Nutmeg. You may not realized this but high levels of nutmeg can be toxic, even fatal. The toxic principle is not well understood. Signs of toxicity include tremors, seizures, nervous system abnormalities or death.

Onions or Garlic. Dogs and cats lack the enzyme necessary to properly digest onions and this could result in gas, vomiting, diarrhea or severe gastrointestinal distress. If large amounts of onion or garlic are ingested or onions are a daily part of your dog's diet, the red blood cells may become fragile and break apart. This is due to the toxic ingredient in onions and garlic, thiosulphate. Signs can begin immediately after eating the onion or a few days later. Large quantities of garlic need to be ingested before signs of toxicity are seen. Severe anemias and even death can occur if the dog ingests lots of onions or garlic and receives no treatment.

All forms of onion and garlic are a problem. This includes raw, dehydrated, cooked, powders or those in foods. The most common source of onions for cats is in human baby food. Some baby foods have onion powder added for taste. When consistently fed baby food with added onion powder, signs of toxicity can develop. Many people use garlic pills as 'natural' flea control. The amount of garlic is low but if large amounts of the pills are ingested at one time, toxicity may occur.