www.pfma.org.uk

Food allergies and intolerances are two different conditions which often havesimilar symptoms. They are both examples of adverse food reactions, howeverfood allergies involve the animal’s immune system while food intolerances do not.

FACT SHEET

Food Allergy and Intolerance in Cats and Dogs

A particular component of food (usually a protein) triggers thesusceptible animal's immune system to react, for example cellsmay release histamine which causes itching.

Food allergy or hypersensitivity Food or dietary intolerance

Adverse Food Reaction

Something in the food doesn’t agree with the animal’s body but doesnot trigger the immune system to react, for example a dog may notbe able to digest cow’s milk well.

Itchy skin (also known as pruritus) and digestive upsets are themost common symptoms of an adverse food reaction, althoughear problems can also occur in some dogs. It is important toremember that these are all symptoms that can also develop fromnon-food allergies as well.

Common signs of Adverse Food Reactions

Allergies and intolerances are poorly understood in companion animals and don’t necessarily behave the same as similar conditionsin humans. Gaining an accurate diagnosis may take time and can be frustrating for pet owners, though ultimately rewarding.

Diagnosis of Adverse Food Reactions

Itchy skin is often not caused by food

It is common for people to assume that itchy skin is caused by afood allergy but true food allergies in cats and dogs arerelatively rare1; they are responsible for only 1% of all skindiseases in dogs2 and are only the third most common occurringskin allergy after flea-allergy and atopy (sensitivity to anenvironmental trigger like grass, dust or pollen)3.

1 Roudebush P, Guilford WG, Shanley KJ: Adverse reactions to food, in Hand MS, Thatcher CD, Remillard RL, Roudebush P (Eds): Small Animal Clinical Nutrition, Ed 4. Topeka,KS, Mark Morris Institute, 2000, pp 431-453.

2 Olivry T & Mueller R (2017) Critically appraised topic on adverse food reactions of companion animals (3): prevalence of cutaneous adverse food reactions in dogs and cats, BMCVeterinary Research, 2017 13:51.

3 Verlinden A, Hesta M, et al. Food Allergy in Dogs and Cats: A Review. Crit Rev Food Sci Nutrit 2006 ; 46:259–273.

FACT SHEET

Food Allergy andIntolerance in Catsand Dogs

www.pfma.org.uk

With instructions from a veterinary professional, an elimination diettrial should be conducted, to remove the suspected food allergenfrom the diet (including any treats and extras) for an extendedperiod of time. Keeping a food diary and a record of changes toclinical signs could be part of the diagnosis process. ‘Challenging’your pet with a food allergen to see if a reaction occurs is the finalstep in an elimination diet trial.

The aim of these trials is to identify the food allergen. This is hugelybeneficial as you can then avoid feeding it to your pet, which meanshe/she will be able to live a comfortable and healthy life.

There are a few options for elimination diets and your vet can helpyou decide on the most appropriate option:

• Hydrolysed diets are composed of very small protein molecules.The aim is for these small molecules not to be recognised by theimmune system, reducing the risk of an allergic reaction.

• Novel protein diets include a single protein source which the pethas never eaten before and therefore hasn’t developed an allergyto. Examples of novel proteins include duck, salmon, venison andwhitefish, or even more exotic ingredients such as kangaroo.

• Homemade diets are another option to control the ingredientsin your pet’s food. Preparing these can be time consuming anddifficult to balance, meaning they frequently provide inadequatelong-term nutrition. For this reason, homemade diets are oftenused as a temporary measure until the right pet food productis identified.

Types of Elimination Diets

Elimination Diets

Advice is at hand

Most likely protein sources causingAdverse Food Reactions4

In cats• Beef• Fish• Chicken

* Often a source of carbohydrates but also includes protein.

In dogs• Beef• Milk & dairy products• Chicken• Wheat*

Food allergies and intolerances can be serious medical conditions,affecting the health and wellbeing of your pet, therefore it is alwaysadvisable to seek veterinary attention if you suspect theseconditions. It is also important to read your pet’s food labelscarefully. To understand your pet food labels please refer to ourguide; PFMA Labelling Factsheet.

4 Mueller, Ralf S., Olivry, Thierry, Prelaud, Pascal: Critically appraised topic on adverse food reactions of companion animals (2): common food allergen sources in dogs and cats inBMC Veterinary Research, 2016, 12:9.

Please visit our website for a range of fun and informative factsheetsand posters on pet food and nutrition www.pfma.org.uk/fact-sheets