Have Reptile Veterinary Questions? Ask a Reptile Expert.
My name is ***** ***** I have been a Vet tech for 30+ years with special interest in Reptiles and a Reptile rescue.
It sounds like your Leo has aspirated the water into the lungs causing aspiration Pneumonia. This will need to be addressed by a Herp Vet asap. They will start an Antibiotic and give medication to assist with breathing. If you supply a State, I can locate some Herp Vets for you.
He may have been ill prior to the soak, but from what you have described he did aspirate water and that is why the gaping when breathing. Being over on the back compresses the lungs, and made it easier to inhale the water and aspirate it into the lungs. I did not see a Herp Vet right in Liverpool, but have a list of Herp Vets avalable to treat the Leo:
The constant gaping is a sign of Respiratory distress, and when we see that we have to recommend a Herp Vet.
If you are using D3 that can cause the problem. We have found D3 can have adverse Neurological effects on Reptiles. I see you are using both with and without D3, That is the one issue that can cause it. The other we see with Metabolic Bone Disease, can cause it, or a Vitamin Difiency. The Vet will be able to fully determine the cause.