For a general discussion of commonly seen adverse effects and
treatment of NSAID toxicosis, see Over-the-counter Nonsteroidal Anti-inflammatory Drugs.
Etodolac is an indole acetic acid–derivative NSAID labeled
for use in dogs to treat pain and inflammation associated with osteoarthritis.
It is rapidly absorbed orally, with peak serum concentrations seen 2 hr after
dosing. It is primarily eliminated through the bile. The elimination half-life
is 8–12 hr. Etodolac appears to be well tolerated by dogs when used at the
labeled dosage (10–15 mg/kg/day, PO) for 1 yr. With multiple doses, clinical
signs of toxicity such as GI ulcers, vomiting, diarrhea, and weight loss can be
seen at 40 mg/kg. Six of 8 dogs died or became moribund because of GI ulceration
at 80 mg/kg.
Meloxicam is an enolic acid–derivative NSAID approved for
use in dogs and cats for controlling pain and inflammation. Meloxicam is
available as a solution for injection (5 mg/mL) and as an oral suspension. In
cats, it has been approved for use as a single SC injection at 0.3 mg/kg. In
dogs, the recommended initial dosage is 0.2 mg/kg, followed by 0.1 mg/kg, PO.
Meloxicam has a good margin of safety in dogs. Oral administration at 0.1 mg/kg
for 26 weeks was well tolerated in dogs. Some dogs at 0.3 or 0.5 mg/kg, PO, for
42 days have shown clinical signs consistent with NSAID toxicity (vomiting,
diarrhea, renal effects). In cats, the margin of safety appears to be narrow;
extra-label dosing at 0.1–0.2 mg/kg, PO, for a few days has caused adverse
Deracoxib is a coxib COX-2 inhibitor (in vitro) used to
treat osteoarthritis in dogs. It is not approved for use in cats. The
recommended dosage is 1–2 mg/kg/day or 3–4 mg/kg/day as needed for postoperative
pain, not to exceed 7 days of therapy. Oral bioavailability in dogs is > 90%;
the time to peak serum concentration is ~2 hr. In a 14-day study of dogs that
received 10 mg/kg, no clinically observable adverse effects were seen. Dogs that
received 25 mg/kg/day, 50 mg/kg/day, or 100 mg/kg/day for 10–11 days showed
vomiting and melena; no hepatic or renal lesions were seen in these dogs. Dogs
ingesting >100 mg/kg should be aggressively decontaminated and treated with
IV fluids to prevent renal damage.
Piroxicam is an oxicam derivative. It is not approved in
dogs and cats but has been used at 0.3 mg/kg, PO, every other day. Piroxicam in
dogs and people has a long half-life (40 hr and 50 hr, respectively) likely due
to extensive enterohepatic recirculation. The LD50 of
piroxicam in dogs is >700 mg/kg. Adverse GI effects were seen in 18% of dogs
given piroxicam at 0.3 mg/kg/day, PO, for several months.
Diclofenac is a phenylacetic acid derivative structurally
related to meclofenamate sodium and mefenamic acid. After a single injection of
diclofenac sodium at 1 mg/kg in dogs, 35%–40% is excreted in the urine. The
reported oral LD50 of diclofenac sodium in
dogs is 500 mg/kg.
Indomethacin is an indole acetic acid derivative
available as the base and as the sodium trihydrate salt. The drug is
structurally and pharmacologically related to another NSAID, sulindac. The
reported oral LD50 of indomethacin in rats is
12 mg/kg. Administration of indomethacin to dogs at 2 mg/kg for 30 days resulted
in GI ulcers in 60% of dogs and perforation in 20%.
Etodolac, an indole acetic acid derivative, is used for
pain relief, osteoarthritis, and rheumatoid arthritis in people. It is approved
in the USA for use in dogs (>12 mo old) to manage pain and inflammation
associated with osteoarthritis. The suggested canine dosage is 10–15 mg/kg.
Etodolac is well absorbed orally in dogs, with peak plasma concentration seen in
2 hr. It is primarily excreted through bile, and the half-life in dogs is 8-12
hr. In dogs, etodolac at 40 mg/kg/day was associated with GI ulcers, weight
loss, emesis, and local occult blood loss. Dosages of 80 mg/kg/day caused 6 of 8
dogs to die or become moribund because of GI ulceration.
Nabumetone differs from other NSAIDs in that it is
neutral as opposed to acidic. The risk of GI ulcers from nabumetone is
considered less than that of other NSAIDs. Nabumetone is primarily excreted in
the urine in most species. However, in dogs, when nabumetone was administered at
20 mg/kg, only 27% of the dose was found in the urine. The reported oral
LD50 of nabumetone in rats is >2 g/kg. At a dosage
of >300 mg/kg, the lower GI tract and the kidneys were affected in rats,
mice, rabbits, and rhesus monkeys.
Last full review/revision August 2014 by Safdar A. Khan, DVM, MS, PhD, DABVT