A judge will decide whether to accept her plea deal next week, according to the Denver Post.
As part of the plea agreement, Manzanares and Solano have forfeited custody of Bubba.
Bubba, a male Akita mix, is currently living at the Auroa Animal Shelter and will need to undergo a behavior assessment.
Officials will then decide what will be the next best place to take him, according to the Arapahoe County District Attorney's Office.
Police began investigating in March 2017 after Solano reported a domestic violence incident involving Manzanares.
She later told an officer that they only had an argument, but that she was leaving Manzanares because he pressured her into having sex with their dog.
Solano claimed that she first discovered pictures of bestiality on the couple's shared laptop and confronted Manzanares about them, according to the Denver Post.
She said he told her to have an open mind and then began introducing her to bestiality videos, forums and literature.
The couple then began having sex with Bubba, which Solano said occurred inside a motorhome that Manzanares outfitted with a customized red padded bench to make it easier to copulate with the dog.
Manzanares used dog hormone spray to arouse Bubba and would take pictures and videos while they had sex with him.
Footage of the couple having sex with Bubba was later discovered by police.
Solano said she started to become 'somewhat jealous' of her boyfriend's relationship with their dog and that it would often lead to arguments.
When the couple were first arrested, authorities could not locate Bubba. Manzanares then forfeited his rights to the pet and officers were able to recover the poor pup.
Bestiality only became illegal in Colorado in 2007.