You are more familiar with your dog than anyone else and you should watch it carefully for subtle signs of illness that another person or even a veterinarian may miss. Dogs can’t talk so they rely on you recognizing the signs that they are not doing well.
General signs of illness include a lack of appetite or decreased activity. If your dog skips a meal once, it may not be a sign for concern. But eating poorly or skipping two or more meals may indicate something is not right.
More specific signs include vomiting and diarrhea, urinating more (or less) frequently, coughing and sneezing, or unusual discharge from body openings such as eyes, ears, nose, vulva, or prepuce. Illness can also show up as a loss of hair or itchy areas.
Problems with the musculoskeletal system are often seen as stiffness or lameness. Pay attention, especially with older dogs, to how they sit down and get up. If the action is accompanied by squealing or crying, there may be something really wrong.
If your dog shows any of these signs for a day or more, contacting your veterinarian is a good idea. The veterinarian may give you further instructions or advise on a treatment protocol if the symptoms are clear and point to an illness that is easily diagnosed. Anything more complex requires a trip to the clinic.
Taking the body temperature when you notice signs of illness is the best and the fastest way to confirm your worries. You should have a dedicated thermometer for your dogs. Best way to take temperature is to gently insert the thermometer into the rectum through the anal opening. Always use a clean thermometer rubbed with a bit of petroleum jelly. Normal body temperature for dogs ranges between 38oC to 39.2oC. There can be a small variation for particular individuals under specific circumstances. All this information can be very help if reported to your vet when you call.