Hello,
Ok, so how long have you used the Reptiglo 10 for him? That particular light has only been around for maybe 1 1/2 years at the most. You probably used the Reptiglo 8 previously, is this correct?
The Reptiglo 10 is not a good light, unfortunately. The usable UVB emissions are poor. This light emits low wavelength frequency of UVB which is within the range of UVC. The light does not have favorable wavelength for D3 synthesis as well which means he is unable to process calcium, properly. I highly recommend getting a different
UVB light. I would get the Reptisun 10 flourescent tube bulb, for starters.
He needs calcium, even at his age, at least 2-3 times per week.
My thought are initially, is that he is hypocalcemic & strained to go to the bathroom, & it caused some bleeding. Did he prolapse?
He also could have an elevated worm or parasite level as well, which could cause bleeding, too.
Have his stools always looked ok, have they ever had any sand in them? What have you been feeding him then, if you have never fed crickets or worms? How many did you feed him? Could he have been slightly impacted with sand? Sand can build up in their GI tract over years, even in adults. While it doesn't impact & harden like the calcium based sands do, it can still build up on the intestinal lining causing the microvilli to become damaged & the GI tract to become irritated & cause ulcers or sores that could bleed which are raw. Perhaps he has colitis or peritonitis. So those are things you can discuss with the vet, also.
While the Reptiglo 8 is an ok light, it does not put out large amounts of UVB. So, combined with using that weak light for years, & not giving much calcium for him, his body has begun to show weakness. Reptiles do not always show weakness immediately. He has good genes, being a german giant so that is probably one reason he has not shown any problems until now.
What I recommend is getting him to the vet to get a bloodtest. Get them to do an ionized calcium test which will further determine his 25 hydroxy levels that show bone density & absorption. Also, getting x-rays would be a good idea also, to see what the bone density looks like. Also, the blood tests will reveal whether or not he is having liver or renal issues as well.
For tonight, try to keep him calm, if you can. Will he take any oral fluids from you via a plastic dropper?
Tracie