A 6-month old female domestic shorthair
cat was submitted to the WSVL for postmortem examination.
Within
the previous two weeks the
cat was spayed and developed an upper respiratory infection.
The
cat received
multiple oral doses of the nonsteroidal anti-inflammatory
drug (NSAIDs) meloxicam (e.g.,
Metacam®) over a
four-day period. Three days later the
cat was presented to the veterinary clinic obtunded and
dehydrated. Clinical
chemistry revealed elevated total protein, amylase, BUN,
creatinine, and phosphorus. Blood glucose was 314
mg/dl. Sodium was low and potassium high.
At necropsy, bilateral pallor and slight yellow
discoloration were noted in the renal papillae. Microscopically,
extensive acute coagulative necrosis compatible with renal
papillary necrosis was the lesion in these areas of
pallor.
The pale area demarcated by arrowheads
demonstrates acute necrosis
A syndrome of analgesic nephropathy with papillary
necrosis is well recognized in humans. Renal lesions are
believed to reflect the combined effects of inadequate
water intake (dehydration) and failure of vasoregulation in
the
kidney leading to ischemia. Similar acute syndromes of renal
failure due to papillary necrosis are reported in
animals. NSAIDs inhibit cyclooxygenase (COX) enzymes
involved in prostaglandin synthesis and prostaglandins
are involved in regulating vascular tone. This is mainly
an effect of COX-I inhibition. Newer NSAIDs such as
meloxicam primarily inhibit the COX-II enzyme and
supposedly have less severe side effects. The lesions and
history of meloxicam administration in the
cat may indicate the need for caution in administering the
drug and
assurance of adequate hydration in this species
Dr. Don Montgomery
3 February 2005
(7-17-06)
A few weeks ago, the Silver Persian of a friend of mind died
after minor dental surgery. She was only 6 years old and in
absolutely perfect health. The vet suspected an adverse reaction
to Metacam, which is a relatively new painkiller that
veterinarians have started prescribing for cats. An autopsy
confirmed that it was the Metacam that caused the death.
My friend, through web searches, found that so many cats have
been dying from this drug, frequently after dental procedures,
that there is a whole website devoted to postings from people
about their experience with losing their perfectly healthy kitty
due to Metacam. (See the link to these postings at the end of
this article.)
And I myself have had a freightening first-hand experience with
this drug. Just a few weeks prior to receiving my friend's news,
my veterinarian (who is a very, very good veterinarian, by the
way) prescribed Metacam for my kitty, George (rescued in 2005
from Persian & Hinalayan Cat Rescue!) who has a bit of
arthritis. The vet prescribed 2 drops in Georgie's food every 3
days. After the second dose, Georgie started throwing up a
little bit almost every night. I took him to the vet right away
and we (vet and I) thought it might be due to his developing a
sensitivity to the food we give him. But changing food didn't
help. Then my friend told me what happened with his kitty due to
Metacam! I immediately stopped the medication and after a few
days of being overdue for his next dose, he quit vomiting and
hasn't done so since.
Of course, I told my veterinarian. She had not been advised by
the drug representative that there were any problems that were
occuring due to the Metacam. I am fortunate that my vet was so
careful to give Georgie a low dose.
