Can dogs have plums?
Sometimes – plum flesh can be okay in small amounts, but the pit is dangerous (choking/obstruction) and should be kept away.
Why it is or is not safe
Plum flesh is not considered toxic, but the pit is a major hazard and contains cyanogenic compounds. Plums are also high in sugar, which can cause diarrhea.
How to serve
Only give a couple small pieces of ripe plum flesh. Remove the pit and stem completely. Skip dried plums (prunes) because they’re concentrated and can cause diarrhea.
Symptoms to watch for
If the pit was swallowed: gagging, vomiting, abdominal pain, bloating, constipation, lethargy.
Sources: See full veterinary references here