Dog Nutrition

Understanding Dog Food and How It Can Affect Our Dogs by Alex Wilson

There are many different dog foods on the market today, compared to years ago today’s pet owner has some great choices out there to meet budgetary requirements as well as what is in the foods. Tellington TTouch practitioner, ALEX WILSON looks at how to analyse dog foods to make sure your dog is getting the best that they need and looks at the effect of food intolerances. 

Reading the label of a tin of dog food or the bag will determine how good or bad the food is but the analysis provided can be confusing especially if you are trying to compare a wet food with a dry food. As a general rule, dry food will be the most economical to buy but will it be the best for your dog? Another valid point is that the lower the price of the food the more you are going to feed each day to the dog, so your price per Kg or lb. might be lower but your price per meal will be higher as the budget brands will contain less meat an expensive ingredient.  The ingredient listed on the food will tell the whole story. Beware that publishing full ingredients on small bags is not compulsory, only on bags over a certain weight and many pet food companies do just that.

If we were to try and compare a dry and a wet food the first thing that we need to do is to convert the dry matter of the food in each example, this will vary whether you are feeding a dry food, a canned food or a raw food – canned or raw diets will have a much higher level of moisture. On average a dry food will have 10% moisture – generally, the moisture level is not provided by the manufacturer. A wet food more like 78% moisture and can usually be found on the analysis of the food on the label. The moisture levels that are stated on the wet food are based on as it is when it is being fed, not on the basis of dry matter so we need to convert the three foods moisture levels to the dry matter to be able to provide an accurate comparison – This takes a small amount of maths!

A Good Quality Dry Food – we will assume that the moisture level is 10% so we can assume then that the dry matter accounts for 90%. Now we take the protein percentages within the food that accounts for 26% and we divide it by the dry matter (90%) to give us the figure of 28% protein on a dry matter basis.

Good Quality Tinned Food – The moisture level is 71% so the dry matter will account for 29%. The protein levels are 8.4% and doing the maths gives us 29% protein on a dry matter basis.

Raw Barf food – The moisture level is 73.1% so the dry matter will account for 26.9%. The protein levels are 12.3% so doing the maths gives us 46% protein on a dry matter basis.

From this, we can see that although we are looking at three good quality dog foods in a similar pricing bracket, the protein levels of the dry and the tinned food are similar but the raw food has a much higher protein level.

We are able to do the same thing using the same formula to analyse other ingredients of dog food for example.

Fat Content

Dry 13% fat on a dry matter basis

Tinned  29% fat based on dry matter

Raw 37% fat based on a dry matter basis.


Many dog foods that claim to have no added preservatives may choose to buy in ingredients that are already preserved.

Vitamins are often used as natural preservatives: Vitamin A 22,500 IU, Vitamin D3 1,800 IU, Vitamin E 700 IU. Vitamin E is a natural found in many foods that can act very effectively as a preservative. Low-grade pet foods often use synthetic preservatives and there is evidence to show that these can interfere with bitches heat cycles.

In conclusion, there is no “best” dog food on the market it will all depend on the individual dog, their lifestyle, the amount of exercise they take etc. Some need higher protein and fat levels some prefer tinned food over dry. Raw may not be a suitable option for some households.

The possible signs and symptoms of food intolerance.

Food is not the only thing that causes allergies in dogs, in fact, it only accounts for around 10% of all allergies that dogs can suffer from. It is the third most common cause of allergies after fleabites and inhalant allergies.

When talking about intolerance we need to understand what we are talking about allergies or sensitivity as there is a big difference. Let us first address allergies. This is usually a negative response to the protein in the food, which can cause anything from chronic diarrhoea to loose poo, itchy skin caused by inflammation, coat loss, chewing between the toes, hotspots, ear infections or even runny eyes. The best solution to helping these allergies is to change the dog’s diet to a lower protein diet and/or to change the protein that the dog is eating.  For example our Dalmatian, who is raw fed and having a mixture of a number of different meats including meat and poultry was getting a lot of mucus in her poo and was becoming very vocal. By changing her diet to poultry only we managed to both eradicate the mucus from her stools and it cut down much of her excessive vocalisations. There are certain foods that more commonly can cause allergies in dogs and scientific studies have shown that the following are often causes of allergies: beef, dairy products, chicken, lamb, fish, eggs, corn, wheat and soya. Many of these ingredients are commonplace in many processed dog foods.

