You understand your cat's patterns, her likes and her dislikes. You know when she's feeling frisky and happy and when she's not on her game. Her litter box provides a wealth of information about her health: her urine output and the consistency of her poop. A cat producing loose stool could simply be suffering from an upset tummy or be more seriously ill.
As the tender of the litter box, you know exactly what your cat leaves behind for you to pick up after, which means you understand what's normal for her. Generally, a cat will poop at least once a day, and if all is well, she's leaving behind a dark brown, well-formed deposit for your easy scooping. Once in a while she may leave behind something a little more challenging to clean up -- that regularly tidy little log is more like a mud pie or a bit of soft-serve ice cream. Whether you call it loose stool, runny stool or diarrhea, it all adds up to the same thing: It's out of the ordinary for your cat.
Loose stool can be the sign of a wide variety of medical conditions. Parasites such as Giardia, coccidia and roundworms are common culprits behind runny poop. Viral or bacterial infections, such as feline immunodeficiency virus and salmonella, are also potential causes. Other illnesses affecting the consistency of your cat's stool include colitis, liver disease, pancreatitis, inflammatory bowel disease and cancer and tumors in the digestive tract. If your cat's earned senior status, she also may have developed one of the common conditions among older cats, including hyperthyroidism or kidney disease, that include loose stool among their symptoms.
Sometimes it's a simple matter of food making a mess of things. Food allergies or intolerances, a change in diet or eating spoiled or rancid food can cause loose stool. Though not part of her regular menu plan, a curious cat may ingest plants, toxins or scavenged garbage or food to wreak havoc on her digestive system, and if she's swallowed something she shouldn't have, it can obstruct her intestines for a similar effect. If your cat's been under some extra stress -- perhaps a new living situation or an addition to the family -- it may show up in the litter box.
Going to the Vet
If your cat seems to be feeling well otherwise, give her a day or two to see if things firm up. Dr. Karen Becker of HealthyPets.com recommends withholding food, but not water, for 12 hours if a cat has experienced diarrhea but otherwise appears well. After 12 hours, offer her plain canned pumpkin and cooked ground turkey. Feed her a 50/50 mixture for up to three days, waiting for her loose stool to resolve. If it does not, or she appears lethargic or dehydrated, she should see a vet. As well, if her stool contains mucus, is black and bloody or she is vomiting, has a fever, and is uninterested in food, she requires professional assistance. Dr. Becker advises taking a stool sample to the vet with you, placing a quarter-sized sample on a piece of cardboard, kept in a plastic baggie.
Keeping it Firm
Ultimately your cat's treatment depends on what's causing her diarrhea. However, if she's a healthy girl, you can take steps on your own to keep things firm. Stay away from dairy products, including yogurt and milk, as some cats have difficulty digesting them. If you change cat food, take care to introduce the change gradually so as not to upset her gastrointestinal system. Mix progressively smaller amounts of her old food with her new food to transition her to her new diet. Keep tempting things, such as irritating plants, out of her grazing reach.