United Kingdom: Can I consider pets as "evidence of family members staying in their country of origin while traveling"?

I have applied for a standard visitor visa in the UK for myself, my wife and my children. I have elderly parents who are left behind, but do not live with me or are dependent, nor did I mention them as such in the application.

We have a dog (for 5 years) whom we consider as a family and have strong emotional ties and attachments to him. He will be in a pet care service for the duration of our visit.

  1. Can I mention my pet as a member of the family that was left in my cover letter? I can provide documentation of your vaccination records for the past 5 years, mention my name and address, as proof that I care for and take care of it.

  2. Can I mention my parents in my cover letter? Do I need to provide some documentation for them?

Please report as soon as possible. Thank you.