micro-bios) is food: species-appropriate food, fresh, varied, and prepared with love and care.

The best way I know of to ensure a diverse and resilient population of gut microbes is to feed a richly varied diet of species-appropriate foods. There are two essential elements in that approach, and I’ve discussed both at length: species-appropriate foods (Chapters 1 and 2), and variety (Chapter 3).

This is a proactive health strategy because a diverse gut microbiota is more robust and resilient than a more uniform (less ‘rich’) microbiota, such as one that is adapted to a diet with very little variety (e.g., the typical dog-food diet). The typical dog-food diet is not as species-appropriate as the picture on the bag or can would have us believe. Nor is it varied beyond the particular flavor (animal source) and the cost-driven substitutions the manufacturers disguise with nebulous industry terms in the list of ingredients.

By cultivating a diverse gut microbiota, episodes of digestive disorder are both less likely and less problematic (less severe and of shorter duration), with less potential for long-term disorder and associated health effects.

Generally, all it takes is a species-appropriate diet of fresh, high-quality food and a little patience and prudence through the transition.

2. The digestive juices may also need time to adapt.

To some extent, the dog’s digestive functions, including the production of stomach acid, bile,[1] and the various digestive enzymes, also adapt to the everyday diet. A feature of biological systems is adaptation, and a large part of the drive for adaptation is the need for economy: limited waste; optimal use of resources.

[1] Bile is a fluid that is made by the liver and stored in the gall bladder until it is released into the upper part of the small intestine after a meal. Its main role in digestion is to emulsify fats (similar to how dishwashing liquid “cuts grease”), thus aiding the digestion and absorption of dietary fat.

Dogs who are abruptly switched from a diet that is high in starch, as are almost all kibbles and many canned dog-foods, can initially have trouble digesting diets that are much higher in animal proteins and fats. Fibrous plant material (some veggies) can also be hard for these dogs to process.

It’s not just the gut microbes that struggle with this abrupt change. The dog’s digestive system may also need time to adapt by adjusting the production of some of its digestive secretions, especially its digestive enzymes.

A well-chosen digestive enzyme supplement can help some dogs through this transition. For dogs switching to a meat & veg diet, I prefer those that are a mix of animal- and plant-source enzymes. ’Animal-source’ means the pancreas, so the label will say dried pancreas or pancreatic enzymes; most are sourced from cattle or pigs. ’Plant-source’ enzymes are mostly from pineapple, papaya (paw paw), and other enzyme-rich fruits.

However, just like probiotics, digestive enzymes should not be fed long-term.[2] The point of using digestive enzymes is simply to help the dog make the transition to the new diet a little more smoothly. Using a crutch indefinitely does not help a body regain the ability to walk on its own.

[2] An exception is exocrine pancreatic insufficiency (EPI) — inability of the pancreas to produce enough digestive enzymes — which is very uncommon in most breeds.

One of my guiding principles is to intervene only when necessary, with only what’s necessary, and for only as long as necessary. In my experience, probiotics and digestive enzymes are overused, and they are too often relied upon in place of simple and gradual dietary changes that would allow the dog to be healthy without them.?

The only times I've encountered serious problems with raw feeding in dogs and cats are when the animal was very unhealthy and seriously lacking in vitality. In these patients, we start slowly, make changes gradually, and emphasize lightly-cooked fresh foods until the system is stronger. Whether or not the dog or cat can ever tolerate raw food is not as important as getting the animal onto a species-appropriate diet of fresh, wholesome foods.

***

Nearly there! Only one more chapter to go, and it addresses the question: how much of this food should I feed my dog?

? 2022, Christine M. King. All rights reserved.

Feeding Miss Lilly: on feeding dogs a great, nature-inspired diet (revised edition) is available as print and e-book at:

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