drooling and facial spasms due to cat urine??

Mykilo, when coming into contact with cat urine, will drool, pools of drool, and his mouth and top of head seem to spasm uncontrollably, like he's having a seizure, he looks almost like he's convulsing, we thought it was at first, female dog urine, or scent etc.. but later found it to be the cat's urine that makes him wierd out, does anyone else have this similar characteristics with there dog and if so ,why do they do this?

 

Ive never had that problem with any of my 4. Although they will fight over the "treasures" they find in the litter box.

 

when my dog comes in contact with any kind of urine he does this, he's been doing this forever, never had any problems with it.

 

bud guy, do you know perhaps why they do this, my dog goes into a transe like state, it bugs me.