The Haslemere Pet Company

By Claire Goyer BA (Hons.), HND

Academic article submitted to the Animal Care College as part of Claire's continuing Professional Development.

We have all heard stories of owners avoiding certain foods because of a belief that they cause undesired reactions in their dogs.  The most common of these reactions include; hyperactivity, poor coat/skin condition and upset digestion. Although there is much evidence to support the idea that diet can contribute to these conditions, pin pointing diet as the root cause of such complaints is often a long and difficult task.

Identifying the manifestation of a diet related condition is usually the first stumbling block as most owners have not been trained to recognize what clinical signs will present with each condition.  Even labeling a dog as being “allergic” to a certain foodstuff is fraught with problems, as a true allergic reaction to food is actually a very rare phenomenon.

A true food allergy, or hypersensitivity, is an immunological response which can only be diagnosed by a series of veterinary tests. Food intolerance however, can be self diagnosed by observing a series of established symptoms and keeping a record of foodstuffs consumed by the dog.  By linking the two, the owner can comfortably deduce the offending culprits.

In the dog, adverse reactions to food usually manifest themselves in either skin or gastric complaints with a small number of cases presenting both symptoms.  The most common complaint is pruritus, the medical term for itching of the skin.   Dogs with pruritus engage in a “scratch – itch- scratch-itch” cycle which can lead to damage of the skin, and increased chances of infection.   However, pruritis can also be caused by a wealth of other factors including contact reactions to plants, flea infestations, or even a change in household washing powder, so it would be remiss of any owner to assume diet is to blame before first ruling any of these out. [1]

Other complaints which have been linked to diet include gastrointestinal (GI) disorders which can take the form of excessive/ loose stools, frequent passing of wind, and chronic diarrhea.  Diet can have a major influence in the occurrence of GI, as foodstuffs containing excess carbohydrates or inappropriate protein sources can trigger inabsorbtion in the small intestine causing the system to “remove” the offending material as quickly as possible.   As with pruritis, dogs suffering from GI complaints may also be reacting to other factors which may be unrelated to diet.  These can include gastroenteritis, reactions to recent drug therapies, or being offered too many tid bits from the family table. In these cases, simply feeding a bland diet for a set period of time, as well as cutting out inappropriate treats, may do the trick.  [2]

Hyperactively, commonly attributed to additives or excess protein, is another reaction that owners often associate with food.  This area is still controversial, as scientific evidence is fairly thin on the ground when it comes to dogs.  However, there has been quite a lot of research done on humans, but most of it links nutritional deficiencies with inappropriate behavior, rather than excess additives causing the problem. [3] 

Personally, I believe that this area is ripe for further study, and until more evidence is produced I would be loathe to combat a behavioral problem by simply changing diets.  Yes there is quite a lot of anecdotal evidence supporting the idea that diet can influence behavior, but any behavioral issue should always be resolved in combination with sound training/behavioral advice from an accredited individual, and not just on the basis of food.