I asked around and did some reasearch few days after Gingerbread died, and based on his symptoms it was heat stroke. He died during the summer (this story was on my draft for few months and I just had the time and courage to finally edit and post it), during that month it was really hot in the city where we live and since I just moved to a new apartment, I don't have an airconditioner at home then 😥. He wasn't able to withstand the terrible climate back then and passed away.
RE: A Heartbreaking Farewell: Goodbye My Gingerbread