How to say this?

Hi! everyone,I hope you are enjoying good life.
I have come across a situation where I have to describe ,why I named my Great Dane "Tommy"?
In a pet forum someone has asked me,why did I name my dog "Tommy"?
Now I want to explain to him something like this It may sound a bit odd to you.
My answer-:Actually It is being passed on by our ancestors that we name every dog we keep "Tommy". (Now I want to know,what is this act of naming every dog we keep "Tommy" called? As per the dictionary it says "Heirloom" but heirloom means-a valuable or special possession that has belonged to a family for many years. (Can I use "Heritage" instead of "heirloom" How can I fit these two words in my answer (colored))
I know "naming every dog we keep as a pet "Tommy" is not a valuable possession but it is something special in our family being passed on by our ancestors.My grand father(Late) had had a greyhound he also named him "Tommy" and then my father(Late) had kept a pitbull in his life he also had named him "Tommy" and now I maintaining the family tradition or you can say Lineal habit (Am I right here?)also has named my dog "Tommy".
I hope you have understood what I want to say?"
Please tell me Is my answer right?
How should I explain this correctly?
Thanks!