Allergic Reactions in Dogs and Cats

Allergic reactions are a fairly common ailment in dogs.

Cats are much less likely to suffer from allergic reactions than dogs.

Dogs may manifest allergic reactions by:

     Swollen, non-painful face

     Hives that are visible through the coat.  Hives in dogs vary in size but appear similar to welts or raised areas ranging in size from ½ a dime to over 2 inches in diameter. 

     Severe itchiness


     Bloody vomiting (hematemesis)


     Bloody diarrhea (hematochezia)

     Shock/collapse/lethargy/respiratory distress/cardiovascular collapse/airway obstruction

Causes of allergies include but are not limited to:

     Bee sting

     Wasp sting

     Spider envenomation

     Unknown environmental allergen

     Dietary allergen

The treatment of allergies varies by the severity of symptoms.  Common questions we receive at our hospital is ”How much Benadryl can be given to our dog?” The internet has many sources of information.  Here is one:

Another great resource is:

Please don’t forget, your veterinarian is also a good source of information.  If you are concerned that your pet is experiencing an allergic reaction, please call your veterinarian for recommendations and advice.