Disco 3 sunroof fan?

Hello all, I'm new to this forum, my name is G! I have a Disco 3 HSE, I also have a large wolf in a cage that I carry in the back. I would ideally like to cut a 5 inch diameter circle in the middle of the rear sunroof to put an electric fan in to keep him cool. is this possible? if yes, who can do it? and if it's not possible, does anyone have any other solutions.

Glazing company might. dont know if you can cut toughened glass though. can you not just leave the roof open.
Dog gets a shower when its rains granted but you cant have everything

The 2 rearsunroofs on the disco 3 are 1 sible piece of glass, and they don't open