Mimo has been diagnosed twice with mast cell tumors, which is a form of skin cancer that releases a dangerous toxin called histamine. When these tumors are manipulated, it can cause an anaphylactic reaction. Most of the time it is slow to spread but can affect the spleen, intestines, and kidneys. It is important to check early any suspicious masses before it spreads and is easy to remove. So far both of Mimo surgeries have been successful.