When a cat is vomiting, vets may suggest waiting to feed and offering plain, cool water only, for a few hours, then offering small amounts of food. Depending on the glucose level (are you home testing?) and whether or not your cat has experienced ketones, you may want to skip insulin for one shot or give a reduced dose.
Freeze dried chicken (ex PureBites, get the dog sized for better cost per ounce, and crumble smaller), may be used to perk appetite, but is not complete nutrition.
A/D is pretty high fat, which may not go down too well on an upset stomach.
If you are give a long-acting insulin such as Lantus, Levemir, ProZinc, or PZI, as the glucose lowers, hunger should be experienced and the cat begin eating unless a severe condition is being experienced (ex pancreatitis).
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Editing your Signature
In the upper right corner of the screen, within the dark blue bar, you will see ID, Inbox, and Alerts
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Add any other text, such as your name | cat's name | date of Dx (diagnosis) | insulin | meter general location (city and state/province) any other pertinent issues like if there are any food issues, history of DKA, hepatic lipidosis, pancreatitis, allergies, IBD, etc.
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