Journal Scan: Does storage in formalin affect urolith evaluation?
What they did
What they found
A portion of every struvite urolith was transformed into newberyite after exposure to formalin. Newberyite is considered an in vitro artifact and not a biogenic material. Researchers also found that three of the 10 ammonium urate uroliths dissolved when placed in formalin. The mineral composition of all other uroliths was unchanged.
Albasan H, Osborne CA, Lulich JP, et al. Effects of storage in formalin on composition of canine and feline uroliths. J Am Vet Med Assoc 2012; 241(12):1613-1616.
Link to abstract: http://avmajournals.avma.org/doi/abs/10.2460/javma.241.12.1613