Why vomiting changes the next steps
Since your cat already had vomiting induced at the clinic, the focus shifts to monitoring rather than toxin removal. Mustard seeds contain compounds that can irritate the stomach lining and affect heart rhythm, but prompt vomiting reduces how much enters the bloodstream. The vet’s charcoal treatment helps catch anything left in the gut, though some absorption may still occur over the next 6-12 hours.
Watch for signs like excessive drooling or pawing at the mouth, which suggest lingering throat irritation from the seeds’ sharp edges. Your cat may also refuse food initially—this is normal after stomach upset. The vet’s medications might make her unusually drowsy; keep her in a quiet space away from stairs or other pets.
Tracking hydration after veterinary treatment
A 3.5 kg cat dehydrates quickly after vomiting, especially if she’s not drinking voluntarily. Check her gums—they should be moist and pink, not tacky or pale. Gently pinch the skin at her shoulders; it should snap back immediately. If you notice sunken eyes or sluggish skin retraction, contact your vet for possible subcutaneous fluids.
Offer room-temperature water in a shallow dish every hour, but don’t force it. If she refuses, try dripping water from your fingers or offering ice chips to lick. The vet may have sent home a recovery diet like boiled chicken or prescription gastrointestinal food—start with teaspoon-sized portions every 3-4 hours once she’s alert.
Heart rate and movement in the first day
Mustard compounds can temporarily speed up or disrupt heart rhythms, especially in small cats. When she’s resting calmly, place your hand on her chest behind the left elbow to count beats for 15 seconds, then multiply by 4. Normal range is 140-220 bpm; call the vet if it stays above 240 or below 120 when awake.
You might see mild muscle twitching or unsteadiness when she walks, which could signal electrolyte imbalances from vomiting. Keep her confined to one room with soft bedding to prevent falls. Avoid sudden noises or movements that could startle her—an elevated heart rate now puts extra strain on her system.
When to call the vet again before 48 hours
While most cats recover fully within two days, certain signs demand immediate follow-up. Red-flag symptoms include vomiting after the first 12 hours, seizures, or collapse. More subtle warnings are prolonged lethargy (sleeping constantly without grooming), diarrhea with blood, or failure to urinate for over 24 hours.
If her breathing becomes rapid (over 40 breaths per minute while resting) or she adopts an odd posture—like crouching with elbows out—it could indicate abdominal pain. Document any abnormalities with your phone’s video to show the vet. They may recommend repeat blood work to check liver enzymes or potassium levels, especially if she had pre-existing conditions you haven’t mentioned yet.
The full verdict, portion guidance and serving notes are collected on the Mustard seeds food facts page.