What to expect in the first 6 hours post-meal
At the 2-hour mark, any shell fragments large enough to cause trouble would already be triggering gagging or neck stretching. Since your cat is acting normally, the tails were likely well-cleaned. The main risk now is mild stomach irritation from the unfamiliar seafood proteins, which may cause a single episode of vomiting or loose stool.
Cats often groom excessively after eating something new—this isn't illness but self-cleaning. Watch for a pattern: occasional licking is normal, but frantic pawing at the mouth suggests a shell shard stuck in gums or throat. Offer water to help flush any tiny debris.
The 12-hour window for complications
Between hours 3-12, the primary concern is delayed gastrointestinal response. Crawfish is rich compared to most cat foods, so her system may produce softer stool tomorrow morning. This isn't diarrhea unless it's liquid or contains blood—just a natural adjustment to higher protein and moisture content.
True alarm signs would be repeated vomiting (more than twice), hunched posture indicating abdominal pain, or refusing even favorite treats. These suggest either an obstruction or severe intolerance, rare with plain tails but possible if she's sensitive to shellfish.
Hydration and feeding after seafood
Fresh water helps prevent constipation from the dense meat—some cats ignore their bowls after novel foods, so consider placing extras near her favorite spots. Her next meal should be her regular food; don't withhold food to 'rest her stomach' unless she's actively vomiting.
If she seems hungrier than usual, it's safe to offer 10% more at mealtime—the crawfish digest faster than her normal diet, leaving her temporarily unsatisfied. But resist giving more seafood; stick to her usual balanced nutrition to avoid gut flora disruption.
When to finally relax
Once 12 hours pass with no vomiting, normal litter box use, and steady energy levels, the risk period is over. Some cats get a slight fishy odor to their breath or coat for a day—this is just metabolic processing, not a sign of trouble.
Longer-term, watch stools at the next two bowel movements. Slightly looser form is expected, but persistent diarrhea beyond 36 hours means her gut didn't adjust properly. That's uncommon with plain crawfish but warrants a vet check to rule out coincidental parasites or other issues.
The full verdict, portion guidance and serving notes are collected on the Crawfish food facts page.