📄 Article Highlights
- Hairballs (trichobezoars) form when cats swallow dead hair while grooming, which then accumulates in the stomach instead of passing through the digestive tract normally.
- Long-haired cats, those that shed heavily in spring and autumn, and older or stressed cats are most affected.
- A cat regurgitating a hairball occasionally is generally nothing to worry about; the real danger arises in the event of an intestinal obstruction, which is a veterinary emergency.
- Regular brushing remains the best preventative measure, followed by a fiber-rich diet, cat grass, and proper hydration.
- Loss of appetite, repeated vomiting without hair expulsion, a hard and painful abdomen, or the absence of stools should be treated as immediate warning signs.
If you live with a cat, you have undoubtedly heard that characteristic sound, either early in the morning or in the middle of the night: a few heaves followed by the discovery of a small, elongated, moist mass of hair on the carpet. Hairballs are a part of daily life in many cat households, and in the vast majority of cases, they are not a cause for concern. Here is how they form, how to limit them, and, most importantly, how to recognize the rare situations where they become a serious health issue.
How hairballs form in cats
Cats are extremely fastidious animals: they spend a significant portion of their day grooming, sometimes several hours in total. Their tongue, covered in small, backward-facing, rough papillae, acts like a brush that catches dead hair with every lick. Normally, this swallowed hair moves through the digestive tract and is passed in the stool without the cat or its owner ever noticing.
The problem arises when the amount of hair ingested exceeds what the intestine can naturally pass: the hair clumps together in the stomach to form a compact mass, a trichobezoar, which the cat eventually regurgitates in a cylindrical, elongated shape—quite characteristic once you have seen one before.
Which cats are most affected?
Certain factors clearly increase the frequency of hairballs:
Coat length and density
Long-haired or dense-coated breeds, like the Maine Coon or the Persian, naturally swallow many more dead hairs during grooming than short-haired cats, simply because they have more hair to maintain.
Shedding periods
In spring and autumn, seasonal shedding significantly increases the amount of dead hair, and therefore the risk of hairballs, even in short-haired cats that are usually not very affected.
Age
In senior cats, digestion gradually slows down, which can promote the accumulation of hair in the digestive tract rather than its regular evacuation.
Skin problems and parasites
A skin allergy, dermatitis, or a flea infestation can drive a cat to groom excessively to soothe itching, which mechanically increases the amount of swallowed hair.
Stress and excessive grooming
Some cats groom compulsively when they are stressed or anxious, a behavior that can also promote hairball formation, in addition to being a sign of distress that should be taken seriously.
A low-fiber diet
A diet low in fiber slows down intestinal transit and makes the natural passage of hair less effective, promoting its accumulation in the stomach.
In the majority of cases, it's not serious
It is worth repeating: a cat that occasionally regurgitates a hairball—say, once or twice a month for a long-haired cat—is not experiencing anything abnormal. It is actually a sign that the natural elimination mechanism is working as expected. The subject deserves your attention not because the phenomenon is dangerous in itself, but because there is a minority of cases where it can go wrong.
When a hairball becomes a real problem: intestinal obstruction
The real danger is not the hairball itself, but the possibility of it getting stuck in the digestive tract instead of being regurgitated or passed. When the digestive tract is partially or completely blocked, food and stool can no longer pass through normally: this is known as an intestinal obstruction, a veterinary emergency that may require surgery if not addressed in time.
Signs that should trigger immediate alarm
Certain symptoms justify an emergency veterinary consultation without delay:
- Repeated, frequent vomiting with no hairball being expelled
- Total loss of appetite lasting longer than a day
- A hard, swollen abdomen that is painful to the touch
- A complete absence of stools for several days
- Marked lethargy, a cat that is prostrate or less responsive than usual
- Visible efforts to gag or regurgitate with no results
These signs do not automatically mean it is an obstruction, but they always justify a quick veterinary opinion: it is better to have an examination that proves reassuring than an emergency addressed too late.
Prevention: regular brushing above all
The most effective, simplest, and least expensive method to limit hairballs remains regular brushing. By mechanically removing dead hair before the cat swallows it while grooming, you directly reduce the amount of hair passing through its stomach.
How often should you brush your cat?
