Constipation in Cats

Constipation in cats can be a frustrating disease for owners and veterinarians alike, not to mention a serious cause of discomfort for our feline friends. This diagnosis is especially common and can vary in severity. We’ll dive into a deeper discussion of constipation in cats.

What Is Constipation in Cats?

Cats can develop constipation, obstipation, or megacolon. These terms are defined below:

Constipation: an abnormal accumulation of stool within the colon leading to difficult or nonproductive attempts to defecate. This results in smaller or absent bowel movements.

Obstipation: this is a severe state of constipation leading to the complete inability to produce a bowel movement.

Megacolon: a weak and dilated colon leading to severe constipation – typically occurring secondary to chronic constipation or obstipation.

Causes of Cat Constipation

Constipation is a condition most often seen in middle-aged (~6 years of age) cats with male cats having a higher predisposition. Domestic Shorthair cats are most commonly affected, but there has also been a high prevalence in Domestic Longhair cats and Siamese. The majority of these cases (>60%) have no known cause and are considered idiopathic. Otherwise, common causes include:

• Pelvic canal stenosis – or narrowing of the pelvic canal
• Orthopedic disease or injuries
• Neurological injuries/conditions
• Congenital spinal cord deformities
• Complications after surgery for colopexy
• Colonic cancers
• Foreign body ingestion
• Obesity
• Dehydration

Signs of Constipation in Cats

Cats with any spectrum of constipation may present with similar clinical signs. Most often cats will demonstrate anorexia, vomiting, and straining to defecate at home. There will either be decreased or no stool production in the litter box. The feces produced are often small and dry. Cats may appear painful and lethargic. Owners may also notice abdominal distension and discomfort.

Diagnosis of Constipation in Cats

Constipation in cats is diagnosed through a combination of physical examination findings, medical history, and diagnostic imaging. A physical examination will reveal firm fecal material within the gastrointestinal tract and discomfort on abdominal palpation. Diagnostic imaging, such as an x-ray, is utilized to confirm the presence of constipation as well as to assess its severity. X-rays can also be used to diagnose predisposing conditions such as osteoarthritis, congenital abnormalities of the spine or pelvis, lumbosacral disease, tumors, etc.

Bloodwork should also be performed to assess for concurrent diseases and the presence of dehydration. As many of these cats are middle-aged to older, it is not uncommon for them to have additional comorbidities that can cause dehydration, such as chronic kidney disease, hyperthyroidism, or diabetes.

Constipation in Cats Treatment

Treating constipation in cats requires a dynamic approach and often requires the utilization of several different interventions.

Short-Term Management:

Fluid therapy

Rehydration is extremely important as many constipated cats are dehydrated. For minor dehydration, subcutaneous fluids may be sufficient. With moderate to severe dehydration, hospitalization for intravenous fluid therapy is recommended. Occasionally, rehydration is enough to alleviate fecal impaction.

Enemas

Enemas are another mainstay treatment for constipation in cats. These work by rehydrating feces to allow ease of passage. Enemas should never be performed at home or with over-the-counter enema solutions because this can lead to toxicity or rectal perforation.

Deobstipation

Cats with moderate to severe obstipation that are not responding to fluid therapy and enemas may require deobstipation – the manual removal of feces. Cats are placed under anesthesia. Water or saline is introduced into the colon to help break up the feces. Digital manipulation or instruments are used to manually remove the feces with care given not to perforate the colon.

Long-Term Management:

To improve constipation it is important to address any underlying concurrent medical issues that may complicate treatment. Once these are addressed, management will consist of diet changes, laxatives, promotility medications, and probiotic therapy.

Diet

Diet change is the first line of long-term management of constipation in cats. There are many food options available, but the most efficacious diets tend to include those with higher amounts of highly digestible fiber. It is best to find a diet that is palatable to the cat to increase compliance.

Laxatives

There are several laxatives available for the treatment of constipation in cats. Common laxatives include lactulose, bisacodyl, and dioctyl sodium sulfosuccinate. Laxatives containing PEG 2250 – like MiraLAX – are more effective and generally well tolerated. These laxatives work by binding water to keep it within the gastrointestinal tract. The dosing of laxatives is highly variable and can be adjusted until the cat achieves the desired fecal consistency. Adjustments should be made slowly; laxatives often take more than three days to see positive effects.

Promotility Agents

Promotility agents work by speeding the movement of ingesta through the gastrointestinal tract and stimulating colonic contractions. Cisapride is the most used promotility agent.

Probiotics

Cats with chronic constipation may benefit from probiotics. An experimental study showed improvements on histopathology and endoscopy in cats that were treated with a probiotic.

Surgery

In end-stage cases of constipation and megacolon, subtotal colectomy is considered an option. This surgery entails removing portions of the colon (depending on the severity and extent of the disease) and then forming a new connection between the colon and the small intestine. Cats generally have a good prognosis after surgery but may have diarrhea for weeks to months after the procedure. This surgery is considered a salvage procedure and is only recommended for cats with constipation or megacolon that are not responding to medical management.

Constipation in Cats Requires Lifelong Management

Constipation can be a frustrating condition in cats that can present in a spectrum of severities. Treatment is separated into short and long-term stages with the short-term treatment consisting of fluid therapy, enemas, and removing the fecal impaction. Long-term therapy is geared toward treating underlying conditions, dietary alterations, and the addition of laxatives, promotility agents, and/or probiotics. Many cats will have a good prognosis and respond well to medical management. Others may require surgical intervention but can still have a good long-term prognosis.

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