Vomiting is a common symptom in cats with kidney disease, and can lead to dehydration and intensification of the disease if left untreated. If your cat starts vomiting, refrain from giving them any water or food at all for an hour to allow their condition to stabilize.
Once an hour has passed, give them a small amount of water and monitor their condition. If they seem to be fine, slowly resume feeding them small amounts of food. Administration of any supplements or drugs should be suspended until their conditions have stabilized, and should be given in small doses initially.
However, if your cat continues to vomit even despite these measures, or if their condition and energy levels continue to decline, you should take them to a veterinary clinic for a checkup as soon as possible. This is especially vital for cats with kidney disease due to the frequency of their vomiting.
As such, getting antiemetics (used to prevent and treat vomiting) from a veterinary clinic in advance can help you be prepared for such issues. Antiemetics are effective at preventing vomiting when given once a day, and tend to have less side effects than other medications, which generally makes them a safe choice for cats with kidney disease.
In summation, advance preparation, close monitoring, and immediate response can help you manage vomiting in cats with kidney disease.
