What should be in your pet food – (PART 0)
Let’s start from the basics of the dog and cat’s biology to understand what should be in the pet food. However, before we do that, here’s a quick story. A customer asked for a great pet food that we explained was discontinued due to lack of demand despite educating new owners.
Her response was “they don’t have an older pet.”
When pets are younger, it seems that you can feed them pretty much anything.
They may seem resilient and we expect they will not encounter any major health issues.
However, years down the road when they are not just pets but integral members of the family, it can be a shock that they develop bowel disease, diabetes, kidney disease or pancreatitis to name a few. We often forget that what we feed them or put in their bodies chemically can cause these issues. Note that we are not saying that food is the only factor that can cause or mitigate diseases. Other factors such as genetics, activity level, immunization and environment can have an impact on your pet’s life.
What dogs and cats need from pet food
Dogs and cats are carnivores. Cats being obligate carnivores while dogs are adapted to carbohydrates. Cats have no salivary amylase for carbohydrate pre-digestion while dogs have little salivary amylase. All this means is that they should be eating primarily meat. Physiologically, the teeth of dogs and cats are meant for chewing/ tearing meat & grinding bones.
In addition, they have shorter digestive tracts, as they don’t need to break plant matter, which takes a longer time. The stomach pH of dogs and cats are also more acidic to help them digest meat and bones better.
Now that we’ve established that base line, the second issue is not all proteins are created equal. For example, your pet’s food could have 40% protein but a portion could be provided by soy, peas or meat by-product. Meat by-product could include animal hide and hooves. Although you have a high protein content (called biologic value (BV)), these are not easily digestible forms of protein for cats and dogs.
Soy has been used as an inexpensive way of adding protein (BV of 67%) to pet foods. However, it is not a species-appropriate pet food, which means dogs and cats won’t naturally seek this out as food. Using soy also ignores that it can cause food sensitivities, potential hormonal issues, and interfere with thyroid function. However, don’t congratulate yourself yet if your pet food does not have soy or peas in it.
Proteins are only important because of the 22 amino acids that both dogs and cats need to be healthy. Amino acids are the building blocks of proteins. Dogs can produce 12 of these amino acids on their own while cats can only make 11. The remaining amino acids that pets need to get from pet food are:
In terms of plant protein, Soy is a good source of Lysine and Tryptophan.
Note that as your dog gets older, their requirement for proteins go up even in animals with kidney disease. A study by Dr. Delmar Finco, showed that “mortality was actually higher in the low protein group”1 for dogs with renal disease where “there were no adverse effects of the high protein diet.”2
Next in terms of need is Fats, which is rich in energy and provides the essential fatty acids (omega 3 and omega 6s).
Omega-3 fatty acids tend to have an anti-inflammatory benefit and common sources tend to be flaxseed oils and fish/krill oils. We’d suggest the krill oils are better as they have the antioxidant Astaxanthin but you could rotate between these sources.
Vitamins and minerals in our pet’s food
These are essential for life.There are 2 types of Vitamins:
- Fat soluble Vitamins – (Vitamin A,D, E and K) – they can accumulate in the body and become toxic.
- Water soluble Vitamins – (Vitamin C and the B vitamins i.e. thiamin, riboflavin, niacin, pantothenic acid, pyridoxine, biotin, folic acid, cobalamin) – they are not stored in the body and can be eliminated through pee.
You’ve probably seen some of these on the dry pet food bags. However, we will write another blog to cover synthetic vitamins vs. natural vitamins later. It is important to note that vitamins are sensitive to light, heat and oxidation so pre-packaged vitamin mixes must be handled carefully.
To simplify Fat Soluble vitamins, here’s a nifty table
|Good Sources||Key function|
|Vitamin A||Liver, fish, eggs||Vision, skin and hair|
|Vitamin D||Sunshine, oily fish (tuna) and liver||Bone growth|
|Vitamin E||Cold pressed vegetable oils, liver||Antioxidant|
|Vitamin K||Intestinal bacteria in pets can produce this but not in sufficient quantities. Liver, meat, kelp, egg yolk||Blood clotting and normal blood functions|
For the Water soluble vitamins, Vitamin C is not required as dogs and cats can make their own. However, Vitamin C has been considered to prevent hip dysplasia and urinary tract infections. Common sources include citrus fruits.
The B vitamins, play a wide role in nerve function, skin, hair, growth, cell energy and formation of blood cells. Good sources of these vitamins tend to be found in organ meats, tripe and from yeast as well as wheat germ.
Minerals are the inorganic component of the diet, which are necessary for bones, blood, skin and other important functions. When you analyze pet foods, it is referred to as ‘ash’ which is what is left over after the food is burnt. Here is a quick list without going into too much detail about what each is for: Calcium, Phosphorous, Magnesium, Chloride, Sodium, Potassium, Iron, Zinc, Manganese, Copper, Iodine and Selenium.
Common sources include animal bone, meat, fish, eggs and for some minerals, you can find them in green vegetables e.g. broccoli and spinach.
Wait! Don’t go to the store and pick up the bag of pet food with the highest ‘ash’ content just yet.
Water for optimal health
Your pet also requires water/moisture. It is a major part of the animal’s body and can be obtained primarily by either drinking or eating. It is important to always have fresh water available for our pets and this component is one that it is important to have the right amount. As cats are desert animals, they tend to get most of their moisture from their food. Dogs and cats may not be drinking enough if they are on a dry food. That will put more stress on their organs as they age.
So how about Carbohydrates in pet food for dogs and cats?
Technically, it is not an essential nutrient for dogs and cats as they make their own glucose from amino acids. So why is it added to many brands of dry pet food? Aside from being a cheap source of energy, it is used as a binder to get those little kibble shapes and also provide some fiber.
Let’s create a rule – if you are to going to feed any carbs for dogs and cats, it should be minimal.
Is that all that pets require?
Usually at this point, other analysis on pet food that we see stop. Look at the back of most dry pet foods and you will see that they are likely missing the next 2 components: guaranteed probiotics and enzymes.
- Enzymes – these are typically made by your pet’s body (pancreas) or can be found in pet food. Enzymes help digest and use food efficiently and are responsible for a countless number of functions related to the immune system. Without the help of enzymes, your pet will have problems digesting proteins (protease), carbs (amylase), and fats (lipase). When your pet’s body is depleted of enzymes, there is no going back. Note that like most of the other necessary building blocks, enzymes are destroyed by heat.
- Probiotics – these are the helpful, beneficial bacteria in your pet’s intestines that ensure good health and digestion. Two sources of probiotics are:
- your pet’s food (if it is not subjected to heat) and
- within your pet’s intestines.
In our next blog, we’ll try to put this all together as a benchmark.
To use a poor metaphor, the fuel you put in your car matters when it is new to ensure longevity. This metaphor breaks down on several fronts when it is applied to our dogs and cats.
They are complex beings and the fuel they consume matters enormously in building the necessary structure for a healthy life.
The above information should set up the prologue for the next three blogs on choosing pet foods:
- Beyond Grain Free; Is kibble sufficient for your pet’s health?
- How to choose raw pet food? Can you get all these basic goodies from raw food?
- The V-word. Is Veganism for cats and dogs?
1, 2 Delmar R. Finco, DVM, Ph.D., “Effects of Dietary Protein Intake on Renal Functions” 1992