Constipation in Dogs: Causes and Treatments

Constipation means absent, infrequent, or difficult defecation. Most healthy dogs have one or two stools a day. This varies with the individual and the diet. A day or even two without stools is not a cause for concern, if the stools remain normal in size and pass without difficulty. But when feces are retained in the colon for two or three days, they become dry and hard, and require forceful straining to pass.

Note that straining also occurs in dogs with colitis, obstructed bladder, and anorectal obstructions.It is important to be sure the dog is not suffering from one of these other problems before treating him for constipation. Colitis, in particular, is often confused with constipation. Remember that a dog with colitis will pass many small stools that contain mucus and/or blood.

Causes of Constipation

Many middle-aged and older dogs are prone to constipation. A common predisposing cause is failure to drink enough water. With mild dehydration, water is withdrawn from the colon, which dehydrates the feces.

Ingesting foreign materials such as bone chips, hair, grass, cellulose, cloth, paper, and other substances is a well-recognized cause of acute and chronic constipation. The indigestible material mixes with feces to form rocklike masses in the colon.

Many drugs commonly used in dogs cause constipation as a secondary side effect. Discuss this possible correlation with your veterinarian. Hypothyroidism is an occasional cause of chronic constipation.

The urge to defecate can also be voluntarily overridden. Dogs develop such inhibitions during housetraining. When left alone in the house for long periods, they often override the urge to defecate. Dogs may also be reluctant to empty their bowels when hospitalized, boarded, or taken on a trip.

Dogs with constipation of recent onset should be examined by a veterinarian. Other reasons to seek veterinary consultation are painful defecation, straining during defecation, and passing blood or mucus.

Treating Constipation

Eliminate or control predisposing causes. Be sure to provide access to clean, fresh water at all times. Constipation associated with ingesting foreign materials such as bone chips can be corrected by eliminating the source and giving dog biscuits to chew on instead. Older dogs with reduced bowel activity can be helped by soaking the kibble with equal parts of water and letting the mixture stand for 20 minutes.

Dogs who voluntarily retain their stool can be helped by providing frequent opportunities for the dog to eliminate. Take the dog outside several times a day, preferably to an area where he is accustomed to going. A mild laxative may be needed when the dog is traveling.