Rimadyl: Often Used to Treat Arthritis in Dogs, it is Not Without Risks

The signs of arthritis in dogs are similar to those in humans. Your dog will move stiffly or show lameness. He might be more subdued and be less likely to run, jump, and will show difficulty when walking or using stairs. Historically, buffered aspirin has been used to treat dogs with arthritis. but drugs used to treat humans are not absorbed well by dogs so something better was needed for the canine metabolism. Rimadyl was developed by Pfizer Animal Health of Exton, PA and has been in use since 1997.

What is Rimadyl?
Rimadyl® (Generic name: Carprofen also known as Zenecarp or Norocarp) is used to treat Osteoarthritis and Post-Surgical Pain. The drug is available by veterinary prescription only. It is available in caplet and chewable tablet, or can be administered via injection by your veterinarian. It has not been approved for use for any other animals except dogs.

Do you want your dog's arthritis treated with Rimadyl?

Perhaps. It is reported that a dog's recovery from pain can be quite dramatic. Who wouldn't want his beloved pet/best friend to experience less pain? According to Pfizer, less than 1% of dogs on the drug will suffer a negative reaction.

The Senior Dog Project (http://www.srdogs.com) is an organization that advocates the adoption, rescue and care of older dogs. It acts as a public forum for Rimadyl information, and the stories of beloved pets suffering and dieing after being given Rimadyl are frequent and troubling. There are also reports that liver toxicity occur with greater frequency in Labrador Retrievers than in any other breed.

Here is a set of symptoms of a Rimadyl reaction reported by the site:
1. loss of appetite
2. change in drinking habits (refusal to drink or increased water consumption)
3. unusual pattern of urination, blood in the urine, sweet-smelling urine, an overabundance of urine, urine accidents in the house
4. vomiting
5. diarrhea
6. black, tarry stools or flecks of blood in the vomit
7. lethargy, drowsiness, hyperactivity, restlessness, aggressiveness
8. staggering, stumbling, weakness or partial paralysis, full paralysis, seizures, dizziness, loss of balance
9. jaundice (yellowing of the skin, mucus membranes and whites of the eyes)

Pfizer recommends that before starting a Rimadyl regimen that the following be done:

1. Complete history and physical exam before dispensing NSAID.
2. Definitive diagnosis for NSAID therapy so therapeutic response can be monitored.
3. Baseline and repeat laboratory data should be considered on a case-by-case basis.
4. Follow-up communication with owners.
5. Inform owners of clinical signs of drug intolerance.
6. Repeat laboratory tests before refilling prescriptions, especially in patients with history of gastrointestinal signs, renal and hepatic disease.
7. Recheck evaluations after 3-4 weeks, then 3-6 months thereafter in patients requiring chronic NSAID therapy.

Rimadyl should not be taken with other NSAID's, corticosteroids, phenobarbital, medications for cardiac disease such as ACE inhibitors and fireside, and drugs that bind to protein in the blood.

Conclusions

There are many veterinarians who have treated dogs with Rimadyl for over a decade without a known mishap. Make sure that your vet is aware of the issues surrounding this treatment because some are unaware of the Rimadyl issues. At the very least, dog owners should receive a "Client Information Sheet" and read it thoroughly before allowing their dog to be treated with Rimadyl. Be aware of of the contraindications, and watch your dog for any signs of toxicity or side effects. Call your veterinarian immediately if you have any concerns.