Updated On September 23rd, 2025
Pet's info: Cat | Domestic Shorthair | Female | spayed | 10 years old | 13 lbs
My cat was diagnosed with a UTI yesterday afternoon. She was prescribed Clavacillin (62.5 mg) and Onsior (6 mg). About 6.5-7 hours after her medicine she started throwing a foamy, yellow liquid and then all of her dinner. During the night, I woke up twice to her throwing up a foamy liquid with a slight color to it. I know the vet said the Clavacillin could upset her stomach but is this normal? Does she need to be brought to the ER or can she wait until her primary opens in a few hours?
1 Answer
Published on March 30th, 2021
Poor Rajah! It is very possible the med (or underlying illness) are upsetting her stomach. Vomiting up yellow foam/bile can also sometimes occur if the stomach is too empty and also upset. Offering several smaller bland meals (if she's stopped vomiting) may help reduce upset. That said, I would definitely let your vet know once they are open in case they want to adjust her dosage, have her brought in for supportive care (such as fluids or shots to reduce vomiting and dehydration) or change the med used entirely. If she's vomiting so much to the point she is weak and cannot move, seems in severe distress or pain, or otherwise is worsening rapidly, and your vet isn't open yet, seeking out ER care is best then.
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