Puppies

• Puppies have slightly lower temperatures than adult dogs. Newborns have temperatures of 94 to 97 F, or 34.4 to 36.1 C. By the time they are one month old, this will rise to 100 F or 37.7 C.
  
  

Pregnant Dog

• Dog Owner's Home Veterinary Handbook notes that a female dog's body temperature will suddenly drop 12 to 18 hours before she is about to give birth.
  
  

Fever

• A dog has a fever when its temperature is above 102.5 F or 39.2 C. This means that the dog is fighting an infection.
  
  

New Medicines

• When giving a dog a new kind of medication, the dog may come down with a fever. Should this happen, please contact your vet right away and note if there are any other symptoms like vomiting, diarrhea, problems breathing or loss of coordination.
  
  

Taking Temperature

• Coat a rectal thermometer in petroleum jelly or KY Jelly and gently insert into the dog's rectum with a twisting motion. Insert one to three inches (depending on the size of the dog) and leave in place for three minutes.