[Gpdd] [HEALTH] Smelly urine?

[RundlettDR at aol.com]

Hi!  I have 2 males that are about 2 1/2 years old.  Lately (past  month or 
so) their cage has been getting extremely smelly very quickly.  I  used to be 
able to spot clean daily and thoroughly clean every 6 days, but  lately there's 
been an awful smell by the 3rd day.  I usually use aspen,  changed to 
Carefresh (didn't help - even shorter "smell time" then the aspen)  and back to 
aspen.  I line the bottom of the cage with paper towel prior to  the 
aspen/carefresh.  The towels are extremely wet when I change  them.  I'm wondering 2 things 
and would like some feedback. 1)   Piggies seem fine - playing, talking, 
eating up a storm.  Any reason for  health concern for the smell?   2)  Has anyone 
ever put cat  litter under the paper towel/aspen to absorb smell?  I read it 
in a Guinea  Pig book, but have never noticed it mentioned on the gpdd site.  
Thanks so  much for your info!
Donna, Jazzy & Skwirt