You always have to pay attention to the eyes and head. The eyes are supposed to be shiny and the head upright. A drooped head and tail, as well as the wings in birds might be the first signs of certain diseases. Large-sized animals that are not feeling well tend to withdraw from the horde whenever there is enough room for him to do so. The general aspect of the fur must be shiny, attractive, clean, and there should not be bald spots.
Young animals are frisky and playful, except at mealtime or when they feel tired.
Abnormal movements different from the usual ones might indicate pain, which is often what happens in cases of limping or cramps. One of the most important aspects of the physical exam is the temperature, which can be measured by inserting a thermometer in the rectum. It's necessary to lower the mercury level around 1 degree below the normal temperature of the animal being examined. To make insertion easier, the thermometer should be lubricated with Vaseline, oil or even water. The insertion should never be done roughly to prevent the animal from getting startled and making sudden movements that might cause the thermometer to break.