welcome to Justanswer! I am Dr. Altman and happy to assist you both today!
The serviceberry is in the plant genus / family called Amelanchier.
This plant is not one that I would consider safe for your landscaping if you have dogs.
The serviceberry contains toxins called cyanogenic glycosides.
When ingested they can cause vomiting, diarrhea, a lack of oxygen in the blood (cyanosis), a slow heart rate, breathing changes and if a lot is ingested, even seizures.
While grazing animals such as cattle (who would eat a lot) are more susceptible to toxicity, dogs when ingesting the plant / berries can have similar signs.
If your dog ingested this within the last hour then you can induce vomiting with 3% hydrogen peroxide 1 tsp per ten pounds (i.e. 2 tbsp & 1 tsp) then walk around to mix it in the stomach and agitate the lining. If no vomiting within 10-15 minutes it can be repeated once only in hopes of inducing vomiting.
I would definitely advise removing this plant from the area where your dog is exposed or at least sectioning it off in the future to prevent further ingestion of berries
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