Shark week, moon time, the crimson tide, a visit from Auntie Flo: whatever you call it menstruation is the roughly monthly interval during which the uterus sheds its lining. For the uterus owner, it is not generally a super fun time; cramping, bloating, headaches, and fatigue are just a few of the symptoms associated with “that time of the month.”
The symptom I want to focus on today, though, is hunger. Whether for chocolate, pizza, or any food really, an increased hunger is a commonly reported phenomenon during, or right before, menstruation. Although we know that periodic (get it?) changes in appetite can be influenced by fluctuations in hormones such as estrogen and progesterone, I became curious whether this increase in hunger also correlated with an actual increased need for energy from food. Just like our bodies produce the sensation of thirst when they require more hydration, maybe they produce the sensation of hunger during menstruation in part because of an increased caloric need.
Given the breadth of commercially available dog foods it can be tricky for dog owners to make informed decisions on how to feed their pets. Add into the mix the wealth of websites and books advocating for specialized dog diets and feeding your dog well can seem like a monumental task.
In a previous article I addressed what owners are able to know about a type of food, and what they aren’t, based on the package.
There is, however, a lot more nuance to the world of dog food than could be covered in one article. From vegan diets to how to feed nursing moms, there are a lot of questions I’ve left unanswered, so let’s try to answer a few.
How to Feed Dogs Throughout Their Lives
Dogs, much like humans, have different energy and nutritional requirements during different stages of life.
Pregnant dogs require slightly increased levels of protein, although only for the last few weeks of gestation, since 75% of fetal weight is attained in this time.
Foods for growing puppies also need to be slightly higher in protein, to accommodate their rapid growth. Larger breeds will grow over a longer period of time (~15 months) than their toy-sized counterparts (~9 months), so you can expect to be feeding them puppy chow longer.
You do not, however, want to continue feeding milk to growing dogs. Their ability to digest dairy products falls with age, as the lactase activity in their intestines decreases. Your dog may love cheese, but more than a small bit will leave him pretty unhappy.
As dogs age, their metabolic rates will naturally slow down, as will their activity levels. With this should come a reduction in their caloric intake. Specially formulated senior pet foods will generally be lower in calories while still containing all the essential nutrients, and some will also contain compounds to help dogs suffering from arthritis.
While it is a common myth that protein consumption can worsen the condition of dogs with renal disease, this is not true. Older dogs tend to be more affected by renal issues, and they actually have a slightly increased protein need to account for the age-associated losses of the body’s protein reserves.
Dogs with jobs (like these ones) will need to have their nutrition adjusted according to the energy they expend throughout the day. Sled or search-and-rescue dogs will require an increased portion of fat in their diets to supply fuel for their longer-term aerobic exercise, whereas dogs who engage in brief stints of intense exercise, like greyhounds, require more carbohydrates in their diets to fuel their anaerobic respiration.
Should dogs eat grain-free?
It’s commonly said that dogs are unable to digest carbohydrates. This is just not true. Dogs have evolved over the 14 000+ years since their domestication to have quite different digestion than their wolf ancestors.
In 2013, researchers compared the genome sequences of 12 wolves with those of 60 dogs and found that the regions selected for since the domestication of dogs fell into two categories: those which alter the nervous system (and therefore potentially behaviour) and those which alter starch digestion.
As humans switched to a predominantly agriculture-based lifestyle, they created more permanent settlements, near which food scraps and waste would be disposed of. An early adaptation allowed wild dogs to digest these starch-rich castoffs and helped them to thrive in this new ecological niche.
However, in all mammals (including humans) carbohydrates are a non-essential nutrient. The glucose required by the body can be synthesized from amino acids and fats through gluconeogenesis. So, it is possible to meet the nutritional requirements of dogs, and yourself, without eating carbohydrates, but it’s not necessary. While dogs do not have amylase in their saliva as humans do, their pancreases produce enough amylase and other enzymes to break down carbs quite well.
