Why size and cooking method matter here
Your 15 kg dog swallowed what was likely a half-teaspoon of cooked liver at most. Heat alters liver's structure, making it easier to digest than raw—and less likely to irritate. At this body weight, their system can handle that quantity without needing intervention.
The immediate concern would be choking on a large piece, but since you saw it go down smoothly, focus shifts to monitoring rather than action. Their stomach acids are already breaking it down.
The real risks of inducing vomiting unnecessarily
Forcing vomiting risks aspiration pneumonia, especially in a panicked dog. Liver's soft texture means it's unlikely to cause obstruction, so the cons outweigh any theoretical pros. Plus, by now, the treat has left their stomach.
Emergency vets rarely recommend vomiting for fatty foods unless consumed in enormous amounts—we're talking multiple whole livers, not a training-treat-sized piece. Your vigilance is better spent watching for natural digestion.
What to expect in the digestion timeline
Over the next 4-6 hours, your dog might seem extra thirsty or lick their bowl more intently. This is normal—liver's strong flavor leaves residual taste. Actual vomiting would be unusual unless they have a known sensitive stomach.
Their next bowel movement may appear darker and smell stronger than usual due to the iron content. This isn't blood—just the liver passing through. Only worry if you see straining or watery diarrhea persisting beyond one elimination.
When "just watching" becomes active monitoring
Active monitoring means checking on them hourly until bedtime, noting energy levels and interest in toys. A content dog napping or playing as usual is a good sign. Panting or restlessness could signal mild discomfort.
Have their leash handy for extra bathroom trips tonight. If they suddenly refuse water or can't get comfortable lying down, those warrant a vet call. Otherwise, this will likely resolve as quietly as it began.
The full verdict, portion guidance and serving notes are collected on the Cooked liver food facts page.