Is Your Pet’s Food Making Them Itch And Scratch?
As pet owners, we all know that it is perfectly natural for our dogs and cats to have the occasional scratch from time to time. Reoccurring or persistent itching and scratching can, however, be a sign that all is not well with your pet. Some pet foods contain ingredients that your pet may not be able to tolerate, and this can result in dry and itchy skin. Some of the most common ingredients that trigger this form of a reaction include; wheat, maize, corn, and dairy products such as milk.1Further, pet foods that contain grains and cereals can attract storage mites, a microscopic arthropod that can cause atopic dermatitis, especially in dogs. If you suspect your dog or cat may have an allergy, or, skin disorder, then examining their diet to ensure that any skin disorder is not being caused by your pet’s food, is essential if you are to identify the cause of the problem.
Studies have suggested that food intolerance is “the second most common cause of allergic dermatitis in cats and is considered responsible for up to 11% of cats with military dermatitis.”2 In dogs as many as 30% of dogs diagnosed with atopic dermatitis are also diagnosed with having a food allergy.3 Atopic dermatitis is a skin disease more commonly seen in dogs than in cats. It is the result of your pet reacting to specific allergens either found in the environment or ingested in their food.
- Frequently scratching of the ears and stomach
- Excessive licking or chewing of paws, abdomen and groin
- Reddened ears
- Reddened eyelids
- Hair loss (if left untreated)
- Black and deep pink pigmentation of the skin around the groin and armpits (if left untreated)
- Bacterial infections (if left untreated)
- Hot spots on the skin when you apply your hand to your pet’s coat
Whilst in many cases food intolerances will develop between the ages of six months old to three years in dogs,4 and between three months and eleven years in cats,5 it can occur at any age and it can take time for symptoms to develop. Some animals can remain on the same diet for many years without any difficulties and still develop an intolerance to their food.
Further, there is a need to distinguish between food intolerances and food allergies. Whilst the two terms are frequently used interchangeably, they are different. A food allergy causes an immune system reaction. A food allergy can be severe or even life-threatening, whereas food intolerances tend to be limited to digestive problems and less severe symptoms.
Some of the ingredients that more commonly cause allergic reactions and food intolerances in cats and dogs include wheat, wheat gluten, maize, and corn. All of these ingredients are difficult for cats and dogs to digest, especially cats. Cats do not produce the enzyme amylase, which is responsible for the breaking down of carbohydrates for digestion via the saliva, intestines, and pancreas.6 Dogs are capable of producing small amounts of salivary amylase so most are able to tolerate small amounts of poorly digestible carbohydrates such as wheat. If a dog or cat has an allergy to certain carbohydrates they will exhibit certain symptoms, much like with humans. The most common allergic reaction in dogs is the presence of dry skin, especially around the ears, feet, and muzzle.7 Cats react by developing dermatitis around the neck and face. Loss of fur is also a common symptom.8
Another ingredient found in pet food that can cause allergies and food intolerances in cats and dogs is lactose. Lactose is the sugar present in dairy foods including milk. Once a puppy or kitten has been weaned off of its mother’s milk the production of lactase, the enzyme responsible for the breaking down of lactose, slows down. Without suitable amounts of this enzyme present in the body, your pet cannot metabolise milk and is therefore intolerant to it. Being intolerant to milk is more likely to result in a gastrointestinal upset for your dog or cat. However, it is important to note that between 10-15% of animals with dermatologic signs of adverse food reactions may have concurrent gastrointestinal symptoms.9
Hidden allergens can also be a problem with food allergies. Mixed vegetable oils can contain a number of oils including corn and soy, two ingredients known to cause allergies in dogs and cats. So it is important to scrutinise the pet food label.10
It’s not just the ingredients in your pet’s food that can cause your pets to suffer from allergic reactions, it can also be caused by mites attracted to your pet’s food. If you are feeding a dry food that contains grains of any sort (including rice), then it is likely your pet’s food will attract storage mites. These microscopic arthropods are naturally attracted to dry foods, especially those containing grains and cereals. If your pet is allergic to storage mites, then their presence or even the remains of their faeces can cause atopic dermatitis. It is incredibly hard to prevent storage mites from infesting your pet’s dry food. The most effective course of action is to change your pet’s diet to a dry grain free alternative, or, to a grain free wet food or raw food diet. You should also ensure that any treats you feed your pet are grain free.
If you believe your pet is showing the symptoms of food intolerance, or, an allergy and you decide to change their food, there are certain steps you should take. The first is to ensure that any new food does not contain any cereal or grain. Pay particular attention to the lesser ingredients as well as the ones that make up the bulk of the food. Often even small amounts of a particular ingredient can trigger an allergic skin reaction.
Once you have chosen a new food, introduce it to your pet slowly. Introducing a new food too quickly can result in your dog or cat suffering from an upset stomach and may result in them going off of their food. Instead, begin by adding a small amount of the new food to your pet’s existing food, and then over a period of a few days increase the amount of the new food while decreasing the old food. If your pet has sensitive digestion we would suggest you make the change over 2-3 weeks.
If your pet is showing signs of atopic dermatitis or other allergic reactions it is advisable to seek veterinary advice.
If you wish to find out more information on storage mites, we have provided a more detailed article in our Advice Centre.Back