If my dog has ingested onions, what immediate actions should I take to ensure their safety and well-being? Considering that onions are known to be toxic to dogs due to the presence of thiosulfate, which can lead to oxidative damage to red blood cells, how can I quickly ascertain the extent of the ingestion? Should I monitor for symptoms such as vomiting, diarrhea, or lethargy? What are the critical timeframes for seeking veterinary assistance? Is there a specific quantity of onion that would necessitate urgent attention, or does it vary based on my dog’s size and breed? Moreover, what role does the preparation of the onions—raw, cooked, or powdered—play in the severity of symptoms? After contacting my veterinarian, what information should I prepare to facilitate their evaluation? Ultimately, what preventative measures can be taken to avoid such situations in the future, ensuring my furry friend remains safe and healthy? Insights into this matter would be greatly appreciated.