Dear Christopher Cat:  Milo, my 15-year-old indoor male cat, is constipated. Any suggestions?

Christopher Responds: Take Milo to see his veterinarian, who can determine the cause of his constipation and prescribe the appropriate treatment.

Constipation has many causes, particularly in elderly cats. A common cause is decreased motility of the large intestine, also called the colon.

As the muscles of the large intestine contract to move fecal material along, the colon absorbs water back into the body to help maintain normal hydration. This process transforms wet, slurry-like feces into the normal bowel movements you’re accustomed to seeing in the litter box.

But if the colon’s motility is slowed, the feces will sit there longer than normal, getting dryer and harder than usual. Treatment for this problem involves medication to improve colon motility.

Another reason for constipation in older cats is chronic kidney disease, which interferes with the kidneys’ ability to conserve water and maintain normal hydration. The large intestine takes over, absorbing more water from the feces, leaving them excessively dry and hard.

At-home administration of a sterile electrolyte solution beneath the skin helps with this problem.

Lack of exercise, obesity and conditions that cause pelvic pain, such as arthritis of the low back or an anal-rectal mass, also induce constipation.

Once your veterinarian determines the cause of Milo’s constipation, effective treatment can begin.