What was the original form of Tonks's Patronus?

Question

Early in Harry Potter and the Half-Blood Prince, Harry observes Nymphadora Tonks casting the Patronus Charm:

As Harry swung the cloak back over himself, she waved her wand; an immense silvery four-legged creature erupted from it and streaked off into the darkness.

"Was that a Patronus?" asked Harry, who had seen Dumbledore send messages like this.
_{^{- Harry Potter and the Half-Blood Prince (Chapter 8 - Snape Victorious)}}

Due to a comment by Snape, Harry determines that Tonks's Patronus must have changed forms recently, and he asks Lupin about it:

"Tonks’s Patronus has changed its form," he told him. "Snape said so, anyway. I didn’t know that could happen. Why would your Patronus change?"

Lupin took his time chewing his turkey and swallowing before saying slowly, "Sometimes … a great shock … an emotional upheaval …"
_{^{- Harry Potter and the Half-Blood Prince (Chapter 16 - A Very Frosty Christmas)}}

However, at no point does anyone identify what Tonks's Patronus used to be.

What form did Tonk's Patronus take before it changed?

Answer 1

Pottermore's article on the Patronus Charm, written by J.K. Rowling, answers this question:

The form of a Patronus may change during the course of a witch or wizard’s life. Instances have been known of the form of the Patronus transforming due to bereavement, falling in love or profound shifts in a person’s character. Thus Nymphadora Tonks’s Patronus changes from a jack rabbit to a wolf (not a werewolf) when she falls in love with Remus Lupin.

Therefore, Tonks's Patronus Charm took the form of a jack rabbit.

Answer 2

J.K rowling confirms that her Patronus changed from a Jack rabbit to a wolf on Pottermore. So that means her old Patronus was a Jack rabbit .