Symptoms To Watch For In Your Dog: Fever (Pyrexia)

Fever is one of the things that you notice only when you're paying close attention. 

It can be recognized by signs such as decreased appetite, lethargy, weakness, fast breathing or panting. These symptoms are not very specific, though, and can be caused by other things as well.

A dog's normal temperature falls between 99.5 and 102.5 Fahrenheit.

A temperature of 103.5° F or higher is considered a fever.

The range between 102.5 and 103.5 is somewhat ambiguous. A dog who has been running around on a hot day may temporarily have a temperature in this range and be perfectly normal. On the other hand, a dog with a temperature of 103.2 who has just been lying around probably has a fever.

What's the difference between fever and hyperthermia? 

They both refer to abnormally high body temperature. Fever, however, is a specific form of hyperthermia where the temperature rises as part of immune function. This is different from hyperthermia caused by inadequate means of heat dissipation or problem with thermoregulation.

The purpose of a fever is to enhance the functioning of the immune system and to create an inhospitable environment for invading organisms.

Elevated body temperature helps certain types of immune cells to work better. What does that mean? While extremely high fever is dangerous, mild fever is functional and assists the healing process. So the trick is to know when to allow the fever to do its thing and when to intervene. When temperatures reach 106 F, serious and fatal complications can occur.

After her horrible drug-induced hyperthermia, it's always been very hard for me not to panic when Jasmine's temperature rose even a little bit. And, unfortunately, increased body temperature was part of her episodes.

For me, the do-something point was 103.5° F.

I'd never use a fever-reducing drug, though. I just cooled with wet towels. If your dog's temperature hits about 104.5° F it's time to talk to a vet immediately.

The most common cause of fever is an infection.

Other things that can be behind your dog's fever are immune-mediated diseases, tumors, metabolic or endocrine disease, inflammatory conditions, certain drugs, and toxins.

Vaccination can cause a low-grade fever for about 24 to 48 hours after administration. Stress, agitation, exercise, and high ambient temperatures can also increase your dog's body temperature.

The important thing is not to get fixated on the fever—unless it’s extremely high—but to determine and address the underlying cause.

Related articles:
Veterinarians Answer: 10 Main Symptoms To Watch For In Your Dog 
Symptoms: Recognition, Acknowledgement, And Denial
Symptoms To Watch For In Your Dog: Excessive Panting
Symptoms To Watch For In Your Dog: Excessive Drinking
Symptoms To Watch For In Your Dog: Bad Odor 
Symptoms to Watch For In Your Dog: Excessive Drooling  
What Can Your Dog's Gums And Tongue Tell You? 
Symptoms To Watch For In Your Dog: Coughing 
Symptoms To Watch For In Your Dog: Excessive Head Shaking  
Symptoms To Watch For In Your Dog: What Is That Limp? 
Symptoms To Watch For In Your Dog: Nose Bleeds (Epistaxis)
Symptoms To Watch For In Your Dog: Unexplained Weight Loss
Symptoms To Watch For In Your Dog: Loss Of Appetite  
Symptoms To Watch For In Your Dog: Lethargy 
Whats In The Urine? (Part I: What You Can Notice On Your Own)
What's In The Urine? (Part II: Urinalysis)
A Tale of Many Tails—and What Came Out From Underneath Stories from My Diary-rrhea (part I)
Acute Small Intestinal Diarrhea
Acute Large Intestinal Diarrhea (Acute Colitis)
Chronic Large Intestinal Diarrhea
Chronic Small Intestinal Diarrhea
Don't Panic, Don't Panic: Know What Your Job Is 

Further reading:
Why Is My Dog Running A Fever? 
Fever in Dogs

Do you know what your dog is telling you about their health?

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Symptoms to Watch for in Your Dog now available in paperback and Kindle. Each chapter includes notes on when it is an emergency.

Symptoms to Watch for in Your Dog is an award-winning guide to help you better understand what your dog is telling you about their health and how to best advocate for them. 

Learn how to see and how to think about changes in your dog’s appearance, habits, and behavior. Some signs that might not trigger your concern can be important indicators that your dog needs to see a veterinarian right away. Other symptoms, while hard to miss, such as diarrhea, vomiting, or limping, are easy to spot but can have a laundry list of potential causes, some of them serious or even life-threatening. 

Symptoms to Watch for in Your Dog is a dog health advocacy guide 101. It covers a variety of common symptoms, including when each of them might be an emergency. 

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