Bezoars in Cats: Causes, Symptoms, and Prevention

What are bezoars, why do they form, and when do they become dangerous? More importantly, how can you protect your cat’s health? Here is what every cat owner should know.

What Is a Bezoar, and Why Does It Form?

A bezoar is simply a hairball — a wad of fur that collects in a cat’s stomach. To understand why it happens, you only have to watch a cat groom. As your cat licks her coat, the tiny backward-facing barbs on her tongue catch loose, dead hairs, and she swallows them. In small amounts, that hair passes harmlessly through the digestive tract and leaves the body in the stool.

The trouble starts when too much hair accumulates at once. Instead of moving along, the fur tangles together, mixes with stomach contents and stool, and forms a dense plug. That plug can slow digestion and cause constipation. In the most serious cases, it blocks the gastrointestinal tract completely, so that food entering the intestine simply backs up behind it. The cat cannot pass the mass on her own, waste builds up, and the body can become toxic. According to the Cornell Feline Health Center, while occasional hairballs are common and usually harmless, a hairball that causes an obstruction is a genuine medical emergency.

Under the combined pressure of a bezoar and undigested food, the intestinal wall can rupture.

When a blockage reaches that point, prompt surgical intervention is needed to save the animal’s life. That is exactly why prevention matters so much — and why it is worth knowing the warning signs early.

Symptoms of Bezoars in Cats

A few telltale signs suggest that hair may be building up in your cat’s stomach. The most common ones include:

• Changes in the litter box, such as constipation or other irregular stool
• Loss of appetite
• Lethargy or unusual apathy
• Vomiting, including hacking up hair or repeated unproductive retching
• Gradual weight loss

If you notice one or more of these signs, contact your veterinarian. Even if it turns out to be nothing more than minor indigestion, it is always better to be safe than sorry — especially because frequent vomiting and appetite changes can also point to other health problems. The American Veterinary Medical Association recommends a veterinary visit whenever these symptoms persist rather than waiting them out at home.

How to Deal With Bezoars

Large, established bezoars sometimes have to be removed surgically. The good news is that preventing them is well within every owner’s power. Because bezoars form from the fur a cat swallows, the whole strategy comes down to reducing how much loose hair ends up in her stomach in the first place.

Brush Your Cat Regularly

Hairballs peak during shedding season, when a cat swallows far more fur than usual and her body simply cannot keep up. Many indoor cats and dogs do not shed seasonally the way their wild relatives do — they shed all year round. That makes routine coat care essential. Put simply, the more you brush your cat, the less hair ends up in her stomach.

Choose a grooming tool that suits your cat’s coat type and feels comfortable in your hand. The options range from combs and brushes to grooming gloves, slicker brushes, and deshedding tools such as the FURminator. Deshedding tools tend to be the most effective because they pull dead hair from deep in the undercoat rather than just skimming the surface. Their popularity has unfortunately led to a flood of counterfeits, so buy from a reputable source.

Feed a Balanced, High-Quality Diet

Healthy cats tend to have healthy coats, and a healthy coat sheds far less. That is why good nutrition is your second line of defense. Lean toward high-quality, complete cat foods, and if you feed a home-prepared diet, ask your veterinarian about appropriate vitamin and mineral supplements. A skimpy or poorly balanced diet leads to excessive hair loss — exactly what you are trying to avoid. The ASPCA offers helpful general guidance on feeding cats well.

If your cat struggles with hairballs often, ask your veterinarian about a hairball-control formula designed to help fur move through the digestive tract. Whenever you switch foods, transition gradually over several days to avoid an upset stomach.

Use Hairball Aids

The third step is to give your cat a little help clearing fur from her stomach. Hairball pastes (often flavored gels), specially formulated treats, and cat grass such as sprouted oats can all encourage swallowed hair to pass through rather than collect.

Treats are the easiest aid to use, simply because most cats love them. Look for a line formulated for hairball control and stick to the recommended serving size. Cat grass works well for some cats and not others — a few will happily nibble it while others ignore it entirely. It is the same instinct that helps cats in the wild clear their digestive systems, so it is worth offering to see whether your pet takes to it.

These are the core ways to prevent bezoars. As you can see, protecting your cat’s health is often easier than you might expect — a little routine care goes a long way.

Frequently Asked Questions

Are hairballs in cats normal?

Occasional hairballs are common and usually nothing to worry about, especially in long-haired cats and during shedding season. What is not normal is frequent hairballs, repeated unproductive retching, or any sign of a blockage. If your cat seems to bring up hairballs constantly or shows other symptoms, talk to your veterinarian.

How often should a cat get hairballs?

There is no precise “normal” number, but most healthy cats produce a hairball only occasionally. A cat that is bringing up hairballs every week or two, or struggling to pass one, should be evaluated by a veterinarian, as this can signal excessive shedding, over-grooming, or a digestive issue.

Can a hairball be dangerous for a cat?

Yes. While most hairballs pass without trouble, a large bezoar can cause constipation or a complete intestinal blockage. A blockage is a medical emergency that may require surgery, so seek veterinary care right away if your cat is vomiting repeatedly, refusing food, straining without producing stool, or acting lethargic.

Do indoor cats get more hairballs?

They can. Many indoor cats shed year-round rather than seasonally, and they often have more time to groom, so they may swallow more loose fur. Regular brushing, a quality diet, and hairball aids are especially helpful for indoor cats.

What is the best way to prevent hairballs?

Consistent grooming is the single most effective step, because the less loose hair your cat swallows, the fewer hairballs form. Pair frequent brushing with a high-quality balanced diet and, if needed, a hairball-control food or paste recommended by your veterinarian.