The Cotoneaster plant contains cyanogenic glycosides so all parts of it are potentially poisonous. If its berries are swallowed, minor symptoms including nausea, vomiting, stomach ache, and diarrhea may occur. Cotoneaster can cause skin irritation, itching, and dermatitis a few hours after ingestion. Milk or water should be consumed if Cotoneaster is ever ingested. If the victim has received skin irritation and other skin complaints any exposed skin should be washed and medical attention should be sought.