Our lab suddenly started holding her head in the air sniffing . Very seriously sniffing. We were sitting in the family room with a 1/2 bath located off the family room. She kept holding her head in the air sniffing like we have never seen her do before.
My husband went into the bathroom and called me in there to show me that on the floor of the shower, there was a black powder type substance all over the shower floor. It looked something had exploded in the drain forcing a black powder to burst out of the drain. What could this be?

This black stuff is probably residue out of your shower drain, it was probably washed into the shower when a commode or washing machine was used. If you live in an apartment it could be coming from one of the other tenants apartment. I would be careful using the washing machine if you have one and the next time you flush the commode watch the shower floor and see if water backs up in there. If so the drains will need to be cleaned out. This is something that you can do only if you have the equipment to do it with. If you live in an apartment call the manager.

Our lab suddenly started holding her head in the air sniffing . Very seriously sniffing. We were sitting in the family room with a 1/2 bath located off the family room. She kept holding her head in the air sniffing like we have never seen her do before.
My husband went into the bathroom and called me in there to show me that on the floor of the shower, there was a black powder type substance all over the shower floor. It looked something had exploded in the drain forcing a black powder to burst out of the drain. What could this be?
Was this powder wet or dry? What did it smell like? Do you have a picture? Maybe labman can answer this one, he has a lab too.