When a toddler drinks spoiled milk, he or she may experience symptoms of food poisoning. The severity of symptoms depends on the child's general health, the amount of toxins in the milk and the amount of spoiled milk consumed, according to WebMD.

Contaminated milk and dairy products are associated with staph food poisoning, according to WebMD. Food poisoning generally affects the stomach and gastrointestinal tract. Symptoms of food poisoning, including staph strain, include diarrhea, nausea, vomiting and stomach cramps.

The most common complication of food poisoning is dehydration, according to WebMD. It is important to ensure sufficient hydration for a child experiencing food poisoning symptoms.