The risk of GI problems is pretty high, particularly when they are given in high amounts. Moreover, dogwood berries have large seeds, which means excess feeding can lead to bowel obstruction, especially in cats and small dogs.
As these berries are considered slightly poisonous, their consumption is unlikely to have a negative impact on the liver or kidney functioning. Also, till date, there have been no cases of organ failure in pets arising from ingesting dogwood berries.
Too much consumption can be problematic for your health. You got to be more careful, particularly when giving this to small children, as they may choke on the berries due to their large seeds. To be on the safer side, isolate the pits and seeds from the berries before giving them to children. All in all, don’t go overboard when eating dogwood berries. Having them in moderation or in small amounts is not a cause for concern
On the whole, while the health risk is minimal when feeding a few berries, giving in large quantities is a cause for concern, and most likely to upset the digestive system of your pet. However, to be on the safer side, it is advisable to altogether avoid feeding berries to your pet cat or dog.