From the 2006 Study from European Medicines Agency

Tolerance study in cats on meloxicam (Metacam) at dose levels of 0.3 and 0.6 mg/kg body
weight given as single subcutaneous injections followed by oral treatment of the same dosages
for 9 consecutive days

Twelve adult cats, six males and six females, were randomly allocated to three equal groups. Group 1
received a single s.c. injection of placebo on day 0, followed by daily oral placebo dosing for 8 days.

Groups 2 and 3 were given s.c. injections of 0.3 and 0.6 mg/kg b.w., respectively, on day 0 followed by oral administration of the same doses for 8 days.

The study was originally designed for a treatment period of 10 days, but 2 cats, one in group 2 and one in group 3, were found dead on day 8.
These animals had shown depressed demeanour and reduced appetite since days 3-4 of the study.

After 8 days of treatment depressed demeanour and
gastrointestinal signs occurred in two cats in group 2 and in three cats in group 3. On day 9 all
meloxicam treated animals showed clinical signs (animal more subdued than normal), the study was
terminated and all surviving animals were necropsied.

Pyloric/duodenal ulceration and peritonitis were
found in two cats of the highest dose group. Signs of peritonitis were found also in the other two cats
of this group, but the pylorus/pyloric duodenal junction was not investigated histologically in these
animals. Minimal signs of peritonitis occurred also in two animals treated with 0.3 mg/kg b.w. over 8
to 9 days. Granulomatous inflammation of the intestinal wall was found in one animal. Feline
Infectious Peritonitis was excluded by serological investigation.
Clinical signs of NSAID toxicity were a depressed demeanour and gastrointestinal signs.
Pathohistological pyloric/duodenal ulceration and peritonitis were described. No treatment related
haematological or blood chemical changes were found. Faeces was tested for the presence of occult
blood during the study, and positive samples were found in all groups (including placebo) at all time
points and also pretreatment. Similar experiences were recorded in earlier dog studies, and the
conclusion was drawn that commercial kits for the testing of blood in faeces are not reliable. The
findings of the study were that repeated administration of meloxicam at the doses 0.3 and 0.6 mg/kg
b.w. followed by oral administration of the same doses for 8 days can cause pyloric and duodenal
ulceration and that the risk/benefit needed to be evaluated at lower dose levels.