In fact, the colon can easily store several weeks worth of stool so if only a few days have passed it may be worthwhile to wait a little longer. Simple constipation can be caused by any number of reasons. This is not an uncommon cause for constipation and often treatment for the excessive grooming is helpful. Some animals, especially dogs, get in the habit of eating gravel, stones, dirt, bones, or plants. This does not usually indicate a dietary deficiency as many owners suspect, though we do not have a good explaination for this unusual dietary behavior.
Stools produced can be sharp or painful to pass, often leading to straining and discomfort.
An important potential cause of constipation to check for is an electrolyte imbalance, especially in an older pet. This may be the only noticeable sign of an important metabolic problem such as kidney failure . If the constipation has been an recurring problem then this kind of labwork database becomes especially important. An internal obstruction may be causing the problem. For example, animals hit by cars often suffer a fractured pelvis.