Allergy Season!

 Allergy season is now upon us!  Did you know your pet dog and cat can suffer from allergies?  Allergies in our pets are unfortunately becoming more and more common.  Many of us humans are familiar with the runny, red eyes and sneezing that our seasonal allergies bring upon us.  Dogs and cats can develop respiratory, eye and nose symptoms due to their allergies, but skin and ear problems are a much more common form of allergies in our pets.  Below we will discuss the most common allergies we see in our veterinary hospital patients.  Do you recognize symptoms in your pet below?

A flea. Don't worry - they're not really this big!

  

Flea Allergies

 

Obviously, any pet that develops a flea infestation is going to be itchy.  (In veterinary terminology, we refer to "itchiness" with the medical term "pruritus.")  But some dogs and cats actually develop an allergy to the proteins present in flea saliva.  This causes their body to overreact with an intense inflammatory response, causing more severe itching, hairloss, and the development of bacterial and/or yeast skin infections.  The areas of the body affected by flea allergies are usually quite distinctive.  The back, flanks, rump, tail, and hindquarters are usually the worst areas affected.  Some patients will lose all of the hair in these regions, and develop extremely red, scabbed skin from the secondary infections.

One flea bite can make a patient with flea allergies itch for THREE WEEKS!  This is why your veterinarian may diagnose "flea allergy dermatitis" (or FAD for short!) in your pet without the presence of a single flea on physical examination.

Treating flea allergies requires an approach that includes flea treatment/prevention, treatment of any skin infection with appropriate antibiotics or antifungals, and medications to help decrease the inflammation and resultant itching (antihistamines and corticosteroids such as prednisone are common choices).  Animals with flea allergies must receive a monthly flea preventative every 3 to 4 weeks, the environment must be treated for fleas, and all of the other pets in the house must also receive a monthly flea preventative product.   

  

Food Allergies

Dogs and cats with allergies to certain food ingredients will often manifest with skin problems.  We often see hairloss, red skin and skin infections on the face, lower portions of the legs, and belly in dogs and cats.  Cats especially like to develop skin problems on their face with food allergies.  Recurrent ear infections are also often related to food allergies in pets.  Symptoms of food allergies differ from some other types of allergies, as the pet will usually have allergy problems all year round, as opposed to symptoms resolving during a certain time of year.

Hill's Prescription Diets for Allergies

It can be difficult to pinpoint the causative agent of food allergies in a particular pet.  The most common ingredients causing allergic responses in dogs are (in no particular order) beef, chicken, pork, soy, corn, and wheat.  The most common ingredients that affect cats are similar, but also include fish.  Of course, these are the most common ingredients found in commercial pet food.  This does NOT mean that commercial pet foods are bad!  Not every pet has a food allergy, after all.  But for those that do, most commercial pet foods will cause a reaction.

Food allergies are unique in pet allergies, as the medications we use to treat itching in pets (corticosteroids in particular) are not quite as effective if the itch is due to food allergies as opposed to flea allergies or environmental allergies.

If your vet suspects food allergies in your pet, he or she will likely recommend a special diet trial.  Many options are available.  In a food allergic pet, finding the right food makes all the difference in symptoms and quality of life!

Environmental Allergies

Dogs and cats can be allergic to just about anything in their environment.  Environmental allergies, also called "atopy" or "atopic dermatitis" can be broken down into two categories - seasonal allergies and nonseasonal allergies.  These allergens are breathed into the respiratory system, and cause skin manifestations of allergies.  Contact skin allergies can also occur.

Ragweed Pollen

Seasonal allergies are currently upon us!  These are the pets that begin to be itchy and develop skin problems when the seasons change, and then symptoms resolve when the particular season is over.  Fall is particularly bad for seasonal allergies.  Changes in pollens from changing plant life are often the culprit.  Treating resultant skin infections and antihistamines/corticosteroids are often used during the pet's bad season to treat this condition.

Nonseasonal allergies cause similar symptoms to seasonal allergies, except the symptoms last all year.  Nonseasonal allergies can develop due to environmental components such as house dust mites, molds, fibers (like cotton) and other irritants constantly present in the environment.  These are very frustrating to treat, as the pet seems to be in a constant state of irritation.

In cases of severe seasonal and nonseasonal atopy, referral to a veterinary dermatology specialist may be necessary for skin testing.  With skin testing, the offending allergens can be identified, and an allergy serum can be developed specifically designed for each individual patient.  This serum is administered as an injection at home on a decreasing basis, to sensitize the pet to the allergen, and subsequently decrease the inflammatory response.  Other treatment options are available as well, and are best discussed on an individual basis with your pets doctor.

As you can see, allergies cause an awful lot of skin problemsin pets.  A complicating factor is that many patients have more than one type of skin allergy.  However, not all skin problems are due to allergies!  Keep in mind that your veterinarian may recommend certain tests, such as skin scrapings, ear cytologies, cultures, or bloodwork if he or she suspects another cause of skin problems.