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'''Uric acid''' is the main form of nitrogenous waste with lesser amounts of ammonia and urea depending on the species, the natural environment and degree of water conservation required. Uric acid is excreted by tubular secretion rather than urea by glomerular filtration.

'''Uric acid''' is the main form of nitrogenous waste with lesser amounts of ammonia and urea depending on the species, the natural environment and degree of water conservation required. Uric acid is excreted by tubular secretion rather than urea by glomerular filtration.

Most lizards have a '''urinary bladder''' where the urine may be modified. Urinalysis may therefore not indicate renal function. The bladder is present in most lizards and helps water retention. It connects to the cloaca by a short urethra. Reflux urine is concentrated.

Most lizards have a '''urinary bladder''' where the urine may be modified. Urinalysis may therefore not indicate renal function. A thin-walled bladder is present in most lizards and helps water retention. When absent, urine is stored in the distal colon. It connects to the cloaca by a short urethra which means that urine waste flows from the kidney through the ureter into the urodeum of the cloaca before entering the bladder (or colon for species lacking a bladder), resulting in non-sterile urine, unlike mammals.  

==References==

==References==

* Mader, D.R. (2005). ''Reptile Medicine and Surgery''. Saunders. pp. 1264. ISBN 072169327X

* Mader, D.R. (2005). ''Reptile Medicine and Surgery''. Saunders. pp. 1264. ISBN 072169327X