Constipation and Obstipation in Cats
- Constipation is a condition in which a cat passes feces less often or in smaller amounts than normal.
- Obstipation occurs when severe constipation makes defecation impossible or nearly impossible.
- Signs include infrequent or no defecation, straining to defecate, hard and dry feces, vomiting, or loss of appetite.
- There are numerous causes for these conditions, such as blockages from hairballs or other foreign materials, litterbox issues, decreased water intake or dehydration, lack of exercise, drug side effects, tumors or trauma, or a medical condition known as megacolon.
- To diagnose the condition, your veterinarian may gently press your cat’s abdomen to feel the intestines, but a radiograph (x-ray) may also be necessary.
- Treatment may include fluid therapy, stool softeners, dietary fiber, laxatives, motility modifiers, and enemas.
- In severe cases, surgery may be necessary.
What Is the Difference Between Constipation and Obstipation?
Constipation is a condition in which cats pass feces less often or in smaller amounts than normal. Feces are often hard and dry, which may cause cats to strain or have difficulty passing feces.
While constipation may occur periodically, obstipation is a more persistent and severe form of constipation, in which defecation is impossible or nearly impossible.
What Are the Signs of These Conditions?
Cats with constipation or obstipation may exhibit the following signs:
- Infrequent or no defecation
- Straining to defecate
- Hard, dry feces
- Defecating outside the litterbox
- Small quantities of feces
- Small amount of liquid stool with mucus or blood
- Lack of appetite
Male cats with a blocked urinary tract may also strain in the litterbox, and owners may mistake this for constipation. A blocked urinary tract is a medical emergency. If your cat is straining in the litterbox and there is no evidence of urine (or only a small amount of urine), contact your veterinarian immediately!
What Causes Constipation and Obstipation?
There are many potential causes of these conditions, including:
- Blockages from hairballs or other foreign materials
- Reluctance to use the litterbox because of stress, a change in litter, a full/dirty box, or painful urination
- Lack of exercise
- Decreased water intake
- Dehydration, often caused by kidney disease
- Nerve damage
- Arthritis, making it painful to squat
- Some drugs, including anesthetics
In some cats, a condition called megacolon contributes to constipation and obstipation. Megacolon is characterized by a decreased ability of the colon to move fecal material through in the normal way. Fecal material accumulates in the colon, resulting in constipation. Researchers believe that megacolon is caused by a problem with contraction of the muscles in the colon. It has also been suggested that severe prolonged retention of feces (as with constipation or obstipation) can stretch and damage the muscles of the colon, causing megacolon to develop. However, the cause of megacolon is undetermined in most cases.
How Are These Conditions Diagnosed?
Your veterinarian may be able to gently press his or her hands on your cat’s abdomen and feel the feces backed up in the intestines. However, in overweight cats, abdominal fat can limit your veterinarian’s ability to feel fecal material in your cat’s intestines. In these cases, a radiograph (x-ray) may be necessary to assess the problem. In the case of obstipation or megacolon, the colon will be greatly stretched beyond its normal size.
Occasionally, an endoscopic exam may be necessary. Anesthesia is required for this procedure, which involves inserting a tube containing a small camera into the rectum. This enables the veterinarian to look inside the rectum and colon for abnormalities such as narrowing of the colon or tumors that may prevent feces from passing.
Your veterinarian may also recommend blood work to look for underlying diseases that may cause dehydration leading to constipation.
How Are These Conditions Treated?
Treatment varies depending on the degree of constipation and the amount of discomfort your pet is experiencing. If constipation is mild, your veterinarian may supplement your pet’s diet with fiber, such as canned pumpkin, bran, or psyllium. Other medications, such as stool softeners, laxatives, and motility modifiers, may help as well. Some stool softeners and laxatives intended for humans are not safe for cats, so never give your cat a human medication unless instructed to do so by your veterinarian.
If an underlying condition, such as kidney disease, may be causing dehydration and constipation, treating the problem and rehydrating the cat with fluid therapy can help.
For more severe forms of constipation, enemas may be necessary, or the cat may need to be anesthetized for manual removal of feces.
In cases of megacolon, the diameter of the colon can sometimes be stretched so far that the muscles of the digestive tract are permanently damaged. When this happens, surgical removal of the affected portions of the colon may be necessary.