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Canine Allergies: What causes them and how can we control them?


Have you ever had an itch that didn’t matter how much you scratched?  Have you ever had a rash or sneeze attack after being in the garden or park?  Well, you are more like your furry companion than you think!

They too deal with allergies but they often can’t tell us.  So it is our job to know what to look for and when to take action to help our buddies “scratch that itch”.

Let’s talk about 3 things for each type of allergy:  how to know when your pet is dealing with allergies, how are they diagnosed and, finally, what can we do to treat them.

Types of Allergies

To know when your pet is having allergies, we have to understand the types of allergies that are out there.  There are 4 common types that you need to look for:

  • Fleas: Yes, fleas! It may sound cliché but remember, fleas are still a major cause of allergies in dogs. Fleas bite and their saliva causes itching anywhere from 15 minutes to 2 days after fleas bite your dog. Even if you have not seen fleas in your house or on your dog, fleas may still be the culprit, especially if they are not on monthly flea prevention. And yes, even if your dog “doesn’t go outside.” The reaction that a bite causes is called Flea Allergy Dermatitis (FAD) by veterinarians.

    • What to look for:

      Signs of this are itching, irritation, loss of hair specifically around the hind end, base of the tail, thighs and belly.  You may also see a flea or “flea dirt” along the back from the hind end through the shoulders.  This brownish dirt is actually blood digested by the flea and left along the back.  So yea, flea poop (gross)! If you have any of these, fleas should be up on your list to talk to the vet about, especially if your dog is not on a current flea preventative.

    • What to do:

      If you have seen any of these things, talk to your vet about checking and treating for fleas.  Flea treatments can range in duration from one month to three months and generally do a good job of keeping fleas at bay.  Flea shampoos are a great supplemental treatment, especially when you have seen fleas actively on your pet.  Your vet may also prescribe something to help with the itch when you start the preventative also. Some example of flea prevention include, Nexgard, Bravecto, and various monthly preventions that also include heartworm and tick prevention. Flea prevention is recommended yearly in many parts of the world, even during the cooler months.

      It can be really tricky to get a flea infestation under control, despite using topical flea treatments on your pet. This is because fleas only hatch in warm conditions and often the eggs are found under furniture or in bedding. They may not hatch right away if conditions are not right so this is extra cleaning can be really helpful. They love dark areas in your home and especially where your pet sleeps. Here are some tips to improve

      • Vacuum more frequently to remove fleas and any eggs before they hatch
      • Wash all pet beds or blankets in hot water
      • Pet-safe/home-safe pesticide sprays
  • Another common, and frustrating allergy that our pets deal with is environmental allergies. Vets call this atopy. Atopy is one of the top reason for veterinary visits in the US. This is when something in their environment irritates their skin. This can be pollen, plant material, things in the air or even things in the home like dust mites. Most people know how frustrating and uncomfortable this can be! Any dog can be at risk for this, couch and passenger princess pets included. The air can bring in allergens through windows or carpet can harbor dust mites.

    • What to look for:

      Just like any of the allergies, the signs can show up anywhere on the body but mostly itchiness, redness, scratching and hair loss is often found on the paws, face, arms and legs, belly and ears.  Dogs will show signs of itchiness by shaking their heads and licking their paws too, not just by scratching and chewing. These allergies can be year-round but may be worse at some times of the year.

    • What to do:

      Trying to find out what is causing this allergy can be frustrating.  It may not be easy or even possible to figure it out.  The key for these allergies is to try and help our buddies deal with the itch.  Cleaning the house regularly, especially where they hang out the most, can help. Appropriate bathing, with calming shampoos once to twice a week can also help.  Your vet may also be able to prescribe antihistamines or other medications to help with the itch and calm your dogs skin. Allergy injections, which can have a success rate of 70-80% in some dogs, are also a good thing to discuss with your veterinarian.

  • Another frustrating allergy to deal with can be from food. We may not be what we eat, but we may suffer from what we eat! This allergy is just what is sounds like, it most often comes from a specific type of protein in the food. Your pet may be allergic to a chicken protein or a beef protein or another type of protein in the feed. This can happen gradually. Even though your dog has been on their food for a long time without problems, that does not rule out a slow reacting food allergy.

    • What to look for:

      This is an allergy that may or may not cause itchiness. This reaction can look like the others with redness, irritation, loss of hair and may or may not itch.  The areas affected can be anywhere but often look like environmental allergies with areas like the paws, face, arms and legs, belly and ears affected. Food allergies can also look like gastrointestinal issues, such as diarrhea and vomiting.

    • What to do:

      Your vet may suggest a diet trial.  This includes a few months of eating ONLY a specific diet with hypo-allergenic or unique proteins.  During these trials our fur babies cannot have treats, table scraps or access to anything from the trash or otherwise.  If they improve from the trial after a few months, then that helps figure out the cause.

  • A less common type of allergy is contact allergies. Have you ever touched a plant and then later had welts, blisters, or a raised rash? That is very similar to what our furry buddies deal with. Contact allergies come from touching something irritating and within hours to weeks after, they have a skin reaction.

    • What to look for:

      This can look like bubbles with fluid, redness and rash, or general irritation.  It is most often on the parts of the body not protected by hair or fur.  So that is the bottom of the paws, muzzle or abdominal area.

    • What to do:

      These can be very irritating but typically go away after contact with the irritant is gone.  The key to helping with these is trying to think what could the dog have come in contact with and also regular weekly bathing to help remove irritants. A common irritant can be the kind of bowl your dog eats and drinks from. Instead of plastic bowls, try either metal or ceramic bowls.  Beyond this your vet may prescribe antihistamines or, occasionally, steroids to help remove the itch and calm the skin.

All of these allergies are frustrating to deal with but remember, our companions can’t deal with these on their own like we can. Knowing what to look for, when to go to the vet, and how to help our pets is the way to help them “scratch that itch” and feel comfortable as they share their lives with us! Using DIG Labs' rapid skin scan can help you monitor your pet’s skin while also receiving tips on what to do, anytime, anywhere.