Many dog foods market themselves as grain-free, a statement that is often misinterpreted as carbohydrate-free. Grain-free diets are not necessarily even low in carbs, never mind carb-free. Grains are a common source of carbs, but they are not the only one. The fruits and vegetables included in your pet’s food contribute necessary vitamins and minerals, as well as carbohydrates.
The term “filler” is thrown around a lot when talking about grains in dog foods. As grains contribute protein, amino acids, fibre and vitamins, referring to them as filler (i.e. nutritionally useless) is simply wrong. Dietary fibre provided by carbohydrate-rich foods like grains and legumes helps ease bowel movements in dogs just as it does in humans. Further, grain-free diets tend to replace the metabolizable energy lost with the exclusion of grains with increased fat content.
While gluten intolerance is increasingly common in humans, food allergies in dogs are considered quite rare. Grain allergies make up only 1-2% of these already rare allergies, so the risks of your dog being intolerant of the grains in their food is quite small.
Should dogs follow the raw diet?
A growing number of pet owners are advocating for feeding their animals some variation of the BARF (Biologically Appropriate Raw Food) diet. Numbers vary, but one study found that 8% of dog owners in the U.S. and Australia currently feed raw meat and/or bones as their dog’s main meal. Many proponents of these diets will draw connections between their pet dogs and their wolf ancestors, but as discussed, 14 000 years of evolution have left domestic dogs with very different digestive systems than their wolf ancestors.
There are two main problems arising from feeding dogs bones and raw meat (whether it makes up all or only some of their diet): bacterial contamination, and nutritional deficiencies. Atleastfivedifferentstudies have found that both commercial and home-prepared raw diets are commonly contaminated with bacteria like Salmonella and E. coli. This is especially true of, but not limited to, diets containing raw chicken.
If raw foods are left sitting in dog bowls, the risks get even higher. Traditional methods of cleaning pet bowls are unlikely to completely remove bacterial contamination, and the quantity of bacteria present on food increases rapidly as it sits out.
The bacteria found on raw meats are not only a risk for dogs however. Severalstudieshaveshown that dogs fed raw diets shed bacteria in their feces. Any person who comes into contact with these feces, whether by cleaning it up or just encountering some inevitable residue on the dog itself, is at risk of bacterial infection. This is especially hazardous when dogs are in contact with the young, elderly or immunocompromised, such as therapy dogs who visit care homes or hospitals.
The problem of nutritional inadequacy is a major one when it comes to both raw and cooked home-prepared dog food. One study found that of 95 raw meals reportedly fed by German pet owners, 60% were deficient in at least one essential vitamin or mineral. A different study found that 35% of veterinarian-recommended, long-term homemade recipes for dogs were nutritionally deficient, and yet another study found that 86% of published dog diets were deficient in various minerals, and 55% were deficient in protein.
Part of the problem is that while human meals have a considerable amount of leeway in terms of substitutions, specially formulated dog diets do not. One study showed that a majority of owners do not strictly stick to recommended homemade diets. Swapping one type of protein for another, or even just buying a different leanness of ground beef can alter the entire nutritional profile of the food and cause imbalances.
If you are feeding your dog a BARF diet, there are some specific things to be careful of. Care should be taken when giving dogs bones (particularly poultry bones) to ensure that they don’t choke, and raw fish should never be given to dogs. Many fish contain thiaminase that can destroy dietary thiamine (vitamin B1) and cause a nutritional deficiency.
Can dogs be vegetarian or vegan?
Perhaps surprisingly, yes!
But having a vegan dog is more difficult than going vegan yourself.
As I explained above, dogs can digest carbohydrates and grains quite well. So, the main issue with excluding meat and/or animal products is in nutritional, not caloric, deficiencies.
Dogs who are eating vegetarian or vegan may face vitamin deficiencies, just like their human vegan counterparts. To combat this, commercial vegan dog foods will often be supplemented with vitamins that are difficult or impossible to find non-animal sources for, like vitamin B12, taurine and vitamin A.
