Take the dog’s temperature with a rectal thermometer (most accurate)
Normal rectal temperature for dogs: about 100.5–102.5°F (38.1–39.2°C)
Fever is typically: 103°F (39.4°C) or higher
Very high fever: 104°F (40°C) or higher
Check for lethargy or unusual weakness
Look for reduced appetite
Watch for shivering, trembling, or chills
Notice fast breathing or panting not typical for the dog
Feel hot ears, nose, or skin (helpful but not reliable without a thermometer)
Look for vomiting or diarrhea
Watch for coughing, labored breathing, or signs of pain
Check gum color: pale, very red, or unusually dry gums can be a concern
Monitor hydration: dry gums, sticky saliva, or sunken eyes can indicate illness
If the dog has a fever plus lethargy, trouble breathing, persistent vomiting/diarrhea, severe weakness, seizure, or collapse, seek urgent veterinary care
If the temperature is 103°F (39.4°C) or higher and does not improve quickly, contact a veterinarian promptly
If the temperature is 104°F (40°C) or higher, seek emergency veterinary care immediately
If the dog may have heat exposure (hot environment, heavy exercise, car exposure), treat as urgent—cool the environment and contact a veterinarian right away