TL;DR: Eating grass is a common instinctual behavior for cats to help clear their digestive tracts, but frequent vomiting, blood, or lethargy requires veterinary attention.
Why is my cat eating grass and vomiting?
Cats are instinctive hunters and explorers, and eating grass is a common behavior. Because cats lack the necessary enzymes to fully digest plant matter, the grass often acts as a natural emetic. This causes them to vomit, which helps clear their digestive tract of indigestible materials such as fur, feathers, or bone fragments. In many cases, it is simply a way for your cat to settle an upset stomach.
Is my cat eating grass a medical emergency?
- Urgency level: Low. Occasional grass-eating and vomiting is typically not an emergency if your cat appears healthy, active, and has a normal appetite.
- Contact a veterinarian if:
- The vomiting becomes frequent (multiple times a day).
- There is blood present in the vomit.
- Your cat appears lethargic or refuses to eat.
How does taking a photo of my cat's vomit help with veterinary triage?
- A clear photo allows the vet to inspect the color, consistency, and contents of the vomit.
- It helps professionals differentiate between a standard hairball clearing and more concerning signs like bile or blood.
- Images help identify the presence of toxic plant fragments or other foreign materials.
Clinical Context (Merck Veterinary Manual)
Cats are known to vomit, particularly when attempting to dislodge hairballs. Dietary indiscretion, including the ingestion of grass or other foreign material, can induce vomiting of sudden onset. Vomitus may contain bile, food, froth, blood, or evidence of ingested substances. While frequent in cats, chronic vomiting may indicate underlying thyroid, liver, or kidney dysfunction and warrants further investigation.
Chapter: Pharmacology
Source: The Merck Veterinary Manual, 11th Edition (Page 2547)