allergies in dogs

Allergies in Dogs — The Basics



Allergies in dogs are the reason for more visits to a veterinary clinic than any other health issue for pets.

Pets can be exposed to allergies in three different ways:

  • contact allergies
  • dietary allergies
  • inhaled allergies
  • and then there are the frustrations of atopy and flea allergy dermatitis.  More on these below.



    Dogs in the wrong place at the wrong time

    Contact Allergies in Dogs


    Anyone who has ever wandered through poison oak can sympathize with the irritation that dogs with contact allergies go through.

    CAUSE:  Your dog’s allergy to plant particles or chemicals in their environment.  Most common are grass allergies, but sensitivity to detergents, cleaners, and wool rugs are not uncommon.


    • redness, sometimes swelling and hives
    • worst on underside of paws, armpits, belly, and groin– areas of little hair


    • Find someplace else to walk — sometimes have to avoid grass completely
    • After outside exercise, foot soaks and cool water sponge baths to dislodge allergens
    • If your dog’s feet are most affected, use soothing disinfectant foot soaks after they come in from a walk.  Buy some chlorhexidine from your vet, or some white vinegar from the store.  Mix the chlorhexidine 1:10 with water or the vinegar 1:2 with water, and soak your pet’s affected feet for 2-3 minutes after outside exposure.  This mix will a) kill bacteria, b) soothe the itch, and c) taste horrible to your dog… all good things.
    • Aloe vera/oatmeal shampoos with cool water rinse.  Leave the suds in place for 10 minutes before rinsing.
    • If short haired dog, you can use soothing topical hydrocortisone or aloe vera ointments in irritated areas.
    • Testing, natural treatments, and oral medications as covered below.

    when a dog’s best friend turns against them

    Allergies in Dogs — Dietary Allergies


    Your dog can be allergic to ANYTHING they eat — their kibbles or canned food, their treats, the snacks you give them, or your neighbor’s cat food.  This is NOT a reflection of dietary quality — you can be feeding the best diet in the world but your dog may become allergic to it

    CAUSE: The most common sources of allergies for dogs are the MEATS and GRAINS within the food and treats, but every once in a while you’ll find dogs who are allergic to veggies, too.  Right, Daisy McE?


    • Recurrent ear irritation in BOTH ears
    • facial and neck itch, sometimes hives.  If your pet’s itch is worst above the collarline, consider dietary allergies.
    • occasional facial swelling or hives
    • GI symptoms: vomiting, diarrhea, and the dreaded dog farts.
    • May see itch/irritation on sides or belly but generally NOT over hips.


    • Avoiding the diet component your dog is allergic to.  Simple, but hard.
    • If your dog is a roamer, keep them inside– they could be allergic to something a quarter mile away.
    • Prescription drugs are less effective for dietary allergies than other types.
    • If you do not use drugs to speed things along, a diet change will take 6-8 WEEKS to show improvement, so PATIENCE.


    DIETARY ALTERNATIVES:  in general, the farther down this list you go the better your odds of success.

    • Look at current ingredients, find retail diet with different grains and meats
    • Retail Vegetarian or Vegan diets
    • Retail Rabbit diets (available online)
    • Prescription single ingredient diets:  Rabbit, Kangaroo, Alligator
    • Prescription hydrolyzed diets:  Hills Z/D, etc.
    • Homecooked meals
    Dog Allergies -- Inhaled allergies

    The most common in humans, the least common in dogs.

    Allergies in Dogs — Inhaled Allergies

    CAUSE:  Your pet is inhaling a plant pollen or dust particle they are allergic to.


    • “Hay fever” — runny eyes, irritated eyes, sneezing, clear nasal discharge
    • Rarely can see facial swelling or hives


    • Move to a different neighborhood… or state
    • Traditional medical therapy, below.





    is your pet itching over the hips?

    Allergies in Dogs — Flea Allergies

    While every pet owner rightfully fears flea infestations, FLEA ALLERGIES can be a much more frustrating problem to deal with.

    CAUSE:  Your pet is allergic to flea SALIVA, so that the bite of just one flea — just one — can cause weeks of itching.  No preventive can fully eliminate this, since most of them require that a flea bites your pet to kill them.

    SYMPTOMS:  Severe itch/chewing/baldness over the hips.  Because your pet is chewing so much, secondary skin infections are almost always present.

    TREATMENT:  Massive flea control efforts.

    • Bravecto offers 3 months of protection, and is available as flavored pill or topical.  Note: If you have an allergic pet, beware the meat flavorings of many medications.   Here is a 15% off coupon for Bravecto.
    • Treat all pets in the family
    • Premise flea control — indoor areas of carpet, under furniture;  outdoor grass areas, wood mulch, under trees/bushes
    • If your pet wanders, keep them home to avoid flea contact down the street.
    • General treatment of itch and secondary infections, as mentioned below.
    Allergies in dogs -- flea allergies
    Allergies in dogs -- Atopy

    A big problem with a new solution

    Allergies in Dogs — Atopy

    CAUSE: A genetic defect in the protective waxy layer of your pet’s skin allows allergens that would normally “bounce off” your pet to penetrate into the skin, causing severe symptoms

    SYMPTOMS:  severe itch around the ears, the feet, and the flanks of affected pets.  


