Understanding your dog’s food
A four-part blog series exploring and demystifying the information on your dog food packaging
Part 1 – Reading the Packaging; Analytical Constituents – “why is there ash in my dog’s food?”
Many dog owners find choosing a suitable dog food a bewildering and confusing experience. A multitude of bags and packages, some with very pretty pictures and graphics, often brightly coloured and covered in lots of information can make decision making difficult. It becomes even more problematic when certain terms such as “natural” and “species appropriate” are used on packaging to try and encourage the consumer to purchase one product over another. Even the important information that relates to the nutritional value of the food for your dog can be difficult to decipher!
So, how do you decide what food to feed your dog? What information is useful and what information is there to try and manage your spending behaviour and might not necessarily be in the best nutritional interest for your dog? This series of articles aims to demystify some of the information that you will find on your dog food packaging and to bust some of the myths around that information.
In this article, we will explore the term “analytical constituents” and what it really means for your dog and why the “analytical constituents” can be an important consideration in choosing a food.
On every package of dog and cat food, you will see a section called “Analytical Constituents”. This section then lists percentage amounts in the food of “crude protein”, “crude oils and fats”, “crude fibres” and “crude ash”. These are terms that must be declared on packaging of pet foods and represent the chemical analysis of the nutritional value of the foodstuff. The term crude is not a negative term, nor does it suggest poor quality, rather it is simply the scientific term used for the methods used to analyse the specific amount of each of these components within the food. The analytical constituents are declared as percentages and permit consumers to compare one food against another in terms of these nutritionally important components.
Protein is essential in an animal’s diet to permit growth, repair and regeneration. Much of the body consists of protein and it is important that a good, quality supply of protein is supplied by the diet to replace that used daily in normal biological activities. Protein can be supplied in a dog’s diet from both animal and plant sources, with many grains being excellent sources of protein. Indeed, the building blocks of proteins are called amino acids and some plant proteins are better sources of specific amino acids than some animal proteins! This is where good dietary formulation is critically important, and it should be remembered that a dog requires nutrients and ingredients supply those nutrients. In the case of protein, amino acids are what are needed and a balanced supply of proteins from both plant and animal sources can be an efficient and effective way for supplying those amino acids to your dog.
The percentage of crude protein in a diet does not tell you if the protein has come from plant or animal sources, nor does it indicate the overall digestibility and thus the biological value of the protein to your dog. It does however give you an idea as to the nutritional value of the food and many healthy dogs with a moderate activity level do extremely well on a food with a crude protein level of about 18%. However, dogs that are highly active, pregnant/lactating bitches, dogs recovering from illness/surgery, growing dogs or very old dogs often benefit from diets with higher levels of protein. This is to support their bodily demands and often diets are specially formulated to assist these life stages. For most dogs, higher levels of protein are not necessarily always better – your dog may have to excrete any excess dietary protein, and this can be costly both in monetary cost (protein is typically the most expensive component in a foodstuff!) as well as for the environment in terms of sustainability and the excretion products of protein digestion, notably urea and ammonia. It’s worth seeking qualified nutritional advice if you are unsure about your own dog’s nutritional protein needs.
Crude oils and fats
In the same way as crude protein, the term “crude oils and fats” simply refers to the chemical analysis of the overall fat and oil content of a foodstuff. It is not an indication that food manufacturers add crude oil from the North Sea to their foods! Fat (oil being liquid fat) is essential in an animal’s diet and dogs especially use fat as a primary source of energy. On this basis, often foods formulated for highly active dogs have higher fat levels than those intended for more sedate dogs; for example, Field and Trial Superior which is intended for highly active dogs has a crude fat content of 20%, compared with Field and Trial Light and Senior, with a crude fat content of only 8.5%!
Typically, as the crude fat content of a diet increases, the crude protein content also increases, to support the dog’s activities overall, including the ability to digest the dietary fat! For many dogs however, the fat content of a diet needs to be limited as it is linked with obesity. Indeed, choosing a food with a low percentage of crude oils and fats is an easy way to help manage your dog’s weight via diet.
Crude fibre is an indication of the fibre content of the diet and again is a measure of the composition of the diet based on laboratory tests. Fibre is typically from plant sources and is the indigestible part of grains and other plant products. Fibre is useful for maintaining gut health and stability. Fibre within the diet of a dog can help regulate the functioning of the gastrointestinal system and can assist in the production of firm stools and help naturally empty the anal glands. Indeed, high fibre diets are sometimes useful for dogs with ongoing anal gland issues and certain other medical conditions.
Fibre is sometimes erroneously called a “filler” when in truth, there is no such thing as a “filler” in nutritional formulation. All ingredients within a food are there either for nutrient provision or other functional reasons. The crude fibre percentage can be another useful way of selecting a food to support the overall health and welfare of your dog, but a high crude fibre percentage is not necessarily an indication of a poor-quality food. Instead, it might be a food specially formulated to support digestive health or weight management, where fibre can have significant benefits.
The term “crude ash” is one that leads to much confusion. Thankfully, it does not mean that ash is added to pet food! Rather this term indicates the chemical analysis of a foodstuff to measure its intrinsic mineral content. The term “ash” is used because the analysis method involves burning the food until only the non-combustible parts of the food are left as ash. This ash fraction is the mineral part of the diet and includes key nutrients such as iron, calcium, phosphorus and copper. Sometimes the term “crude ash” is replaced by the terms “inorganic Matter” or “incinerated Residue”, but they all mean the same thing and it is important to note that ash is not directly added to the food.
The ingredients within a dog food will affect the crude ash level and, on this basis, a higher ash level in one food compared to another is often a result of different ingredients, rather than an indication of poor quality food. Indeed, a higher crude ash percentage suggests provision in the diet of more key minerals and will often be found higher in foods formulated for puppies and adolescent dogs, as well as in foods that contain protein from beef and lamb origin. In the next article in this series, we will explore the ingredients list on your dog food and examine the value of understanding what goes into a food and in what amounts.