Was thinking about this before replying. One thing you may do is use flexi tubing (the tubing repair shops attach to the exhaust pipe that gets routed to the outside of the building) that is clamped to the exhaust pipe and routed under the trailer. Not sure how that would work but perhaps worth a shot. Just a couple pennies worth of info at best.
Really CO is not an issue especially in an open environment. Pre pollution control days yes but not now. Diesel fumes would be a lot worse. Used to be you could kill yourself with your car in an enclosed garage, now nothing happens, it's my line of work, not the killing self but working with suicides.
Try it with a cat first.(JK) As long as it is ventilated from somewhere away from the main exhaust stream I would think the dog would be OK. To be extra safe you could put a 12V fan in the top of the trailer to pull in fresh air.
I've been thinking the same thing, how to drag the hound around. I've seen a container made with this in mind that would mount to the tail plate of the bike. Don't think they make them though.
HF sells a solar fan. I don't worry about enough air when moving. More so for when I have to run into a gas station or something.
Problems with a fan running in the lid of the trailer is that eventually it will burn out from the bikes speed varying from the fans speed. I have seen them last as little as 2 minutes. The main thing about co emissions is to have the fresh air openings of the trailer out of the exhaust stream. I have spent many hours testing the trailer I built for my Lab to make sure it is safe for her. I can not post pics here so if you would like to see a pic of the one I built send me a pm with your email Brian
Canary. Used for early CO detection in mines since the beginning of mining, cheaper than an electronic detector too Really though it would be very difficult to get motorcycle exhaust to funnel into an enclosed trailer. The volume is small, I'd be more concerned of a truck running beside it.
Any new developments in the dog trailer world ? Not sure my boy would like it but might be worth a try.
I know riding behind a bunch of other bikes can quickly give me a headache. I'm sure it would be similar in s trailer, but there really isn't a way to tell. I'd definitely make sure there is a ton of ventilation sides and back, and maybe try to do some draft shaping to keep the exhaust flow away from the carrier.
I built one for my Yellow Lab 5 years ago and it has turned into a small business from requests from people we meet on the road. Ventilation is a must but also noise. I built mine with high density foam with fiberglass laid over. Jade has logged over 50,000 miles in her trailer, and if you move her trailer or hop on the red bike, which pulls the trailer, she is ready to go.
