Never had this problem with a bierdie but i know with monitors usually means that the humidity is to low.... maybe he is to dehydrated in his cage.... they are desert animals but still like some humidity.... dont know if that helps but just some thought....
-----
Tom
1.2.0 Leopard Gecko (dot, spot, casper)
0.0.1 California King Snake (booboo)
0.1.0 Sulcata Tortoise (tank)
0.0.2 Russian Tortoise (tito and lulu)
0.0.2 Red Ear Sliders (bernie and ernie)
0.0.3 Painted Turtles (larry, curly and moe)
0.0.1 Western Soft shell (Squirt)
2.2.0 Bearded Dragon (marshmellow,Bubba,Sparkles,Alfredo )
0.0.1 Savannah Monitor (beef)
1.0.0 Peachfront Conure (kermit)
0.1.0 Love Bird ( KIKI )
1.1.0 Dog (layla and Rosco)
2.1.0 Crazy Cats (babe, sabastian, tinkerbell)
0.1.0 Lion Head Rabbit (daisy)
0.1.2 Ferret (jordan RIP, Cosmo and Izzy)
0.2.0 Guinea Pigs (lilly and petunia)
0.0.1 White Tree Frog (dumpy jr.)
0.0.2 Fire Belly Newts (spork and blaze)
0.0.1 Fire Belly Toad (ferdinan)
0.0.1 Red Spotted Newt ( red)
0.0.2 Bull Frogs (goliath and tubby)
0.0.1 Spectacled caiman (wilbert)
0.0.3 Green Anoles
1.0.0 Bahama Anole
0.0.1 Giant Millipede
Lots Of Fish