Causes
Ideally, cats should defecate at least once every other day. Constipation is a condition seen most commonly in mature, middle-aged cats, although it may occur at any age.
Factors associated with the development of constipation include:
• Hairballs, especially in longhaired cats.
• Ingestion of foreign bodies such as bones.
• Pelvic injuries resulting in a narrowed pelvic canal.
• Dehydration, possibly due to kidney disease or hyperthyroidism.
• Obesity and/or lack of exercise.
A much more serious cause is Megacolon, a term referring to a dilated and weak colon that causes severe constipation. In this condition, the weakened muscles of the colon fail to propel fecal matter out of the colon. This may be due to neurological impairment, problems with the muscles lining the colon, or both.
Symptoms
Affected cats usually strain unsuccessfully to defecate, and may cry in pain. Any feces passed are hard and dry. The cat may also show signs of lethargy, reluctance to eat, abdominal pain and distension, and vomiting.
Unless your cat is obese or tense, your veterinarian can often palpate or feel the accumulated fecal material in the colon.
Further tests may be needed in order to diagnose the cause of the constipation. These may include abdominal and pelvic x-rays to look for pelvic injuries, colonic strictures (a narrowing of the exit passage, resulting from a previous problem), or tumors.
Bloodwork and urine testing can also help diagnose underlying disease conditions that can contribute to constipation.
WARNING - A vet visit is highly suggested if a cat goes for more than 3-4 days without having a bowel movement. This can prove dangerous if not addressed.
Treatment
Medication
What I recommend is Enulose (Lactulose Solution). The bottle comes with a little syringe making it easy to dose. My cat Motor used to get constipated from having CKD, so now I give this to him once daily for maintenance. Since then, he gives me a perfect stool every day or two! FYI: You might want to adjust the dosage down a bit if your cat's stool starts to become too soft.
Another unintended (off-label) benefit of Enulose (Lactulose Solution) is that it acts as an ammonia detoxicant, which helps to remove ammonia from the bloodstream. This is yet another way to help cats with chronic kidney disease feel better, and can serve to prolong their lives.
Massage Therapy
A very simple way to help move feces through a cat's large intestine manually is by the use of massage. It's not a cure all, and is typically used in addition to other treatments. The large intestine is very near the top of a cat's body. Apply a "little" pressure starting from the middle of their body just below the spine and moving towards the rectum. Try to apply the pressure on both sides of their spine to help the feces to move.
Dietary Supplement
If the constipation recurs or becomes a long-term problem, dietary management or medications may be needed to prevent recurrence. A number of treatments are available to soften the feces and promote regular bowel movements. In mildly affected cats, high fiber supplements like Weruva's Pumpkin Puree, lubricating laxatives, or stool softeners may prevent recurrence. Again, I would recommend the Enulose (Lactulose Solution) listed above.
Initial treatment of a cat with constipation may involve administration of enemas and manual extraction of feces by a veterinarian. Removal of feces from the colon often requires an anesthetic or sedative. Intravenous fluid therapy is usually required to correct fluid imbalances and dehydration that worsen the constipation.
WARNING - MiraLAX is sometimes suggested by vets to help deal with constipation. And as many reviews suggest that it works to help relieve constipation in cats, I do not recommend this product as its been surrounded in controversy for quite a while. This due to the fact that the main ingredient in MiraLAX is Polyethylene Glycol (PEG), a petroleum-derivative compound that is made from ethylene glycol (ethane-1,2-diol), the main ingredient in antifreeze. In some studies, certain doses have been found to be toxic to the kidneys in both cats and humans.