In the distal tubules or collecting
ducts of sick and dead animals specific polarizable crystals
were present. In some animals chronic histological changes
characterized by interstitial fibrosis and inflammation
were found. In cats after intake of feed contaminated with
melamine and cyanuric acid, clinical symptoms such as a
refusal to eat, vomiting, polyuria, excessive thirst and lethargy
were recorded. Histological research of kidney samples
from these cats found intratubular crystalluria, tubular
necrosis with degeneration and subcapsular perivascular
inflammation with sysmptoms of perivascular fibroplasia
or fibrosis and inflammation with intravascular fibrinous
thrombosis. Toxicological analyses found the presence
of melamine and cyanuric acid in the samples of cat feed,
in vomitus, in urine and in the kidneys (Puschner et al.,
2007). Clinical observations of acute renal failure in cats
and dogs were connected with the intake of feed in which
wheat gluten originating from China was used. Analyses of
feed revealed the presence of simple triazine compounds,
esp. melamine and cyanuric acid, together with lower