You may first notice the problem as several soft piles in the litter box over a few days, then realize your cat’s diarrhea has continued for an entire week. At that point, call your veterinarian today rather than continuing home treatment alone. A week is long enough for dehydration, weight loss, or an underlying problem to become a concern, even when your cat is still eating and acting fairly normal. Ask whether the clinic wants you to bring a fresh stool sample, and keep your cat indoors if possible so you can watch the litter box closely.
When a cat has diarrhea for a week
Diarrhea means stool that is loose, watery, unformed, or much softer than usual. Some cats have one brief episode after stealing food or experiencing a sudden diet change, but diarrhea lasting seven days needs veterinary guidance because the cause is not always obvious at home.
A veterinarian may ask about diet changes, treats, new medications, parasite prevention, stress at home, outdoor access, vomiting, appetite, drinking, and litter-box habits. They may recommend an exam and testing based on your cat’s age, overall condition, and stool appearance. A photo of unusual stool can also be useful if collecting a sample is not practical.
When to seek urgent veterinary care
Call an emergency veterinary service now if your cat is weak, collapses, has trouble standing, seems severely painful, or cannot keep water down. These signs need prompt attention. Kittens, senior cats, pregnant cats, and cats with ongoing health conditions can become unwell faster than a healthy adult cat.
In practice, a bright adult cat that is drinking and has loose stool may be able to wait for a same-day regular appointment, while a cat that is listless, vomiting repeatedly, or showing blood should be treated as more urgent. If you weigh your cat regularly, a loss of around 5% of body weight over a short period is also worth reporting; for a 10-pound cat, that is about half a pound.
| What you see | What to do |
|---|---|
| Diarrhea for seven days, but cat is alert and drinking | Call your regular veterinarian the same day for advice and an appointment. |
| Blood in stool, black tar-like stool, repeated vomiting, or refusal to eat | Seek urgent veterinary advice today. These signs can accompany more serious illness. |
| Weakness, collapse, severe lethargy, a swollen painful belly, or inability to drink | Contact an emergency veterinary clinic immediately. |
| Very young kitten with diarrhea, even for a short time | Call a veterinarian promptly. Young kittens can dehydrate quickly. |
Fresh red blood can appear after irritation in the lower bowel, while black, sticky stool may indicate digested blood higher in the digestive tract. Neither is something to ignore. Tell the clinic about the color, amount, and whether your cat strains or cries in the box.
Also act quickly if your cat has dry or tacky gums, sunken-looking eyes, markedly reduced urination, or is hiding and unusually quiet. Those changes may occur with dehydration or illness, but only a veterinary professional can assess what is happening.
Safe home care while you wait
Home care is mainly about keeping your cat comfortable, hydrated, and easy to assess while you arrange veterinary advice. Keep several bowls of clean water available, especially in the rooms where your cat rests. Wet food may help increase fluid intake for cats that will eat it.
Do not give human anti-diarrhea medicines, painkillers, antibiotics left over from another pet, or electrolyte drinks intended for people unless a veterinarian specifically tells you to do so. Several common products are unsafe for cats, and some can hide symptoms that the clinic needs to evaluate.
Do not abruptly switch through several foods in an attempt to stop the diarrhea. Constant food changes can make the pattern harder to interpret and may upset the gut further. If your veterinarian recommends a temporary diet or a veterinary probiotic, follow their instructions on the food, portion size, and transition.
For an adult cat that is eating, offer normal small meals unless your veterinary clinic tells you otherwise. Cats should not go without food for extended periods, particularly if they are overweight or already unwell. Tell the clinic if your cat has eaten little or nothing for a day, or sooner for a kitten or a cat with other symptoms.
Keep the litter box exceptionally clean and use unscented litter if that is your cat’s usual choice. This makes it easier to see how often your cat passes stool and whether its consistency changes. If there are multiple cats, separate the affected cat when practical so you can track output and reduce shared-litter exposure.
What information to track for the vet
Write down when the diarrhea started, how often it happens, and whether the stool is soft, watery, mucusy, bloody, or black. Note any vomiting, appetite changes, weight changes you have noticed, increased thirst, and accidents outside the litter box.
List every food, treat, supplement, medication, and flavored product your cat has had during the past couple of weeks, including anything dropped on the floor or accessed outdoors. A new food is relevant, but it does not prove the food caused the problem. This history helps the clinic decide which possibilities to investigate first.
If your clinic asks for a stool sample, collect a small fresh amount in a clean, sealed container without litter mixed in. Refrigerate it only if the clinic tells you to or if you need to hold it briefly before the appointment. Ask the office how recent the sample needs to be.
Possible reasons diarrhea can persist
Persistent diarrhea can have many causes, including dietary intolerance, intestinal parasites, infections, stress, medication effects, and inflammatory or other digestive conditions. It may also occur alongside problems outside the digestive tract. The same stool appearance can have different causes, which is why a week of diarrhea deserves a veterinary conversation rather than a guess.
Outdoor access, a new cat in the household, boarding, recent adoption, raw food, and hunting can all be useful history to share. So can recent travel or a change in water source. Rather than blaming yourself, focus on giving the clinic an accurate timeline.
How to prevent a repeat episode
Once your cat is well, make food changes gradually over several days as directed by your veterinarian or the food manufacturer. Keep garbage, string, houseplants, and people food out of reach, since these can cause digestive trouble or worse.
Maintain regular parasite prevention and veterinary checkups that fit your cat’s lifestyle, especially for cats that go outdoors or live with other animals. Wash hands after handling stool and clean contaminated surfaces promptly. Some intestinal causes can spread among pets, so ask your veterinarian whether other animals in the household need attention.
Frequently asked questions
Can I wait if my cat is still eating?
For example, a cat that eats breakfast and plays normally but has had loose stool every day for a week still needs a call to the regular veterinarian that day. Eating is reassuring, but it does not rule out parasites, dietary problems, or other conditions. Seek urgent help sooner if blood, vomiting, pain, weakness, or reduced drinking occurs.
Should I fast my cat to stop diarrhea?
Do not fast a cat without veterinary direction. Unlike a person with a brief stomach upset, a cat that stops eating can run into problems quickly, especially if the cat is overweight, young, or already ill. Offer small normal meals if your cat will eat, unless your clinic gives different instructions.
Can stress cause diarrhea in cats?
A move, visitors, a change in routine, or conflict with another pet can affect some cats’ digestion. If diarrhea began around one of those events it is useful context for the veterinarian, but stress should not be assumed to be the cause after a week of symptoms. Medical concerns still need to be ruled out.
Is a probiotic safe for my cat?
Some veterinary-formulated probiotics are used for cats, but the right product and timing depend on the individual cat and the suspected cause. Avoid choosing a human supplement at random. Ask your veterinary clinic which product, if any, they recommend.
This post is for general informational purposes only and is not veterinary advice. Every cat is different — if you have concerns about your cat’s health or behavior, please consult a qualified veterinarian.