One study analyzed 12 commercial vegetarian dog foods and 86 homemade vegetarian diets and found many of them to be nutritionally bereft. Home prepared diets, regardless of their vegan status tend to be nutritionally lacking, so you can imagine that cutting out an entire food group doesn’t fix this problem.
If you really do want to transition your dog to a vegetarian or vegan diet, I would highly, highly, recommend talking to veterinarians and canine nutritionists, to ensure that your pet is getting all that they need to stay healthy.
In the end, every dog is a unique creature with unique needs, likes, dislikes and health situations. The best option for every pet owner is to talk to their veterinarian about what is best for their particular dog.
That, and remember to keep the chocolate, onions, garlic and grapes away from man’s best friend.
Forgive me if I sound like I’m confessing to being an alcoholic or naturopath, but with all the misinformation, pseudoscience and nonsense that plague the vegetarian and vegan worlds, being a vegetarian scientist can sometimes feel like being a walking oxymoron.
In my experience there are 3 main reasons one becomes a vegetarian (not including a distaste or allergy for meat, in which case their vegetarianism is less of a choice and more of a mandate):
Meat has a tremendous environmental impact. Dr. Joe has previously written about this but, to give you a hint, it takes roughly 54 calories of fossil fuel to produce 1 calorie of beef protein, while it takes only 2 calories of fossil fuel to produce 1 calorie worth of soy protein. Combine animals’ vast land, water and food needs, their methane expulsion (37% of all human-released methane), and the issue of what to do with their corpses once used up, and it becomes pretty clear that cutting down on, or eliminating meat is good for Mother Earth.
Once you start imaging cows, chickens and sheep as thinking, feeling beings, letting them live out their lives in battery cages becomes a lot less palatable. There are more ethical ways to get meat if you’re not willing to give it up altogether. Meat from free-range animals slaughtered in humane ways, fed good food and allowed to live into adulthood exists, but its heightened price tag makes it unpopular with the average consumer. Lab-grown meat is in development and may eventually be the answer we need but, for now, I’ll continue my five-year veggie streak.
I guess once you start questioning the sustainability and ethics of your meat-based foods, it’s natural to examine the effects on yourself and the world that your other foods might have. In that sense, vegans and vegetarians commonly advocate for fair trade foods, to ensure that their cup of coffee isn’t at the expense of an Ethiopian farmer’s welfare, a worthy endeavour. But they also often preach the benefits of organic and non-GMO foods, because non-organic and GMO foods are, if you believe many veggie bloggers, killing us and the world at large.
Despite the rigorous testing that GM foods must undergo and the building evidence that they are safe for both humans and the environment, vegan and vegetarian resources seem set on regurgitating the same myths about GMOs. This spreading of false information has created movements like the Non GMO Project, which has gotten so large that I can barely avoid it when buying my tofu or soy milk. I often find myself browsing blogs for a vegetarian dinner recipe, only to find unsubstantiated claims about how GMO foods are toxic for humans. Look, I wanted a spaghetti recipe with lemon, not nonsense.
It’s not that I’m not vegetarian for my health. Contrary to the preachings of what I like to call ‘bacon culture’, vegetarian and vegan diets are perfectly healthy for the average individual. Fruits and veggies have many health benefits, and the meat removed from a diet has to be replaced with something. It doesn’t escape my notice that a vegetarian diet is usually lower in calories and fat than one containing meat. But meat isn’t killing me anymore than is GM corn or non-organic soy.
Not all vegetarians are pseudoscience-believing, kale-munching, naturopath-visiting schmucks. I get my vaccines, eat GMOs, drink Diet Coke and eat too many French fries… I just don’t eat meat.
Hi! I’m Ada, and I’m a science-based vegetarian, but also an academic.
P.S. For some no-nonsense veggie- (and budget-) friendly blogs, check out these: