Allergic Shock in Dogs

Allergic Shock in Dogs - Symptoms, Causes, Diagnosis, Treatment, Recovery, Management, Cost

What is Allergic Shock?

When an allergic reaction occurs, it can be relatively minor through severe, causing a failure of nearly all of the major organs of your dog’s body. Should your dog experience a severe, instant reaction, you will likely see significant symptoms of his gastrointestinal and respiratory systems. This type of severe reaction is considered allergic or anaphylactic shock.

Should your dog have an allergic reaction, it is the result of his immune system responding to a particular substance, which his body has viewed as dangerous or as an “intruder”. When this happens, histamines will be released in order to combat what is seen as a problem. While rare, a reaction can be so extreme that it leads to distress throughout your dog’s body. Typically, should this occur, it will be as a response to an allergen that has already caused a reaction in your dog. Allergic shock is life threatening if not treated. Fortunately, most dogs will recover as long as they are treated in a timely manner.

A severe, instant reaction to a substance that leads to a failure of most of a dog’s major organs, allergic shock will cause gastrointestinal and respiratory symptoms and requires emergency medical attention.

Symptoms of Allergic Shock in Dogs

In allergic shock, your dog’s liver will be the organ impacted most quickly, therefore severe digestive upset is often the first symptom you will observe. While dogs usually exhibit little or no swelling of their face and throat, you may see the following symptoms should they experience allergic shock:

  • Itching or redness
  • Sudden diarrhea and/or vomiting
  • Appearing to have a hard time breathing/noisy breathing
  • Drooling more than usual
  • Increased heart rate
  • Inability to control bowels
  • Seizures
  • Low pulse
  • Coma

Should you suspect that your dog is experiencing allergic shock you will want to seek immediate medical attention.


Allergic reactions come in several categories:

  • Localized reactions - These are minor and usually limited to a particular area that had contact with what triggered the reaction and  will usually develop less than half an hour after the exposure has occurred; symptoms include itchiness and inflammation in small areas
  • Systemic allergic reaction or allergic shock - These will affect major systems in the body of your dog and the reaction can develop right away or within a few hours; this will typically only occur when your dog has exposure to an allergen with which he has previously had contact 
  • Seasonal allergies - These will usually present as congestion or bronchitis and occur at a particular time or times of year
  • Chronic allergy - These are ongoing reactions to a particular allergen

Allergic shock is the most severe form of an allergic reaction. Your dog can experience more minor forms of an allergy; it is important to pay attention to these more minor allergies as with repeated exposure to the allergen your dog is reacting to, he could experience allergic shock when exposed to the particular allergen down the road. Less severe allergy symptoms to be on the look-out for include:

  • Hives
  • Swelling
  • Rash that itches or bumps under your dog’s skin
  • Congestion
  • Chronic bronchitis that includes a dry cough
  • Trouble breathing when exercising
  • Vomiting after eating a particular food or foods

Causes of Allergic Shock in Dogs

A variety of substances and cause allergic shock in dogs to include:

  • Food or chemicals that are used in the food
  • Medications
  • Vaccinations
  • Insect bites

In an allergy, your dog’s immune system will react excessively to something he ingests or is exposed to. Because his immune system views the particular allergen as an intruder, it will respond by releasing a histamine, which will cause the symptoms that occur in your dog.

Diagnosis of Allergic Shock in Dogs

Should you observe symptoms of allergic shock in your dog, you will want to seek immediate medical attention. It is important to note any substances that you have noticed have triggered a response in your dog in the past, so that you can share this with your veterinarian. In the case of allergic shock, treatment must occur right away in order for your dog to stabilize. This means that while your veterinarian is examining your dog and asking about the symptoms you have seen and previous reactions he has experienced, he will also work to stabilize him. Based on the physical examination, your veterinarian will be able to determine if your dog is experiencing allergic shock. 

When you dog is experiencing less severe and perhaps chronic allergies, it can be challenging to determine what is leading to the reaction. To make a determination, your veterinarian will seek to expose your dog to a small amount of numerous substances and see if there is a reaction.

Treatment of Allergic Shock in Dogs

Should it be determined that your dog is experiencing allergic shock, your veterinarian will treat him with adrenaline, usually administered through an injection. Antihistamines and hydrocortisone are also regularly administered. Depending on your dog’s condition, your veterinarian may consider intravenous fluids and additional oxygen. 

Should your dog experience a mild allergic reaction, whether or not longer term, antihistamines will often be recommended and should those not be effective, steroids will be considered.

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Recovery of Allergic Shock in Dogs

Treatment for allergic shock is typically very effective; the majority of dogs who are treated in time will recover without any long term impacts on their health. Some dogs will need to remain at the veterinary hospital for a few days to confirm that their systems have normalized.

It is a good idea to work with your veterinarian on steps to avoid a future episode. How this will occur will depend upon what was the cause of the reaction. Your veterinarian may consider prescribing an Epipen, which is a single dose of adrenaline that can be injected into your dog should he experience allergic shock in the future; this can control his symptoms and allow you time to obtain medical help.

Allergic Shock Questions and Advice from Veterinary Professionals






7 Years


1 found this helpful


1 found this helpful

My boxer, age 7, was stung by well over 50 bees, she was given unasyn and enrofloxacin, an antihistamine, among other meds. Got here at 5:30 pm and by midnight she was seizing...they pumped her full of seizure meds, however, she keeps jerking/ question is could this still be anaphylactic shock? They are claiming that she most likely has a brain tumor (which she shown no prior signs of). Before the first 24 hours was up they were trying to convince me to euthanize her. Any help would be appreciated.

April 1, 2018

1 Recommendations

Anaphylactic shock may recur (biphasic anaphylaxis) in some cases without any additional stimulus from an allergen, this is why we monitor animals for 72 hours after the initial reaction. Without examining Mia I cannot say whether there is a tumour or if this is another reaction from the initial reaction. Regards Dr Callum Turner DVM

April 1, 2018

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American Eskimo




11 Months


0 found this helpful


0 found this helpful

My pet has the following symptoms:
Shaking Panting
Shaking Panting Salivating
Shaking Panting Salivating...
My 11 month old American Eskimo I guess ate something and got very sick her diagnosis was GI shock (an extreme allergic reactions) it onset rapidly with in 45 minuets she was salivating, shaking, panting, not wanting to move around, not being able to stand up with out wobbling, squinting of eyes, ears where completely flattened back and for her breed ears are natural pointed straight up, and for a little while had Fecal Incontinence (she temporarily lost the ability to control her bowel movements) I work at a vet so I was concerned right away so I monitored her for about 10 minuets then brought her to the 24 hour vet where I work in that ten minuets tried to get her up and moving tried to get her to drink or eat her favorite snake that she never turns down and she did not want it she was 100% not acting like the same dog.

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