For a long-haired cat, daily brushing is ideal, especially during shedding periods in spring and autumn. For a short-haired cat, two to three brushings per week are generally sufficient, except during periods of heavy shedding when more frequent brushing can be useful. Beyond hairball prevention, this brushing time is often enjoyed by the cat as a special moment of bonding with its owner, provided you go gently and respect its pace.
Other preventative measures
An appropriate diet
Certain kibble formulated specifically to limit hairballs contains more fiber, which promotes transit and the natural expulsion of swallowed hair through the stool rather than its accumulation in the stomach. This type of diet can be particularly useful for long-haired cats or those prone to frequent episodes.
Cat grass
Cat grass (often sprouted barley or wheat) is enjoyed by many cats and can facilitate the natural expulsion of accumulated hair by gently stimulating the digestive system. It remains a useful supplement, but does not replace regular brushing.
Good hydration
A well-hydrated cat has more efficient transit, which facilitates the natural passage of swallowed hair. A water fountain, several water stations in the house, or adding a little water to their food can encourage a cat to drink more, especially cats that do not drink much spontaneously.
Parasite control
Regular parasite treatment, especially for fleas, limits the itching that drives some cats to groom excessively, thus indirectly reducing the amount of swallowed hair.
Reducing stress
For a cat that grooms compulsively out of anxiety, working on the environment (quiet resting areas, hiding spots, enrichment, soothing pheromone diffusers) can help reduce this excessive grooming, in addition to a veterinary opinion if the behavior is marked or recent.
Anti-hairball pastes and supplements
There are pastes based on vegetable oils, available from veterinary pharmacies or your vet, which facilitate transit and the passage of hair through the intestine. They are useful in addition to a good brushing routine but should not be used as the sole solution in case of worrying symptoms: in that case, head to the vet rather than relying on self-medication.
Special cases to be aware of
Kittens
Hairballs are rare in very young kittens, whose grooming is still limited during the first few weeks. They generally appear as the cat grows and grooming behavior fully develops, often around a few months of age.
Strictly indoor cats
A cat that lives only indoors sometimes tends to groom more due to boredom or lack of stimulation, which can increase the frequency of hairballs. An enriched environment (toys, scratching posts, high-up observation points) indirectly helps limit this phenomenon.
Senior cats
In senior cats, slower transit and sometimes a decreased ability to groom effectively (e.g., due to arthritis, which limits movement) can alter the frequency and nature of hairballs. Any noticeable change in grooming behavior or appetite in an older cat warrants a veterinary opinion, whether hairballs are involved or not.
What to do while your cat is regurgitating a hairball?
The most useful reflex is to observe without intervening: most of the time, the cat handles the situation on its own in a few moments. You can then clean the area and make a mental note of how often these episodes occur, to detect any abnormal trend (a sharp increase in frequency, abnormally large or frequent hairballs, regurgitations without hair expulsion). This tracking, even informal, is valuable if you ever need to discuss it with your veterinarian.
Frequently asked questions
How many hairballs per month are considered normal?
There is no universal number, but for a long-haired cat during shedding season, one to two regurgitations per month are generally considered normal. For a short-haired cat outside of shedding periods, episodes more frequent than that deserve to be monitored or even discussed with your vet.
Can milk help my cat pass hairballs?
No, and it is actually discouraged: the vast majority of adult cats digest lactose poorly, and milk can cause diarrhea without actually facilitating the passage of hair. It is better to rely on brushing, hydration, and, if necessary, a diet or pastes specifically designed for this purpose.
My cat never has hairballs, is that worrying?
Not necessarily. Some cats, especially short-haired ones, swallow little hair or naturally pass it in their stool without ever regurgitating a visible hairball. The absence of hairballs is therefore not a warning sign in itself, as long as the cat is eating, digesting, and behaving normally.
Is brushing always enough to avoid hairballs?
Brushing greatly reduces their frequency but does not eliminate them entirely, especially in long-haired cats or those shedding heavily. This is why it is generally combined with other measures: an appropriate diet, sufficient hydration, and sometimes an anti-hairball supplement.
Should I worry if my cat vomits food along with hair?
An isolated instance of vomiting associated with a hairball is not necessarily concerning. However, repeated vomiting associated with a loss of appetite or lethargy falls outside the usual framework of a simple hairball and justifies a veterinary consultation to rule out other causes.
To help your cat limit hairballs on a daily basis, discover our selection in the Cat Hygiene collection.