Cat Constipation: Complete Guide + Vet Q&A

Cat constipation is one of those symptoms that cat owners prefer to treat at home. 

The availability of laxatives and enemas over the counter is a temporary solution and can cause more harm than good if administered outside of the vet’s office. 

Another issue that harms your cat’s health is the administration of human medication which is toxic to cats. 

The underlying causes of constipation in cats can be serious medical issues and therefore you should take your cat for a checkup before attempting any home treatments. 

In this guide, I will cover symptoms, causes, and treatment options for cat constipation and hopefully better prepare you for the vet visit.

Let’s scratch this issue.

What Is Cat Constipation?

Constipation in cats is the abnormal accumulation of feces in the colon, resulting in difficult bowel movements. This condition can lead to reduced frequency or absence of defecation. When a cat is constipated, the feces become hard and dry due to water absorption in the colon, making it even more challenging to pass the stool.

Cat constipation can be painful and some cats may pass small liquid feces that contain blood. 

While mild cases of constipation can be managed with simple home treatments, severe or persistent constipation may require medical intervention.

vet explains cat constipation

Symptoms of Cat Constipation

  • Little to no fecal production while attempting to poop: Cats with constipation may strain in the litter box but produce little to no feces or have difficulty passing stool.
  • Frequent visits to the litter box: Cats with constipation may make more frequent trips to the litter box in an attempt to relieve themselves.
  • Vomiting: Constipated cats may vomit due to the discomfort and gastrointestinal distress caused by the condition.
  • Dry, hard stools
  • Decreased appetite
  • Abdominal pain: They may show signs of discomfort such as restlessness, vocalization, or sensitivity when their abdomen is touched.
  • Straining to defecate and vocalization: Cats with constipation often strain and show visible signs of effort while attempting to pass stool. They may assume a hunched posture and have difficulty eliminating waste. Vocalization that sounds like crying is an indication of pain. 
  • Swollen belly
  • Refusing to lie down
  • Fever or low body temperature
  • Loss of  interest in interacting with family
  • Hiding
  • Drinking more or less water and peeing more

Causes of Cat Constipation


Dehydration is one of the most common causes of cat constipation. When a cat doesn’t drink enough water, their body tries to conserve water by absorbing more of it from the colon, which can result in hard, dry stool that is difficult to pass. 

Electrolyte Disturbance

Electrolytes play a crucial role in maintaining proper fluid balance and normal muscle function, including the muscles of the gastrointestinal tract. 

When there is an imbalance or disruption in electrolyte levels, it can affect the movement and coordination of the muscles involved in peristalsis, the wave-like contractions that propel fecal matter through the intestines.

Electrolyte disturbances can arise from underlying diseases, medications, or dietary imbalances. 

For example, a condition called hypophosphatemia, which is characterized by low phosphorus levels in the blood, can lead to electrolyte disturbances and affect the contractility of smooth muscles in the colon, resulting in reduced motility and transit time, which can contribute to constipation.

Certain medications, such as opiates or anticholinergics, which are known to affect gastrointestinal motility, can cause constipation as a side effect.

Lack of exercise

Lack of exercise can also contribute to constipation, as physical activity helps to stimulate the digestive system and promote bowel movements.

Poor diet

Cats that consume a diet lacking in fiber may have difficulty passing stool, as fiber helps to add bulk to the stool and promotes regular bowel movements. Cats that consume a diet consisting solely of dry food may be at greater risk of constipation, as dry food doesn’t contain as much moisture as wet food.


Cats that are anxious or stressed may experience changes in their digestive system, which can lead to constipation. 


When cats experience pain, particularly in the abdominal or pelvic region, they may instinctively suppress the urge to defecate to avoid exacerbating the pain. This suppression of the natural urge to eliminate can lead to constipation.

Pain can also cause increased muscle tension, including in the muscles involved in bowel movements. This increased tension can lead to constriction of the intestines, making it more difficult for stool to pass through.

Litter box aversion 

When a cat avoids the litter box, it can result in behavioral and health issues, including constipation. Here’s how the two are connected:

Stress and Anxiety: Changes in the environment, such as moving to a new home, the introduction of new pets, or disruptions in the household, can cause cats to develop aversions to their litter boxes. When cats are stressed, they may hold their stool, leading to constipation.

Reduced Frequency of Elimination: Cats with litter box aversion tend to hold their urine and feces for longer periods because they avoid using the litter box. This can disrupt their natural elimination routine and lead to constipation. Infrequent bowel movements and prolonged retention of feces can cause the stool to become hard and difficult to pass.

Decreased Water Intake: Cats that are avoiding the litter box may also avoid drinking water, especially if they associate their litter box with negative experiences. Insufficient water intake can contribute to dehydration, which can result in dry and compacted stools, further exacerbating constipation.

Inadequate Exercise: Cats that are anxious or stressed due to litter box aversion may also be less active and engage in reduced physical exercise. Lack of exercise can slow down their digestive system, making it harder for them to pass stools effectively and leading to constipation.