    • Restore the waxy layer of the skin– prescription shampoos and rinses
    • CYTOPOINT injections actually block the messenger molecules causing the itch within your pet’s body.  A medical miracle, and a great investment for the atopic pet!!
    • General treatment of itch and secondary infections, mentioned below.


    is it right for you?

    Allergies in Dogs — Allergy Testing

    Allergy testing and desensitization has come a long way in the last decade. 

    The old days of having to use needles for both painful allergy testing and the desensitization are gone.  Nowadays we test your pet’s blood for allergies and can then prescribe ORAL vaccines to help desensitize them against those allergens.

    The advantage?  About 70% of dogs can successfully be desensitized against the allergen creating their itch.  In the case of dietary allergies, you are given a clear list of “safe” ingredients and a clear list of ingredients to avoid.

    The disadvantage?  Primarily cost.  Where I live, you can expect about a $450 bill for the testing, and the desensitizing serums are an additional  charge.

    On balance, if you have a YOUNG dog who is affected by allergies, allergy testing may be the best investment you’ll ever make.  For older pets, you just have to do the math… but your pet would really appreciate it.

    Dog allergies-- Allergy testing in dogs

    Holistic treatments will help any itchy dog.

    Allergies in Dogs– Holistic Treatments



    • Aloe vera, lavender, or calendula oils on areas of irritated skin.  Note that these may sting if the skin has been damaged by your pet’s chewing or scratching.
    • Aloe Vera/oatmeal shampoos– leave the suds on your pet for 10 minutes before rinsing well with cool water.
    • To treat mild generalized skin infections, you can use a bath consisting of 1 part white vinegar to 4 parts cool water.  Leave in contact for 10 minutes, and do not rinse it off.

    ANTIHISTAMINE THERAPY:  Antihistamines are less effective in pets than they are in humans, because the immune systems of our pets don’t use nearly as much histamine as messenger molecules… so ANTI- histamines don’t work as well.  Having said that, they will help some pets, and they are very safe.  Here is what you need to know:

    • Benadryl will help 10-15% of pets, and can be given at a dose of 1 mg per lb body weight twice daily.
    • Zyrtec will help 20-30% of pets, and can be given at a dose of 1 mg per 2 lbs body weight once daily.
    • Yes, these are both high doses when compared to humans.  They are also correct.

    is it right for you?

    Allergies in Dogs — Drug Therapy

    If your pet is severely affected by allergies, prescription drugs will be a huge benefit to them.  

    In general, there are four classes of drugs that will help an allergic pet:

    • Effective flea medications
    • Anti-itch oral drugs
    • Antibiotics to control the secondary infection that your pet’s scratching and chewing have caused
    • Topical ointments and shampoos

    We’re going to set flea meds aside for right now.  Here’s a brief summary of the most effective drugs to help your pet’s allergies…

    ANTI-ITCH MEDICATIONS.  These suppress your pet’s immune system, because a hyperactive immune system is  the source of their problem.  Note that there are disadvantage to using any immune suppressant on a chronic basis, but the short term benefits may far outweigh the long term risks.

    • PREDNISONE — the old standby.  Cheap and effective, but lots of side effects (thirst, panting, hunger, etc)
    • APOQUEL — the new kid on the block– more expensive, but excellent at eliminating itch without notable side effects.
    • CYCLOSPORINE (ATOPICA) — the most potent immune suppressant. A little pricey.

    ANTIBIOTICS:  Needed in a majority of cases due to the damage your pet does to their skin by scratching and chewing.  

    Note that in severe or recurrent infections, your veterinarian may recommend culture and sensitivity testing to tell exactly what bacteria are present and exactly what the best drug to kill them might be.

    • CEPHALEXIN — cheap, good for mild to moderate infections.  Given orally 2-3x daily.
    • SIMPLICEF– just like cephalexin, but only needs to be given once daily and is thus more expensive.
    • CLAVAMOX–  for deeper or more severe infections.  Given orally twice daily. Can create vomiting/diarrhea.
    • CONVENIA — The new kid on the block, Convenia is a potent antibiotic related to cephalexin that will last for 14 days with one injection.  What this means is it is VERY CONVENIENT for you, and also a little pricey.


    • Antibiotic only — a retail example would be Neo-Sporin
    • Steroid only– a retail example would be hydrocortisone ointment.
    • Antibiotic/Antifungal/Steroid — very effective “shotgun” therapy.
    • Soothing or numbing compounds containing pramoxine.
    Dog allergies -- The Drugs your pet needs

      Like to Help Your Pet Live Longer?   Let’s Get Started. 

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    Kevin Toman, DVM