Why last night's timing changes the risks
Since your 10 kg dog chewed the leaves over 12 hours ago without vomiting, the worst-case scenarios are off the table. Poinsettia's irritants act quickly or not at all — delayed symptoms usually mean mild intestinal grumbling rather than acute crisis. However, monitor his next bowel movement for unusual mucus coating, a sign the sap irritated his lower digestive tract.
His weight works in his favor here: a 10 kg dog would need to consume several whole leaves to risk more than transient drooling. If he merely nibbled edges, the sap exposure was likely minimal. Check his usual napping spots for discarded leaf fragments — some dogs discreetly spit out the bitter plant material.
Late-onset symptoms you might still see
Some dogs show subtle signs like eating grass obsessively 12–24 hours later, their attempt to soothe residual gut irritation. Your dog's size makes this behavior more noticeable than in tiny breeds — watch for repeated, deliberate grazing rather than casual mouthing of lawn.
Another delayed reaction is temporary soft stools, often with a faint metallic smell from sap compounds altering gut flora. This isn't dangerous unless it progresses to watery diarrhea or lasts beyond two meals. Offer plain pumpkin purée (not pie filling) with his next meal to gently regulate his digestion.
Assessing his mouth 18 hours later
Gently lift his lips to check gum color — lingering irritation might show as slightly paler pink lines along the teeth. Poinsettia sap rarely causes lasting damage, but a 10 kg dog's vigorous chewing could have left minor abrasions that feel gritty to him. Refusing crunchy treats while accepting soft food hints at residual mouth sensitivity.
If he's hesitating before drinking water, try offering it from your palm first. Some dogs develop a temporary aversion after associating the water bowl with post-poinsettia nausea, even if they never actually vomited. This usually resolves within 48 hours.
When to resume normal monitoring
After 24 symptom-free hours, your 10 kg dog is almost certainly in the clear. The one exception would be if you later find he actually ingested large quantities — say, a whole branch — rather than just chewing leaves. In that unlikely scenario, watch for loss of appetite or unusual lethargy over the next three days.
Prevent future incidents by placing poinsettias where his standing height can't reach them. A 10 kg dog's muzzle is typically 12–18 inches off the ground when standing — measure your plant placements accordingly, remembering he can stretch further when motivated.
The step-by-step response, from the first minute to the vet visit, is in our Poinsettia emergency guide.