Medical Conditions: In some cases, litter box aversion may be a sign of an underlying medical condition that can also contribute to constipation. For example, cats with urinary tract infections, gastrointestinal obstructions, or painful defecation due to anal gland issues may associate the litter box with discomfort or pain, leading to aversion and constipation.

Underlying Health Issues 

If constipation is a new symptom, talk to your vet about running some tests. Early detection of health issues such as kidney disease, diabetes, cancer, hypothyroidism, etc. gives your cat a chance of full recovery. 

If constipation is followed by already diagnosed health issues, talk to your vet about the best course of treatment. 

Pelvic region injury or tumors 

Pelvic fractures are a common type of injury in cats and can result from trauma, such as being hit by a car or falling from a significant height. 

When the pelvic region is fractured, it can lead to the narrowing of the pelvic canal, which is the passage through which feces normally pass during defecation. 

Tumors can develop in bones, muscles, or organs in the pelvic region. Depending on the size and location of the tumor, it can exert pressure on the surrounding structures, including the colon or rectum. This pressure can disrupt the normal peristaltic movement of the intestines and hinder the smooth elimination of feces, leading to constipation.

Impaired Nerve Function: Pelvic injuries or tumors can damage the nerves that control the muscles of the pelvic region, including those responsible for bowel movements. 

The disruption of nerve signals can affect the coordination and strength of the muscles involved in defecation, leading to a decreased ability to pass feces normally and resulting in constipation.

Megacolon: In some cases, chronic constipation resulting from pelvic injuries or tumors can lead to a condition called megacolon. Megacolon is characterized by the dilation and stretching of the colon, which becomes weak and loses its ability to propel feces effectively. As a result, feces accumulate in the colon, further exacerbating the constipation

Obstruction of the gastrointestinal (GI) tract

When a cat experiences a GI tract obstruction, it means that there is a blockage in either the small intestine or the large intestine (colon), which prevents the normal passage of food and liquid through the digestive system. 

This obstruction can be caused by fibrous bands of tissue (adhesions), hernias, foreign objects( ex: bones), tumors, etc.

As a result, the stools become harder and drier, making them difficult to pass. The cat may strain during bowel movements, and the stool may appear small and pellet-like.

Cats with GI tract obstruction may exhibit other symptoms such as: 

  • abdominal pain
  • vomiting
  • loss of appetite 
  • lethargy 

Note that GI tract obstruction is a serious condition that requires immediate veterinary attention and intervention to alleviate the blockage and restore normal gastrointestinal function.

Inflammatory Bowel Disease (IBD)

Inflammatory Bowel Disease is a condition in which a cat’s gastrointestinal (GI) tract becomes chronically irritated and inflamed. 

While the exact cause of IBD is unknown, it is believed to arise from a complex abnormal interaction between the immune system, diet, bacterial populations in the intestines, and other environmental factors.

When a cat develops IBD, inflammatory cells infiltrate the walls of the GI tract, leading to the thickening of the intestinal lining. 

This thickening can affect the normal movement of the intestines and disrupt the muscle contractions responsible for propelling waste material through the digestive system. Consequently, the cat may experience difficulties in moving feces along the GI tract, resulting in constipation.

While constipation can be associated with IBD in some cases, it is not a typical symptom of the disease. More commonly, cats with IBD may experience diarrhea, vomiting, weight loss, and poor appetite. However, the effects of IBD can vary among individuals, and constipation can occur as a result of inflammation and motility issues in some cases.

Anal Gland Issues

When functioning normally, the anal glands release a small amount of this liquid during defecation, which helps with marking territory. However, several issues can arise with the anal glands, causing discomfort and potentially leading to constipation in cats:

Impaction: Impaction occurs when the duct or tube used to empty the anal sac becomes clogged. This can happen due to the thickening of the glandular secretion, poor anal muscle tone, or chronically soft feces. When the anal sac is impacted, it can lead to pain and difficulty during defecation, resulting in constipation.

Infection: Anal gland infections can occur when bacteria build up in the anal sacs. Infections can cause inflammation and swelling, leading to discomfort and potential obstruction of the anal passage. This obstruction can contribute to constipation in cats.

Abscess: In some cases, anal gland infections can progress to abscess formation. An abscess is a localized collection of pus, which can be painful and may interfere with normal bowel movements.

Signs of anal gland issues in cats may include: 

  • scooting along the floor
  • straining to defecate
  • scratching or biting around the anal area
  • licking the anus excessively
  • presence of discharge from the anal glands

Perianal disease in cats 

Refers to disorders or conditions that affect the anus and surrounding areas. It can include anal sac disease, perianal fistulas, perianal tumors, and rectal tears. Here is a breakdown of some of the common perianal diseases in cats:

Anal Sac Disease: Cats have anal sacs or glands located on each side of the anus. These glands can become impacted, infected, abscessed, or cancerous. Signs of anal sac disease may include scooting, licking, or biting at the anal area, and discomfort while sitting.

