Rimadyl for Dogs: Side Effects in Older Dogs, What's Normal vs Concerning

Your older dog was just prescribed Rimadyl for arthritis pain, and you're worried about side effects you've heard about. Here's exactly what's normal vs dangerous, special considerations for senior dogs, and how to keep your dog safe while getting effective pain relief.

What Is Rimadyl?

Rimadyl is a non-steroidal anti-inflammatory drug (NSAID) approved for dogs. It reduces pain and inflammation by blocking enzymes involved in the inflammatory process. Unlike steroids such as prednisone, Rimadyl specifically targets pain pathways and is used mostly for joint and post-surgical pain.

Rimadyl (generic name: carprofen) is a non-steroidal anti-inflammatory drug (NSAID) that's FDA-approved specifically for dogs. It comes in chewable tablets, caplets, or injectable form and is commonly prescribed for arthritis and post-surgical pain.

Why Do Vets Prescribe Rimadyl?

Rimadyl is most commonly prescribed for:

• • Osteoarthritis: to relieve pain and stiffness in aging or arthritic dogs
• • Post-surgical pain: often given after spays, neuters, or orthopedic procedures
• • Musculoskeletal injuries: sprains, strains, or soft tissue injuries

Some dogs take Rimadyl short-term, while others may use it long-term to manage chronic arthritis. For dogs with severe pain that may also require anti-inflammatory treatment, veterinarians must carefully choose between NSAIDs like Rimadyl and corticosteroids such as prednisone, as they cannot be used together safely.

Common Side Effects of Rimadyl in Dogs

Most dogs tolerate Rimadyl well, but as with all NSAIDs, there are risks. Common side effects include:

• • Vomiting or diarrhea
• • Loss of appetite
• • Lethargy
• • Black or tarry stools (a sign of stomach bleeding)

Serious side effects are less common but include stomach ulcers, liver enzyme elevations, kidney issues, and gastrointestinal bleeding. These are more likely in older dogs or those on long-term treatment.

Rimadyl Side Effects in Older Dogs: What to Know

Senior dogs (typically 7+ years) can safely use Rimadyl, but they're at higher risk for side effects than younger dogs. Here's why and what to watch for:

Because of these factors, most vets require baseline bloodwork before starting Rimadyl in senior dogs, then recheck every 3-6 months to catch any problems early.

Monitoring Requirements for Senior Dogs on Rimadyl

What vets check in senior dog bloodwork

• • ALT, ALP (liver enzymes) — watch for increases above baseline (see our dog ALT levels guide)
• • BUN, Creatinine (kidney function) — even small increases matter in seniors
• • Red blood cells — check for anemia from GI bleeding
• • Platelets — NSAIDs can affect clotting in rare cases

Alternatives to Rimadyl for Older Dogs

If your senior dog doesn't tolerate Rimadyl well, alternatives include:

• • Gabapentin - Nerve pain medication, can be used with Rimadyl
• • Other NSAIDs (Galliprant, Meloxicam) - May be better tolerated in some dogs
• • Adequan injections - Joint support for arthritis
• • Physical therapy and weight management - Non-drug pain relief options

Safety and Monitoring

Your vet will usually recommend baseline bloodwork before starting Rimadyl, especially for older dogs, and periodic rechecks to monitor liver and kidney values.

What to Watch for at Home

Call your vet if you notice vomiting, diarrhea, loss of appetite, black stools, jaundice (yellow gums/eyes), or increased drinking and urination while your dog is on Rimadyl. Stopping the drug early and switching to another pain management option may prevent more serious complications.

Typical Dosage and Administration

The typical Rimadyl dose is 2-4 mg per kg of body weight daily, given once or twice daily with food. It can be used short-term (days to weeks) for acute pain or long-term for chronic conditions like arthritis. Always follow your veterinarian's specific dosing instructions.

Related Reading

• • Prednisone for Dogs – sometimes used as an alternative anti-inflammatory medication
• • Understanding CBC Results – helpful if your vet runs bloodwork while monitoring Rimadyl use
• • High ALT in Dogs – liver monitoring is important with NSAID use
• • Gabapentin for Dogs – alternative pain management option that can be used with Rimadyl

Frequently Asked Questions

Sources

• VCA Animal Hospitals - Carprofen (Rimadyl)
• American Kennel Club - Rimadyl for Dogs