Ask a Vet with Dr. Sam: What are hairballs and why do cats get them?

Hairballs (formerly known as trichobezoar) are wads of undigested hair. Despite their name, they are most often cylindrical in shape due to their journey from the stomach through the esophagus. If you are brave enough to examine a hairball, you will find that it is likely the same color as your cat’s fur, moistened by bile and other digestive fluids (ew!).

Hairballs are a byproduct of grooming. As your cat grooms themself with their rough tongue, the papillae on its surface will lead indigestible hair down their throat and into their stomach. Most of this hair passes through the digestive tract but some of it stays in the stomach and forms what will eventually emerge as a hairball.

It is not uncommon for cats to vomit up the occasional hairball. Hairballs can potentially create life-threatening blockages in the digestive tract so if your cat is lethargic, refuses to eat for more than a day, or has episodes of unproductive vomiting you should consult your veterinarian immediately.

To reduce the risk of hairballs and their complications, you can brush your cat regularly and be sure to keep dangerous hairball ingredients like elastics, twist ties and paper clips out of reach from your cat.

Do you have a question for Dr. Sam? Email yours to steph@mrfrs.org.