Recently the following question appeared on a dog feeding forum I frequent. I thought it might make for an interesting discussion.
“I have been doing some reading about “methionine restriction” and “protein restriction” as a way of increasing human longevity. Does it apply to dogs as well? I have been assuming so, and have been putting my rescues on a vegan diet, like I feed my own dog. The problem is that they end up with terrible alkaline urine and struvite crystals. The antidote is Methionine capsules to acidify urine, so I am back to square one. Help!”
Thanks, Shitzu Rescuer
Methionine is one of the amino acids in animal products, so when you restrict consumption of all animal products, it doesn’t make any sense to call this a “methionine restricted” diet, like methionine is the only bad guy in meat. There are obviously LOTS of problems with meat, especially modern meat, and identifying just one substance in it that might be either prevalent or particularly harmful (I’m frankly not even sure it is harmful at all to animals that are adapted to consume animal products) has no advantage and may keep us from seeing the big picture. In fact, there are so many other problems that can result from feeding the products of modern animal agriculture to dogs on a regular basis that I’m not even sure that the benefits that are seen when these are decreased are even attributable to simple “protein restriction”.
It should also be pointed out that what may be true for humans will not necessarily be true for dogs, or any other species, for that matter. Dogs and humans have very different dietary requirements.
All of this notwithstanding, the merit of cutting back on protein for dogs should be acknowledged and investigated, at least by dog owners wanting optimal health for their dogs. The mistake that people make is allowing their ideas about canine taxonomy classifications to confuse them. It’s not that dogs aren’t carnivores, or omnivores with a special bent for meat consumption, (whichever camp you’re in), it’s that they just don’t eat much. They thrive when nature keeps them ‘underfed’ (by conventional standards), which nature seems to have done, throughout their biological history. In pristine nature, food is not generally abundant and it is not easy to get.
When dogs are fed their primary foods (prey) infrequently, as they might get them in nature, they seem to do very well. Even feeding them non-animal foods from which they can get sufficient protein (but less than they would get eating equivalent amounts of animal foods) seems to result in overall benefits, especially when compared to the level of health dogs normally experience in civilization (not a good standard to go by). It seems clear to me that the common denominator is ‘underfeeding’ protein foods, such that consumption lines up with what a dog would have access to in the wild. Since protein is a lot more abundant in animal products, people who feed them just need to replace meat days with fruit or (selected) vegetable days, or fasting days. Vegan feeders might not need to ‘restrict protein’ at all, since the foods they’re feeding are by their nature lower in protein than a dog’s natural primary foods (prey), and don’t have the same problems that protein foods do (which is not to say they don’t have other problems, which will vary depending on the specific food).
As my dog has gotten older, I have had to continually decrease his consumption of animal products, and I’ve had to be particularly selective about the quality of meats I give him. Recently I did some intermittent fasting myself and didn’t have fruit or vegetables on hand to feed him. So I fed him frozen conventional chicken 4-5x per week for about a month. The result was symptoms like urinating at night, noticeable weight gain, coughing, stiffness in the morning and difficulty walking on slick surfaces (tile floors). When I fasted him for 4 days and started back on rotational feeding (fruit/yams/meat), he was back to his normal self in short order. I noticed within a couple weeks he was trotting alongside me when we walked instead of being behind me 10 paces as he was before. That’s pretty good for an 18 1/2 year old dog, imo.
I don’t know anything about methionine supps clearing up alkaline urine and crystals, but if it works I wouldn’t worry about it not being consistent with the methionine restriction that is behind your vegan feeding. Rather, what I would concern myself with is removing the CAUSE of the crystals, which would mean looking at the foods you feed to determine which ones are causing it, and not feeding it/them anymore. And I would also worry that the supps would add to the dogs’ toxic burden, since processed nutrients are not utilized by the body and must just be eliminated along with all the other unusable substances that come in. They may act to suppress one symptom, but they cause others (euphemistically called ‘side effects’), as all remedies do.
Best wishes, Nora