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Posted on 07-26-2016

Allergic Reactions in Dogs

Pets can have reactions to their environment just like their human caretakers. Allergic reactions are individual inflammatory responses against specific allergens (proteins) entering the body.  These can be caused by insect bites or stings, spider bites, vaccines, pollens, dust and even food.  A reaction may be just redness and swelling at the site or might include hives (tiny bumps on the body), facial swelling, itchiness, redness of the skin, or agitation/restlessness.  These types of reactions are often treated with Antihistamines (like Benadryl or diphenhydramine) or Corticosteroids (like dexamethasone or prednisone).

dog with an allergy

Although rare, more serious reactions called anaphylactic reactions, can occur may result in shock and even death.  These reactions are abnormal reactions where the body's immune system over-reacts to the foreign protein or substance resulting in the reaction.  Anaphylactic reactions typically begin within 15 minutes of exposure to the allergen. Most cases of anaphylaxis are thought to have a hereditary or familial basis.

What is Anaphylactic Reaction/Shock?

Anaphylactic reactions are sudden, widespread, and severe allergic reactions.  If untreated these reactions can lead to shock (low blood pressure) and systemic failure involving most all of the major organs of the body and are potentially life threatening. 

Causes of Anaphylaxis in Dogs

Substances which can trigger anaphylaxis shock in dogs are fairly similar to those which cause the same condition in humans.  Some of the common triggers are listed below:

  • Food or chemicals
  • Drugs or medications
  • Injections including vaccinations
  • Insect bites or stings
  • Atopy or allergic skin reactions are common in about 10% of dogs. Some breeds including Dalmatians and Terriers are more susceptible.

Like humans, dogs can develop long term allergies to dust, mold, pollen, or even dander. These allergies do not usually lead to anaphylactic shock, although they could indicate a predisposition to allergic reactions. 

Symptoms of Anaphylaxis in Dogs

To keep your pet safe,  know what warning signs to look for when it comes to an allergic reactions.  When dealing with anaphylactic shock in dogs common symptoms include:

  • Vomiting
  • Collapse/severe depression
  • Diarrhea, often becomes bloody
  • Fast heart rate
  • Weak pulse
  • Itching or redness at the site of contact
  • Difficult noisy breathing
  • Seizures
  • Signs of shock

Unlike humans, there may be little or no swelling of the face or throat. Seek immediate medical attention if your dog exhibits any of the above symptoms, especially if the response is triggered by a potential allergen.  Less-serious responses are also possible but these symptoms can still be important since allergic shock may develop later or with repeated exposure to the allergen

Diagnosis of Anaphylaxis in Dogs

Our veterinarians can usually diagnose allergic shock based on the symptoms. Knowing the triggering substance and your dog’s medical history can also help. Treatment will need to happen immediately in order to save your dog’s life, so handle the situation as an emergency.  Call either our north or south Emergency Animal Hospital as soon as you notice any symptoms of anaphylaxis in your dog.   

Treatment of Anaphylaxis in Dogs

If your dog is experiencing anaphylactic shock, our veterinarians will administer emergency drugs such as epinephrine. Patients will need intravenous fluids to counteract the drop in blood pressure. Organ systems such as the liver and kidneys can be affected.  Patients may also experience internal bleeding which will require blood products such as plasma to correct. Your dog may need to stay in the hospital for several days to ensure that all systems have returned to normal.

Recovery of Anaphylaxis in Dogs

Prompt treatment is needed to ensure that your pet will have the best possible chance for survival. Steps may need to be taken to avoid a reoccurrence of the incident however including diet, medication and lifestyle changes. New allergies can develop quickly, so it’s a good idea to watch your dog’s reactions very closely anytime he is bitten by an insect, tries a different food or a new medication.

If you think your pet may be experiencing anaphylaxis, call one of our hospitals and our staff will be glad to help you.  

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