Dog can't move - Answered by Dr. Van Lienden

[zoya]

He was fine last night...Then this morning we went out to feed him and he couldn't move his front or back legs..He was breathing fine and had tried to drag himself .
His legs just kind of go straight out.
We have had frogs in the yard, and often find black widow spiders and I have killed those black caterpillars with the spikey backs.
Could any of these things have cause him to be paralyzed?
I am soo worried...He can't even get up to go to the bathroom...and he is a lARGE dog...