The cause of the shallot poisoning in dogs and cats was the inability of the body to produce enzyme that could digest this material. The dose of poisoning depended on the animal size. Shallot poisoning caused anemia in Heinz body. Heinz body is a small bubble that stood out from red blood cells and could be seen when the cell was colored. This bubble was the weak spot in red blood cells and caused the decline of the living period and dropped or the red blood cells will outbreak before the time.
The effect of shallot poison stayed same although being given in a raw, cooked or drought. Hemolytic happened several days after the shallot was eaten (hematocrit lowered around 5 days after being eaten). Every day shallot giving could cause the cumulative effect of the Heinz body continually opposed the single opening with the wide gap, until the following opening, gave time of bones marrow to form again red blood cells that broke before the time. Moreover the shallot could also cause liver damage, vomited, diarrhea, and uncolored urine. Here are some suggested books to read: The First Aid Companion for Dogs & Cats; Dog First Aid Emergency Care for the Hunting, Working, and Outdoor Dog; The Poisons and Antidotes Sourcebook