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. At least five different studies 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. Several studies have shown 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.