Why Does My Dog Scratch So Much?: How Diet Can Cause Itchy Skin

Dogs itch, which can be treated by that dog itch cream, and scratch all the time, but when scratching becomes excessive it might be time to seek help.

There are many reasons as to why your dog might be scratching so much, some simple, some not so much. Some causes of itchy skin include; skin infections, irritation, parasites, fleas or even boredom.

Did you know, that food allergies might also be to blame for your dog’s constant scratching?

Dogs respond to allergies in a different way to humans. A human exposed to an allergen often experiences acute swelling, which in some cases can be fatal! Dogs on the other hand often respond to allergens through their skin.

Canine allergies, food or airborne, can often lead to dermatitis (inflammation of the skin), which is why your dog might be continually scratching even though there is no apparent cause (such as fleas).

Diagnosing a Food Allergy

Diagnosing a food allergy isn’t an entirely simple proceedure, inflamed, itchy, red or flaky skin could be the result of any number of things. Unfortunately there is no simple test that allows for diagnosis of a food allergy, so the only way to truly diagnose whether or not a food allergy is the cause of your dogs itchy skin is through process of elimination.

Other possible causes of itchy skin, which must first be eliminated include:

  • Parasites
  • Fleas
  • Bacterial infection
  • Yeast infection
  • Airborne allergies (such as pollen)
  • Environmental factors (such as bedding, shampoo, etc.)

Diagnosis must also include careful consideration of the dog’s clinical history and any other symptoms presents. A primary candidate for a food allergy is a dog who is constantly itchy and fed a consistent diet throughout the year.

A dog fed a consistent diet is repeatedly exposed to similar proteins within that diet. Repeated exposure can cause allergies to develop in at-risk individuals.

Confirming a Food Allergy is the Reason for Your Dog’s Itchy Skin

To be sure that it is a food allergy that is responsible for your dog’s itchy skin, your vet will recommend feeding a hypoallergenic diet such as this hypoallergenic diet from Royal Canin.

Hypoallergenic diets contain novel proteins (proteins that the dog hasn’t consumed before). Feeding such a diet for 8 weeks will make it possible to determine whether your dog’s itchy skin is the result of a food allergy. After 8 weeks, if the skin has reduced in redness and flakiness, and your dog appears to be scratching less, then a food allergy is the almost definitely the root of your dog’s itching problem.

To fully conclude the diagnosis, the dog is usually returned to the original diet. If the symptoms return, we can confirm a food allergy.

This method of diagnosis requires complete compliance from the owner, this means the owner must ensure that the dog sticks strictly to the hypoallergenic diet – meaning no treats, no scraps and no supplements.

In some rare cases, a commercial diet may not be enough. Your dog may have an extreme sensitivity to certain proteins in food and they will require a prescription hydrolysed diet.

A hydrolysed diet contains proteins that have been broken down in to pieces so small, the immune system is unable to recognise them. As a result, this hydrolysed diet will not cause an allergy flare up that would result in itchy skin.

Breeds at Greater Risk of Developing Food Allergies

Some breeds of dog are more commonly seen with food allergies than others. We can assume that because of this, these breeds are more genetically disposed to developing an allergy. The breeds are:

  • Weimaraner
  • Boxer
  • Poodle
  • Chocolate Labrador
  • German Sheperd Dog
  • Dachshund

Dealing With Your Dog’s Food Allergy

If your dog is diagnosed with a food allergy, unfortunately, there is no cure. The allergy requires lifelong management.

Fortunately, hypoallergenic diets, such as this one, which can relieve your dog from the itchy skin associated with a food allergy, are not expensive.

Some other steps you can take to help calm your dog’s itchy skin include:

About James Watts

BSc Bioveterinary Science. Editor of PetSci. When I'm not writing, learning, discussing, or reading about animals, you know it's the weekend! Currently developing PetSci HealthTrak, the fast and easy way to monitor your pet's weight and calorie intake. HealthTrak offers a simple way to track your pet's progress, helping them achieve a healthy weight and a long, happy life.

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  1. my cici has been itching and scratching a lot for awhile now… she has white fur and pink skin and it has been an ongoing issue off and on… changed her diet, herbal shampoo for fleas, giving her salmon oil, using Dr. Harvey’s healing cream for the bumps she now has, doggy goo for allergies, and more… she has had some relief and then itchies come back again. not sure if she is being bit by critters, but the bumps did go away and came back again.

  2. Hi CeliaSue I am sorry to hear about your pet’s trouble.. How’s your pet now?.. Are you still struggling with this issue? If so, I can reply to you here or faster via email – Cynthia

  3. If anyone reading this is in the UK, try Aldi’s dried dog food, I’d given up on my 12 year old Border Collie’s dandruff / itching / discomfort after trying for many years to give her some relief. I don’t know what’s in this food, but within 3 weeks of starting her on it, the dandruff and itching has completely disappeared. The main ingredient is ‘cereals’ but I’ve a feeling it’s corn or rice rather than wheat, which she must have had a bad reaction to, even though no one could confirm this for all those years.
    It could be another ingredient in the many different foods she’s had over the years I don’t know, but she’s completely clear now, so she’s staying on Earls chicken flavoured dried dog food for the remainder of her years

  4. Hi. I have recently rehomed a greyhound. She is quite fussy with her diet. She loves chicken frames though, and as a general rule has one every morning as she prefers this to her Acana breakfast! She’s very happy to have her biccies at night. She has developed quite itchy skin and balding coat on her thighs. Also a loss of hair from under her neck. Do you think she is having too much protein or is she maybe ALLERGIC to chicken protein?? Otherwise she is really happy and bouncy 🙂 Many thanks, Aileen.

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