Constipation is one of the most common reasons senior cats end up at the vet — and one of the most under-discussed. If your older cat is straining in the litter box, going less often, or crying out while trying to go, the short answer is: this is common with age, it’s usually manageable, and it’s worth taking seriously rather than waiting it out.
Why Constipation Gets More Common With Age
A few things stack up as cats get older, and they compound each other.
Kidneys work less efficiently. Chronic kidney disease is extremely common in cats over 10, and one of its first effects is that cats lose water through urine they’d otherwise keep. Less water in circulation means less water available to keep stool moving through the colon.
Arthritis makes the litter box physically harder to use. A cat with sore hips or a stiff spine may avoid squatting fully, hold on longer than they should, or skip trips to the box altogether — all of which give the colon more time to pull water out of the stool, making it harder and harder to pass.
The colon itself loses muscle tone with age, the same way most smooth muscle in the body does. Weaker peristalsis (the wave-like contractions that move stool along) means things move more slowly even when hydration and mobility aren’t the issue.
Reduced activity plays a role too — cats who sleep 18+ hours a day and move around less have slower gut motility in general.
None of this means constipation is “just aging” and not worth addressing. It’s a symptom with identifiable, often treatable causes — the job is figuring out which one (or combination) applies to your cat.
What Normal vs. Concerning Actually Looks Like
Most healthy cats defecate once or twice a day. A day or two of lighter output during a diet change or stressful event isn’t automatically alarming. What crosses into “call the vet” territory:
- No bowel movement for 48 hours or more
- Visible straining with little or no result
- Crying or vocalizing in the litter box
- Small, hard, dry stools (versus normal formed stools)
- Repeated trips to the box with nothing produced
- Lethargy, reduced appetite, or vomiting alongside any of the above
That last combination matters — a cat who’s constipated and not eating and vomiting needs to be seen the same day, not “in a few days if it doesn’t improve.” That pattern can signal obstipation (severe, entrenched constipation) or megacolon, both of which require veterinary intervention rather than home management.
What You Can Do at Home for Mild Cases
For a cat who’s straining occasionally but otherwise eating, drinking, and acting normal, a few adjustments genuinely help:
Increase water intake. This is the single highest-leverage change. Switching from dry to wet food adds meaningful moisture — a cup of dry kibble has roughly 10% moisture, while wet food runs 70-80%. A cat water fountain can also increase how much cats drink, since many cats are instinctively drawn to moving water.
Check litter box accessibility. If your cat has arthritis or other mobility issues, a box with low sides they don’t have to climb into makes a real difference. Multiple boxes on different floors of the house also reduce how far a stiff senior cat has to travel.
Talk to your vet about fiber. Both increasing and, counterintuitively, sometimes changing the type of fiber in the diet can help — this isn’t a one-size-fits-all fix, and pumpkin (a popular home remedy) has genuinely modest evidence behind it at best. It’s a reasonable low-risk thing to try, but it’s not a substitute for addressing an underlying cause like dehydration or kidney disease.
Never give a human laxative without veterinary guidance. Products like Miralax are sometimes used in cats under a vet’s direction with specific dosing, but self-dosing is risky — cats are not small dogs, and dosing that’s safe for a person can cause problems for a cat.
When It’s Not a Home-Management Situation
Your vet will typically start with a physical exam and often bloodwork to check kidney values, thyroid function, and calcium levels, since all three affect gut motility. If constipation is recurrent or severe, they may recommend X-rays to check for megacolon — a condition where the colon becomes chronically stretched and loses its ability to contract effectively. Once megacolon sets in, management usually shifts from occasional fiber and hydration tweaks to prescription motility medication, and in advanced cases, surgery to remove the affected section of colon.
This is why vets tend to treat repeat constipation episodes as a pattern worth investigating rather than a string of unrelated incidents. Catching kidney disease or early motility problems before they progress to megacolon is a much easier fix than managing megacolon itself.
When to See a Vet
Book a visit (don’t wait) if you see:
- No stool for 48+ hours
- Straining with crying or obvious distress
- Straining combined with any vomiting or not eating
- Blood in or around the stool
- A third episode of constipation within a few months — recurrence is the signal that something underlying needs to be identified, not just managed symptom by symptom
Constipation in a senior cat is rarely an emergency in isolation, but it’s also not something to quietly manage indefinitely without your vet ruling out kidney disease or early megacolon. A cat who strains occasionally and otherwise seems fine can often be helped with hydration and litter box changes. A cat who’s straining, not eating, and lethargic needs to be seen that day.
The Association of Feline Practitioners recommends twice-yearly wellness exams for cats over 10, in part because subtle motility and kidney changes are much easier to catch — and treat — early than after they’ve become entrenched.