Help! Does my dog have a food allergy?

With the prevalent marketing of all-meat and raw feeding for dogs, many pet parents assume that avoiding non-meat-based “additives” is the best way to prevent food-related skin and gut problems.

They are often surprised to learn that most of the main allergens in dogs are actually animal products, with beef at the top of the list in the UK, followed by chicken, dairy and wheat (Source).

The top allergens in a particular region may vary over time, and they tend to be closely related to common ingredients in that region.

Diagnosing a food allergy is notoriously difficult. Pet parents often report that they know their dog has a problem with a particular ingredient, such as corn, because the problem appeared to resolve in the week a corn-free diet was fed but returned when they tried a different diet a few days later. Unfortunately, food allergy diagnosis takes a lot longer than a few days, and a food trial with an elimination diet is currently the recommended approach.

WHAT IS A FOOD TRIAL?

A food trial with an elimination diet means feeding a diet based on a novel protein (i.e. one the patient has not eaten before) or a hydrolysed protein (when the manufacturer has processed the proteins so they’re too small to cause a reaction) for at least six weeks, with some sources recommending around twice as long. For the purpose of the trial, a commercial diet is more likely to be complete and balanced than a home-prepared diet. If there is an improvement, the patient is then challenged with the suspected culprit food, followed by the gradual reintroduction of individual ingredients to see which one provokes a reaction (Source). 

For the duration of the food trial, no other food can be given, including treats and flavoured medication. As anyone with a food-motivated dog can attest, it’s extremely hard to enforce this! Dogs are experts at sniffing out and snatching food on the sly. In the two seconds it takes you to read a text message while you’re out walking Charlie, he can easily swallow that cheese-flavoured corn chip that someone dropped beside the footpath, and you wouldn’t even be aware that he’s just managed to undo the past three weeks of meticulous meal planning.

Further complicating matters is the fact that truly novel proteins have become more difficult to come by. Meats previously recommended for food trials – such as venison, kangaroo and lamb – are increasingly being used as ingredients in dog food and treats. Read through the ingredients of an ordinary dog food, and there’s a good chance you’ll find protein sources that have nothing to do with the primary flavour printed on the label.

SO WHAT CAN BE DONE FOR DOGS WITH A SKIN OR GUT PROBLEM RELATED TO FOOD?

The first step is to recognise that it’s often something else, as food allergies are not as common as many clients believe (Source). Flea saliva, environmental irritants, nutrient deficiency, atopic dermatitis (familiar to human eczema sufferers), a hormone imbalance and even anxiety are among the other common culprits. Ensure that your dog is currently on quality parasite prevention, and talk to your vet about basic tests.

If your dog has a confirmed food allergy, careful planning is required. For example, if your dog has a beef allergy, avoiding beef-based dog food is only part of the management strategy. Other components may include the following:

• Aiming to find food not produced in the same facility as beef-based dog food to minimise the risk of cross-contamination. (Herbie Wilde is one brand that does not manufacture any products containing animal ingredients on its lines, with the exception of lanolin-derived vitamin D3 in accordance with UK requirements.)
• Removing beef products from the house, if possible.
• Monitoring your dog around children or in public places to guard against ingestion of dropped food.
• Avoiding medication and parasite prevention flavoured with real beef.
• Seeking out meat-free treats as rewards.
• Visiting your veterinarian for annual health checks to stay informed of the latest developments and advice, as this is an evolving field.

WHERE CAN I GO TO FIND OUT MORE?

Every veterinarian and veterinary nurse has studied nutrition, but many have done additional study (formal or informal) on top of this, so explain that you want to discuss nutrition when you make your appointment so the receptionist can book you in with the most suitable person at the practice. A veterinarian can also refer you to a veterinary dermatologist or internal medicine specialist to further investigate other causes of your dog’s problem.