What yellow liquid usually is
Yellow liquid in vomit is most often bile, a digestive fluid made by the liver. Seeing it generally suggests the stomach was empty or nearly so, but it does not tell you the underlying reason. In kittens, vomiting of any kind deserves more caution than in adult cats because small bodies can become dehydrated and weak quickly.
Why kittens may vomit yellow liquid
- Too long without food. Kittens need to eat often. If they go a long time between meals, bile and stomach fluid can irritate the stomach.
- Eating things they should not. Kittens chew toys, plants, string and dirt. Some of these can irritate the stomach or cause a blockage.
- Parasites or infections. Worms and tummy infections can cause vomiting in young cats.
- A sudden diet change. Switching food quickly can upset a young stomach.
- Other illness. Many conditions cause vomiting, and a vet is needed to sort them out.
For adult cats and the bile-colour discussion, see cat vomiting green bile. For food that comes up undigested, see kitten throwing up undigested food.
What to watch
After an episode, keep an eye on:
- Energy and playfulness
- Appetite and willingness to drink
- Litter box use, including diarrhoea or no stool
- Belly appearance and any signs of pain
- Whether the vomiting happens again
If the kitten threw up once and then eats, plays and acts normal, it may be a one-off. Still, many vets prefer to hear about vomiting in kittens, so a phone call is reasonable.
When to call the vet
Call your veterinarian promptly if your kitten:
- Vomits more than once
- Seems tired, weak or hides
- Refuses food or water
- Has diarrhoea
- Has a swollen or painful belly
- Has blood in vomit or stool
- May have swallowed a toxin, plant or object
- Is not yet vaccinated or dewormed
Bright neon yellow vomit can happen for several reasons, including food or supplement colouring, but it is worth mentioning to your vet if it appears with other signs.
What you can do
While you arrange advice, provide fresh water, keep the kitten warm and calm, and note details such as timing and a photo of the vomit. Do not give human medicines or home remedies. Ask your vet whether to hold food or continue small meals, because a young kitten should not go without food for long.
Feeding routine
Feeding smaller meals more often, as your vet recommends for the kitten’s age, can reduce the chance of an empty stomach. Introduce new foods gradually. If you have several kittens, make sure each one gets enough to eat without gulping.
Frequently asked questions
What is bilious vomiting syndrome?
It is a condition in which a cat vomits bile, often in the early morning or after long gaps between meals. A vet should diagnose it after ruling out other causes.
What is the silent killer of cats?
This phrase is often used for illnesses that stay hidden for a long time, such as kidney disease. It is not specific to yellow vomit, but it is one reason repeated vomiting should be checked. See old cat throwing up a lot.
Should I feed my kitten after vomiting?
Ask your vet. Advice depends on the kitten’s age and condition.