Pet Allergies

Why am I so Itchy???

Is your dog or cat asking themselves this question? As we enter spring and summer, I’m sure a lot
of you would say “yes, absolutely!” Allergies are frustrating because we can only control the signs, not
cure the condition. Even a pet that has a well-controlled allergy can experience flare-ups from time to time.
However, it’s not all bad news. New treatments are becoming available to us and we can keep most pets
comfortable throughout their allergy season.
There are 3 main types of pet allergies. They are flea bite allergy, atopy (inhalant allergy) and
food allergy. It is difficult sometimes to determine exactly which allergy your pet has based on physical
signs, meaning the 3 types can look alike. Flea allergies are the easiest to diagnose just by finding fleas or
flea dirt on physical exam. Inhalant or food allergies are a little more difficult to distinguish. Dogs with
any type of allergies may show the following signs:
Chewing the feet
Rubbing the face on the carpet or furniture
Scratching the body
Recurrent ear infections
Hair loss
Mutilated skin
Cats are also generally itchy, have hair loss in certain patterns and may have miliary dermatitis (small scabs
all over the skin).
Allergies usually start to develop between 1 to 3 years of age but can start later. As the pet ages, it can
develop new allergies and the response to allergens becomes more severe.

To diagnose allergies, we may need to rule out other causes of itchy or irritated skin such as
sarcoptic or demodectic mange, yeast or bacterial skin infections, intestinal parasites or ringworm. As
mentioned before, if fleas are found, we usually have our diagnosis. If there are no fleas and we can rule
out the other conditions, we start to consider the other 2 types of allergy.
We may think your pet has a food allergy if the pet’s symptoms are year-round (not seasonal), the
allergy doesn’t respond to treatment with antihistamines or steroids, or if their red and itchy areas are
located around the eyes and mouth, armpits or area around the anus. These signs can also overlap with
inhalant allergies. For this reason, we may suggest a food trial. A food trial consists of feeding the pet a
food they have never eaten before. Examples of these diets are venison and potato or duck and pea. The
diet is the only thing the pet eats for 12 weeks. This means no treats and no table scraps. If the itching
goes away but returns after going back on the original diet, the diagnosis of food allergy is confirmed.

Just a quick word about food intolerance. A pet with food allergies shows the characteristic signs
of itching and skin problems. A pet with a food intolerance may have diarrhea and vomiting after eating
the certain food but does not have itchy skin or other skin problems. Fortunately, both food intolerance and
food allergies can be eliminated with a diet free of the offending agent.

Pets with inhalant allergies are allergic to airborne particles. Common allergens are trees, pollens,
molds, grasses, fabrics, house dust and dust mites. These allergies are seasonal at first but can progress to
year-round. If the allergies are mild and are not year-round, we may choose to control them by various
combinations of medications and topicals. For instance:
Antihistamines (Benadryl, Atarax): Not very effective when used alone in some dogs and are
more effective in cats. Several different antihistamines may have to be used before an effective one is
found. Minimal side effects.
Fatty Acids: Work in the skin to help reduce the amount and effects of histamine that is released
in response to allergies. Most pets need to take fatty acids daily for several weeks before improvement is
seen. Work best when combined with other treatments such as antihistamines. Minimal side effects.
Topical Treatments: Topical sprays containing a steroid can provide relief to local areas.
Medicated shampoos and crème rinses offer short-term relief, but they do help wash allergens off the hair
coat and calm the skin. We may recommend once or twice weekly baths with these products in the overall
treatment plan.
Steroids: At our clinic, we try to use these with caution and are reserved as one of the last lines of
treatment when all else fails. They definitely relieve itching and inflammation and sometimes appear as a
miracle cure. However, there are serious side effects to using these drugs long-term such as increased risk
of infections, diabetes mellitus and liver problems. The short term side effects can also be difficult for the
pet as well as the owner. They are increased thirst and urination, panting, increased appetite (weight gain),
depression or hyperactivity. We usually use steroids for brief periods to combat severely itchy skin, and
then try to use the other medications for the rest of the time.
Cyclosporine: This is one of the newest drugs approved for the treatment of inhalant allergies in
dogs. Cyclosporine blocks the release of specific chemicals from white blood cells that cause inflammation
in dogs that are allergic. It seems to be very effective with improvement of signs within 4 weeks. It is
safer than the long-term use of steroids with minimal side effects such as occasional vomiting and diarrhea.
The down side of this medication is its cost, especially for larger dogs.
If your pet’s allergies are severe, last longer than 4 to 6 months and don’t respond to medications,
it’s time for allergy testing. Allergy testing determines what the pet is exactly allergic to. This can be done
with a simple blood test in our office or by referral to a veterinary dermatologist for intradermal skin
testing. Once we know the allergens your pet is sensitive to, the pet must avoid those allergens ideally.
Obviously, this can be impossible in some cases. In that case, immunotherapy may be the best option. A
series of commercially prepared injections containing the altered antigens are injected weekly or monthly at
home by the owner. The pet then becomes desensitized to the offending allergens. Treatment is timeconsuming
and requires a dedicated owner, but success is as high as 80%.
If your dog has an ear infection that keeps coming back or spends his free time licking his feet, he probably
has allergies! Please contact our office with your questions.
Dr. Christy Collignon