Perianal Fistulas: Perianal fistulas are a disorder characterized by inflammation and irritation of the anus, rectum, and perineum regions in cats. This condition can be progressive and painful for the cat. Symptoms may include diarrhea, anorexia, weight loss, constipation, ulcerations in the perianal region, and fecal incontinence.

Perianal Tumors: Perianal tumors are abnormal growths that can occur in the perianal region of cats. These tumors may be benign or malignant and can cause discomfort, difficulty defecating, or bleeding. Diagnosis and treatment of perianal tumors require veterinary evaluation.

Rectal Tears: Rectal tears in cats can be caused by foreign bodies, bite wounds, or trauma from palpation. Clinical signs often include tenesmus (straining to defecate) and hemorrhage. Treatment depends on the severity of the tear, with partial tears potentially managed conservatively and full-thickness tears requiring surgical repair.

Neuromuscular Diseases 

Certain neuromuscular disorders can affect the normal functioning of the muscles involved in the digestive process, including the muscles of the colon and rectum. 

These disorders can disrupt the coordinated contractions necessary for moving fecal matter through the digestive tract, leading to constipation. 

While the specific mechanisms can vary, these disorders often result in weakened or impaired muscle function.

Specific neuromuscular diseases that can lead to constipation in cats include:

Idiopathic Constipation: In many cases, the exact cause of constipation in cats is unknown and is referred to as idiopathic constipation. This condition may be associated with abnormalities in the neuromuscular control of the colon, causing impaired movement and motility of the intestinal muscles.

Peripheral Nerve Disorders: Disorders of the peripheral nerves, which transmit signals between the central nervous system and the muscles, can affect the normal coordination of muscle contractions in the digestive tract.

 Cats with peripheral nerve disorders may experience weakness or paralysis of the muscles involved in defecation, leading to constipation. 

For example, idiopathic facial paralysis can cause weakness or paralysis of facial muscles, including the muscles involved in chewing and swallowing, which can indirectly impact the GI tract.

Food allergies

Food allergies occur when a cat’s immune system overreacts to a specific food substance it has been exposed to previously. 

While food allergies in cats most commonly affect the skin, causing itching and scratching, they can also affect the gastrointestinal tract, leading to symptoms like diarrhea and vomiting.

Food allergies trigger an inflammatory response in the gastrointestinal tract. This inflammation can lead to digestive issues, including constipation. The exact mechanism behind how food allergies cause constipation in cats is not fully understood, but it is believed that the inflammation interferes with the normal motility of the intestines, causing a delay in the movement of fecal matter.

Treatment for Constipation in Cats

vet explains cat constipation treatment

Your vet will evaluate and run tests to determine the cause of constipation.

Enema and fluids are often administered to provide relief, however, focusing on the underlying cause is the priority.

Depending on the cause, treatment may include medications prescribed by the vet to surgery or general treatment of the illness. 

How to help a constipated cat at home?

Our instinct is to immediately do something to help our cats, especially when they are in pain.
While there are cat laxatives available over the counter, it is recommended to first take your cat for a checkup.

Constipation can be a symptom of serious health issues, so administering medication without vet guidance can worsen the symptoms. 

After the vet consultation, there are things you can do at home that will help your cat recover. 

  1. Include wet foods: you can either purchase wet canned foods or add water to dry food. You can cook a home meal, just make sure you are including different food groups with a priority on protein and fiber. This will help with hydration, especially if your cat is not drinking enough water. 
  2. Try different food: if the source of constipation is a food allergy. Try a hypoallergenic diet to see if symptoms subside. Fiber and probiotics could also help, however, these should be suggested by your vet. 
  3. Increase movement: Help your cat move more by playing, adding new toys, cat trees, etc.
  4. Add new or multiple litter boxes: if your cat has an aversion to the litter box due to its association with pain, try to replace it with a new box or just add one more to a different location. Make sure litter boxes are clean and placed in quiet places. 
  5. Try different types of cat litter: Cats have preferences when it comes to litter. If their discomfort is related to the litter box, a change of litter substrate can help stimulate curiosity and a change of smell could build a new relationship with the litter box.
  6. Reduce stress: Keep a consistent schedule in feeding and playtime. Make daily activities predictable to help your cat regain a sense of safety. 

Vet Q&A

Q: How to treat a constipated senior cat?

A: Constipation affects senior cats more than young ones. Treatment for constipation is the same for cats of any age. Follow your vet’s advice, including wet foods, help your cat move more, and make sure your cat is using a litter box. 

Q: How does a cat act when constipated?

A: Your cat may visit the litter box multiple times without successful defecation. Cats can also hide, look lethargic and vocalize when in pain. The stomach will also be swollen. 

Q: How long can a cat go without pooping?

A: If your cat hasn’t pooped for 48h take it to the wet. In some cases such as procedures or surgery, cats will be constipated but your vet will prescribe medication as a treatment of the original issues. Normal bowel movement for cats is at least once a day