People who have constipated dogs should follow their vets' recommendations, according to the American Society for the Prevention of Cruelty to Animals. Generally, vets may prescribe medication, recommend a laxative or the addition of fiber to the diet, such as canned pumpkin or wheat bran.
The vet may also recommend that the dog exercise more. An enema may be needed, but should be administered at a veterinary office, according to the ASPCA.
DogTime.com explains that exercise increases the blood flow in the colon and massages internal organs. A vet may also recommend milk of magnesium, powdered psyllium seed, mineral oil, aloe ferox, and natural supplements that include folic acid and other aids to resolve constipation.