Gaius had been listening closely, although he'd not had anything to really contribute up until now. The suggestion that Sirius should use his Animagus form sent off alarm bells.
"I do not know if using Animagi in their animal forms is a good idea anyway," he said softly, looking at Sirius with concern. "I know that I've had a great deal of trouble even achieving my form lately, and there is always a chance we won't be able to turn back. Loss of voice and hands could be a bit problematic in some situations, yes?"