Maria was woken up by a guard shaking her. The scientist was standing over her too, along with an assistant.
"Hello there Maria! We'll you've certainly developed since I last saw you! And judging by the morale of our guard force, I'm guessing you're much more cooperative now than you were before..."
Maria remained silent, laying on the bed looking up at him. One of her hands cupping a lower breast, the other between her legs, moving slowly. She could see the outline of the assistants hard-on through his trousers, he couldn't stop staring at her.
Finally he spoke up.
"S-sir, do you still want me to administer another injection?" He asked nervously, breaking eye contact with Maria briefly, then gazing back along her body when he was done speaking.
"I think this will be enough. I'd like you to remain here for twenty minutes just to take notes on the effects though, then I'll come back and we'll move her to the new location."
The scientist smirked, knowing full well his assistant wasn't going to get any work done in that time. This was for his own observational purposes.
Once they'd left the room, Maria sat upright, staring lustfully at the man in front of her. He pulled out a notebook, and approached her, reaching out to touch one of her ears.
"I-interesting... Almost indistinguishable from real horse ears..". While he was examined the top of her head, Maria was staring directly into his crotch. She leaned forward, gently rubbing her muzzle against it.
"S-stop that Maria... That's not why I'm here, I just need to examine your changes." He said, but his erection was telling Maria the opposite.
"If you don't back off Maria, I'm authorised to inject you again" he said, a little more authority in his voice this time.