With food sensitivity the symptoms are pretty similar but it is caused by sensitivity to an individual or a number of ingredients within the diet rather than the amount of protein or the type of protein – the best solution with food sensitivity is to feed a diet with fewer ingredients or eliminating various ingredients so that these foods are not in the diet.

As a pet owner, it makes little difference if your dog is suffering from food allergies or food sensitivity (if you were treating it as a vet, they might look in more depth at the difference.)

When looking at the problem the first thing to understand is what are you feeding your dog, this will include the meals that they are receiving, any treats and any supplement, for example, many of us give our dogs Glucosamine products if they have bad hips or joints and this product derives from Green Lipped Mussel. If we are to go for a 100% change in the diet we need to consider that there are some ingredients common to many foods so we are best to try and change individual ingredients. This can be done by having a full understanding of what is in the diet we are feeding, help can we found at or by preparing your dog’s food yourself.

Another consideration when thinking about food intolerances is the link between food and behaviour. I can often spot a dog at 100 yards that is fed on a low-grade food readily found on the shelves of your nearest supermarket, rather than a food recommended by your pet shop or trainer, by its hyperactivity, its lack of being able to concentrate and in many cases its high arousal level.

Australia vet, Bruce Syme writes that the links between animal behaviour and food has not been properly researched and is pretty unclear. What we feed ourselves has a dramatic effect on our behaviour which is why we are always told to eat our 5 a day. Removing processed food from a dog’s diet can in some cases have a marked change in the way that dog behaves, its ability to learn and its ability to cope with situations that it has to encounter. This might be down to the removal of the preservatives, colourings and flavouring or it could be down to the fact that the dog is getting a better quality of food especially if that change is to a high-end food or a raw diet.

Anxiety, hyper-excitability, even aggression in some dogs can be helped by a change in diet, changing from a processed diet to a natural or raw diet. In the 1930s Dr Pottenger conducted research with cats that showed that those fed on a cooked diet showed more signs of aggression to other cats and their handlers compared to those fed on a raw diet. When the cats that were fed on the cooked diet had their diet changed to raw, Dr Pottenger saw changes in their behaviour with less aggression.

There is also evidence that separation anxiety can be linked to food allergies or sensitivities, veterinary behaviourist Dr Gabrielle Carter worked with her dog who suffered from food allergies and separation anxiety and after she changed her dog to raw feeding there was a marked improvement in the food allergies as well as changes in the separation anxiety. I am not saying that this was totally down to a raw diet, the same might have happened if the dog had had its diet changed from a low end processed food to something good.

Dr Syme also explains,

“…raw meat does improve the natural improve the natural levels of 5-hydroxytrptophan, which is the body is natural precursor to produce serotonin (a neurotransmitter), which has a powerful impact on mood, and other behavioural traits…”.

In conclusion, there are two things that we need to consider when thinking about food intolerances.  Firstly there are the physical issues caused by the dog either being allergic or sensitive to foods that they are eating. These things include upset stomach and diarrhoea, increased size of the dog’s excrement, it is interesting to note how small the poos are from a raw fed dog compared to the poos from a dog fed say on a cheap budget diet. The dog may also have a lot of wind, itchy skin, runny eyes; they may lick their paws or scratch their ears a lot. They may even be touch sensitive. Some dogs may also be fussy feeders and not terribly interested in their food

Then there is the behavioural effects; excessive barking, high arousal levels, hyperactivity, biting, mood swings, tail chasing, lack of an ability to learn, amongst others.

Technically dogs are omnivores so like us they need balance in their diet. The fact that many dogs will eat just about any things does not mean that they would be better off with a balanced diet of meat and plant matter.


Further reading download this excellent ebook, free, just click right


They are What They Eat, a simple Guide to dog nutrition by Kerri Bee

 Dog Food Labels – Drs Foster and Smith Educational Staff

 Links Between Behaviour and Nutrition Dr Bruce Syme

Nan Arthur’s Whole Dog Training – How Does Diet Affect Behaviour in Dogs

 Impact of nutrition on canine behaviour: current status and possible mechanisms – G Bosch, B Beera, WH Henriks, AFB can der Poel, MWA Verstegen – Nutritional Research Reviews (2007) 20. 180-194