What vomiting within 30 minutes tells you
That rapid reaction suggests direct stomach irritation rather than systemic garlic toxicity—her body rejected the pesto before much absorption occurred. The vomit's appearance matters: if it's mostly clear or foamy with just a pesto streak, she likely expelled most of the offending substance. Chunky vomit with food remnants means her stomach emptied completely.
Hydration becomes the priority now. Offer ice chips rather than a full water bowl to prevent gulping that could trigger more vomiting. Dab a bit of water on her gums if she's reluctant to drink. Dehydration escalates quickly in cats—check for skin tenting by gently pinching the scruff; it should snap back immediately.
Pale gums versus bright pink
Garlic's compounds can make gums pale or yellowish over hours, but at this early stage, color changes would stem from stress or nausea. Lift her lip in good lighting—the gums should match bubblegum pink, not whitish or gray. Press briefly with your thumb; the blanched spot should regain color within two seconds.
Any delay in color return or noticeable stickiness when you touch her gums means circulation issues are developing. These warrant an immediate vet visit regardless of vomiting frequency. Cats compensate well until they crash suddenly, so subtle changes matter more than dramatic symptoms.
Why frequency differs from quantity
A single lick rarely delivers enough garlic for true poisoning, but sensitive cats react strongly to trace amounts. Compare this to a cat eating a whole garlic clove—the latter causes red blood cell damage days later, while your case involves acute irritation. The pesto's salt and acidity likely contributed as much as the garlic itself.
Watch for secondary symptoms like pawing at the mouth or exaggerated swallowing, which suggest esophageal irritation. Unlike dogs, cats rarely drool visibly—wetness around the chin or a consistently damp paw (from face-wiping) counts as abnormal moisture.
The next four hours if vomiting stops
If she keeps water down for two consecutive hours, offer a teaspoon of plain boiled chicken or her regular wet food. No dairy—despite pesto's cheese content, cats can't digest lactose well when ill. Appetite is a positive sign, but don't be alarmed if she skips one meal; stomach lining needs time to recover.
Lethargy lasting beyond six hours post-vomiting means her electrolytes could be dipping. Try engaging her with a favorite toy—normal curiosity returning is reassuring. If she just watches blankly or tucks her paws tightly under her body, professional rehydration may be needed.
The full verdict, portion guidance and serving notes are collected on the Pesto food facts page.