Cat Constipation: Symptoms, Causes and UK Vet Advice

Signs of constipation in cats

PDSA lists straining in the litter tray, hard dry or small stools, reduced frequency of defecation, and sometimes small amounts of liquid stool (which can be confused with diarrhoea) as common signs. A constipated cat may visit the tray frequently without producing much, cry while straining, or become reluctant to use the tray altogether.

Other signs can include reduced appetite, mild abdominal discomfort, a hunched posture or vomiting. Because straining to urinate and straining to defecate look similar from a distance, it is important to check whether your cat is passing urine normally — a male cat straining to urinate is an emergency.

• Hard, dry, small or infrequent stools.
• Repeated unproductive visits to the litter tray.
• Crying, restlessness or discomfort while trying to pass stool.
• Liquid stool or faecal smearing, which can indicate impaction with overflow.
• Reduced appetite, vomiting or lethargy alongside reduced bowel movements.

Common causes of constipation

Dehydration is one of the most common contributing factors. Cats on a dry-only diet and cats that drink little water are more prone to hard, dry stools. Hairballs, especially in long-haired breeds or during shedding season, can contribute to impaction. PDSA also lists obesity, lack of exercise, pain from arthritis that makes squatting difficult, and ingestion of foreign material such as string or litter as possible causes.

Medical causes include kidney disease (which causes dehydration), megacolon (a condition where the colon loses its ability to contract effectively), neurological disease, pelvic injuries that narrow the pelvic canal, and certain medications. Older cats are more commonly affected, and the risk increases with age.

• Dehydration or a dry-food-only diet.
• Hairballs, especially in long-haired breeds such as Persians and Maine Coons.
• Obesity and low activity levels.
• Arthritis or pain that makes the squatting posture difficult, particularly in senior cats.
• Kidney disease causing chronic dehydration.
• Megacolon, foreign material, pelvic narrowing or neurological disease.

What you can safely do at home

For a mildly constipated cat that is otherwise bright, eating and drinking, encourage water intake by providing fresh water in several bowls, considering a water fountain, and offering wet food if your vet agrees. Cats Protection suggests that grooming your cat regularly, especially long-haired breeds, reduces the amount of hair swallowed during self-grooming.

Do not give human laxatives, enemas, mineral oil or milk. Human products can be unsafe or ineffective in cats, and milk can cause diarrhoea rather than relieving constipation. If your cat is mildly constipated for more than a day or two, call your vet for advice rather than waiting for it to resolve on its own.

How a UK vet diagnoses constipation

Your vet will ask about diet, water intake, litter tray habits, frequency and appearance of stools, appetite, vomiting and any medications. The examination includes palpating the abdomen to feel for retained stool in the colon, checking hydration, body condition and the pelvis.

In some cases your vet may recommend an x-ray to assess the extent of constipation, look for a foreign body, or check for megacolon. Blood tests may be suggested if an underlying cause such as kidney disease is suspected. The treatment plan depends on the cause and severity rather than constipation alone.

Treatment options

Mild constipation may be managed with dietary change, increased water intake and a vet-recommended stool softener or lubricant. Your vet may prescribe a specific laxative or gastrointestinal diet tailored to cats. More severe cases may require an enema performed under sedation or anaesthetic at the practice, or manual removal of impacted stool.

For chronic or recurrent constipation, particularly if megacolon is present, long-term management may include prescription high-fibre or gastrointestinal diets, regular laxative medication, and monitoring. In some cases surgery is considered. International Cat Care notes that early intervention and consistent management can help prevent progression to megacolon.

Breed-specific and age-related notes

Long-haired breeds such as Persians, Maine Coons and Ragdolls are more prone to hair-related constipation, particularly during seasonal moulting. Regular grooming and hairball remedies recommended by your vet can help. Older cats are at higher risk because of reduced activity, arthritis pain, kidney disease and decreased intestinal motility.

British Shorthairs are not uniquely predisposed to constipation, but their tendency to be less active and potentially overweight can contribute. Maintaining a healthy weight, encouraging activity and providing a balanced diet with adequate moisture are practical steps for all breeds.