Canine Fever
Does your dog have a fever? Below is a list

of common symptoms. Your dog does not necessarily have to have all of them:
Signs and symptoms of fever:
Lethargy, depressed mood
Decreased appetite
Vomiting
Shivering
Coughing
Rapid heart rate
Dehydration
Nasal discharge
Temperature 103 or higher
Do you know how to take your dog’s temperature? Accurately assessing your dog’s temperature is accomplished using a digital rectal thermometer. You should have one in the first-aid kit you keep for your animals. Lubricate the tip with petroleum jelly or baby oil and gently insert it about one inch into your dog’s anus and then remove it as soon as you get a reading.
The best way to treat a fever of 103 or greater in your dog is to bring the dog to a veterinarian. A fever of 104 is considered very high.
If you believe your dog only has a fever or you cannot immediately get to a veterinarian consider the following treatments:
Wrap your dog is cool towel. If the dog won’t tolerate the towel, either sponge with cool water or apply cool, damp cloths and dry off.
Areas to apply cool cloths – ears, groin, flank, “arm pits” and paws. Always towel dry.
Give your dog cool water to drink. If the dog won’t drink, then syringe fluids into the dog. Consider unflavored pediatric electrolyte solution. If none on hand, make your own with Karo syrup, salt and cool water until you can buy some.
If fever remains stubbornly high after 24 hours (higher than 103), bring your dog to a veterinarian.
What causes fever in dogs?
Infection – bacterial, fungal or viral
Vaccinations
Toxins – if suspected call the Pet Poison Hotline 1-855-764-7661
Ingestion of human medications
Tick-borne diseases
Fever of unknown origin – because you cannot determine the cause
Sources: https://www.akc.org/expert-advice/health/dog-fever-and-temperature