Reading labels

UNDERSTANDING DOG FOOD LABELS

Dog food labels can create confusion for owners looking to understand what they need to feed their canine companion.

In this article, we will focus on how to use the information available to ensure that your dog is getting all they need from their diet.

DIFFERENT TYPES OF FEED

A 'complementary' dog food is exactly what it says, in that it supplements the diet but does not provide a full and complete balanced diet.

On the other hand, a 'complete' feed should contain all of the essential nutrients at levels that meet the dog's requirements. With complete feeds, if the dog eats the right amount for their energy requirements, their nutritional requirements for all other nutrients will also be met.

NOTE: Some 'complete' feeds will be labelled as 'Complete and Balanced for All Life-Stages'. In essence, this means that the food is suitable for phases of growth, as well as for adult and senior dogs. This is a tricky claim for a food company to make and should make owners wary. There are huge differences between the needs of a puppy and the needs of a senior dog, and one food that can meet them all is difficult to conceive of. For this reason, most of the leading dog food brands now offer a range of foods aimed at different age groups and different activity levels, e.g., puppy food (growth), adult food (maintenance), less active (weight control), or a senior diet (reduced calories with more fibre) etc. This targeted approach is a better option in most cases than a one-size-fits-all food.

INGREDIENTS

The ingredients list alone should not be used to decide whether a particular dog food is the best option for your dog. There are two main reasons why:

• The ingredients list places everything in order of weight, so the ingredient present in the largest amount should come first on the list. Based on this it is then easy to think that if meat is listed as the first ingredient, the food is a good option. However, seeing meat at the top of the list simply means that the main component of the food is meat, but does not consider the quality of the ingredients. Individual ingredients vary significantly in protein quality (whether the complete range of essential amino acids is present) and their digestibility. Suppose we were to compare a premium brand with a budget brand that contains poor quality ingredients with low digestibility - the ingredients list could look the same, despite a vast difference in the food quality.

• The way certain ingredients are presented can be misleading. Manufacturers may split up different forms of similar ingredients so that they are listed separately on the label and appear further down the list. For example, the overall wheat content may appear lower if it is split into wheat flour, ground wheat and wheat bran etc. If these were listed as one entity, then wheat would contribute a large proportion of the food, which may not be a desirable option.

CARBOHYDRATE

One thing that manufacturers do not necessarily show is the amount of carbohydrate present in the food. They will usually only state the crude percentages for fat, protein, ash, fibre, and moisture. To work out the carbohydrate percentage, simply add all these other numbers up and take them away from 100. What is left is the percentage of carbohydrate in the product. This can then be converted to a dry matter basis as per the calculation above.

COMPARING FEEDS

Things become a bit confusing when you try to compare feeds because the 'as fed' percentages of protein, fat, fibre and ash do not consider the food's moisture content. We need to convert these 'as-fed' values to a dry matter value to be able to compare feeds accurately. This is especially important if we want to compare, for example, the percentage of protein in a dry food with the percentage in a wet food. To do this, there are two steps, which involve a bit of maths.

STEP 1 – WORK OUT HOW MUCH DRY MATTER IS PRESENT

The first part of the calculation is simple and relies on subtracting the percentage moisture from 100 to give the percentage dry matter. For example, in wet foods, the label may state 25% moisture, meaning that there is 75% dry matter. In dry foods, the label may state 10% moisture, meaning that the product is 90% dry matter.

STEP 2 – CALCULATE

To proceed, you then divide the percentage of nutrient stated on the pack (as-fed) by the percentage of dry matter.

You then multiply your answer by 100 to give the percentage of that nutrient on a dry matter basis.

For example, to work out the percentage of protein:

If a dry food contains 10% moisture and 25% protein (as-fed)

• This means that the product has 90% dry matter: 25 divided by 90 = 0.28

• 0.28 x 100 = 28% protein on a dry matter basis

If a wet food contains 25% moisture and 25% protein (as-fed)

• This means the product has 75% dry matter: 25 divided by 75 = 0.33

• 0.33 x 100 = 33% protein on a dry matter basis

We can, therefore, now compare the wet and dry foods, which initially looked to have the same percentage of protein. In reality, the calculations show that the wet food contains more protein (33% versus 28%).

WORKING OUT NUTRITIONAL REQUIREMENTS

By law, packaging has to guide how much to feed, but this is simply a guide and usually takes no account of age or activity levels. We can work out our dog's energy requirements using some more simple maths to get around this. If the food is a complete food, it will have been designed to ensure that all other nutrient requirements are met if energy levels are met, so we only need to work out the energy requirements.

For active adult dogs:

• Energy needed (calories) = 130 x weight (in kg) THEN multiply by 0.75 For inactive adult dogs:

• Energy needed (calories) = 95 x weight (in kg) THEN multiply by 0.75

The packaging may not tell us how much energy (calories) there is in 100g of the product, so we need to know this to work out how much to feed. If you have already changed the 'as-fed' percentages of protein, fat and carbohydrate into their percentage on a dry matter basis, then you have already done most of the work.

It is the protein, fat and carbohydrate which provide energy (calories). Every gram of carbohydrate present in the product will give 3.5 calories. Each gram of fat will provide 8.5 calories, and each gram of protein will provide 3.5 calories. Then all we have to do is multiply as follows:

• Percentage protein on dry matter basis x 3.5

• Percentage fat on a dry matter basis x 8.5

• Percentage carbohydrate on a dry matter basis x 3.5

Add these up to know how many calories are in 100g of the food. From this, you can work out how many grams to feed according to their energy requirements.

TAKE-HOME MESSAGE

While the maths can be a little off-putting, the bottom line is that these calculations will ensure that you choose the best food option that works for the age and activity level of the dog. It's great to know that your decision is based on real facts rather than simply the marketing claims of the product.