dog’s skin has always been itchy and every summer he has to be
treated. Recently, he underwent a lot of tests and I have been told
that he has flea allergy dermatitis. The problem is that I have
never seen a flea on him. Is this diagnosis correct?
Flea allergy dermatitis (FAD) is the
leading cause of itching in dogs. Fleas do not stay on the dog
except for when they are feeding. When they feed they inject a small
amount of saliva into the skin. This is the substance that dogs
become sensitive to and causes an intensely pruritic or itchy
response. Dogs with FAD don’t have to be infested with fleas to be
itchy. In fact, a single flea bite can cause itching for up to a
Are only certain dogs allergic to
FAD can affect any adult dog
although some breeds appear to be more prone than others.
How is flea
allergy dermatitis diagnosed?
Clinical signs often give us the
first clue that your pet may suffer from FAD. Itching and hair loss
in the region from the middle of the back to the tail base and the
rear legs is often associated with FAD. Additionally, we have
sophisticated skin and blood tests that will detect a specific flea
allergy in your pet.
What does treatment involve?
Since it is the injection of flea
saliva that causes the allergic response, it is important that to
prevent fleas from biting your dog. Strict flea control is
essential. Even though you have not seen fleas on the dog it is
important that you continue rigorous flea treatment and maintain
environmental control. Outdoor dogs pose a particular challenge.
There is a separate fact sheet that outlines flea control.
about desensitization? I understand that this is a newer treatment
Desensitization involves injecting
increasing doses of a flea antigen over a prolonged period of time.
These allergy injections may be continued for life. Desensitization
therapy is successful in approximately 50% of cases. We will discuss
the pros and cons of the various treatments for FAD with you during
What about steroid treatment?
Corticosteroids, “cortisone” or “steroids” are widely used to treat
FAD. They often bring about miraculous relief to the poor pruritic
patient. However, it should be noted that there are significant side
effects to steroid use. The long term use of corticosteroids can
ultimately result in more harm than good.