Cats don’t typically seek out and eat their own hairballs on purpose. What most owners are seeing is one of two things: either the cat is re-ingesting a freshly vomited hairball as part of an instinctive scavenging response, or the cat has a broader pattern of eating non-food items, a condition called pica. Both have different causes and different implications for your cat’s health.
What’s Actually Happening When a Cat Eats a Hairball
Cats are obligate carnivores with strong instincts to consume anything that smells like food, especially protein. A freshly regurgitated hairball is coated in stomach fluids and partially digested material, so to your cat, it doesn’t register as waste. It registers as something edible. This is especially common when hairballs are vomited up shortly after a meal, since the mass is mixed with food the cat was already digesting.
In many cases, this is a one-off behavior that doesn’t signal anything wrong. Cats in the wild wouldn’t leave regurgitated material sitting around, both because it could attract predators and because wasting calories goes against survival instincts. Your housecat is acting on that same programming.
Pica: When Eating Non-Food Items Becomes a Pattern
If your cat regularly eats hairballs, or also chews and swallows things like fabric, plastic, or cardboard, the behavior may fall under pica. This is a recognized condition in cats where they compulsively ingest inedible materials. Researchers have proposed several explanations, and the real answer is likely a combination of factors rather than a single cause.
Anxiety and compulsive behavior are among the leading theories. Some veterinary behaviorists classify pica as a compulsive disorder secondary to stress, similar to how conflict, frustration, or boredom can trigger over-grooming. Indoor-only cats show higher rates of pica, which initially led researchers to suspect that a lack of stimulation was driving the behavior. However, a large case-control study found that pica doesn’t appear to be the direct consequence of a suboptimal environment or early weaning, suggesting the picture is more complex than simple boredom.
Gastrointestinal problems may also play a role. Cats with pica vomit significantly more often than cats without it, and researchers note it’s hard to untangle cause and effect. Some cats may be eating unusual items, including regurgitated hairballs, to try to soothe nausea or digestive discomfort from conditions like inflammatory bowel disease or motility disorders. Redirected hunting behavior, genetic predisposition, a craving for fiber, and neurological disruptions in appetite control have all been proposed as contributing factors as well.
Over-Grooming Creates More Hair to Swallow
The more hair a cat swallows, the more hairballs form, and the more opportunities there are for the cat to re-eat them. Stress-related over-grooming is one of the most common reasons cats end up with excessive hairballs in the first place. Situations of conflict and anxiety, particularly tension with other cats in the household or changes in the home environment, can lead to compulsive licking that starts as a displacement behavior and escalates over time.
Food allergies are another overlooked trigger. Skin irritation from an allergic reaction causes itching, which leads to more grooming, which means more hair ingested. If your cat is grooming obsessively and producing frequent hairballs, an underlying skin issue or allergy could be fueling the cycle.
When Hairballs Become Dangerous
Most hairballs pass through the digestive tract without incident, either vomited up or eventually excreted in feces. The concern arises when a mass of hair gets stuck. A hairball trapped in the esophagus can cause obstruction and, over time, inflammation and scarring. One that moves into the small intestine can cause partial or complete blockage, leading to vomiting, abdominal pain, and visibly swollen loops of intestine that a vet can sometimes feel during an exam.
Smaller clumps may cause intermittent discomfort as they work their way through, eventually passing on their own. Larger ones can require surgical removal. Research on cats who needed surgery for intestinal hairball blockages found that biopsies taken during those procedures frequently revealed chronic intestinal inflammation or, in cats over 10 years old, intestinal lymphoma. This suggests that cats who form large, problematic hairballs may already have underlying digestive disease making them more susceptible.
Reducing Hairballs With Diet
Fiber is the most well-studied dietary tool for hairball prevention. It helps move swallowed hair through the digestive tract before it can clump into a mass. In one study, cats given a supplement containing psyllium (a soluble fiber) saw a 29% reduction in hairball-related symptoms over two weeks. Another found that adding just 4% cellulose to the diet reduced hairball severity. Sugarcane fiber showed a dose-dependent effect: the more fiber added, the fewer hairballs formed, though meaningful results required relatively high inclusion levels (10% or more of the diet by weight).
Commercial “hairball formula” cat foods typically work by increasing fiber content. If your cat isn’t interested in switching foods, oil-based hairball gels are available over the counter. These lubricants coat swallowed hair and help it slide through the intestines. They’re given by mouth, often by placing a small dab on the cat’s nose or paw so they lick it off, and work best when given between meals.
What to Do If Your Cat Eats Hairballs Regularly
An occasional re-eaten hairball is not cause for alarm. If it’s happening frequently, start by looking at the bigger picture. Is your cat grooming excessively? Are there new stressors in the home, like a new pet, a move, or a change in routine? Does your cat also chew or eat other non-food items?
Increasing environmental enrichment, adding more fiber to the diet, and addressing sources of anxiety can all reduce both hairball frequency and the compulsive behaviors that lead to re-ingestion. Regular brushing removes loose fur before your cat can swallow it, which is one of the simplest and most effective interventions. For long-haired breeds or cats that groom obsessively, daily brushing can make a noticeable difference within weeks.
If your cat is vomiting hairballs more than once every few weeks, losing weight, eating less, or showing signs of abdominal discomfort, the hairballs may be a symptom of a digestive condition rather than just a grooming byproduct. Chronic intestinal inflammation and food sensitivities are both common in cats and both increase hairball formation.