Meloxicam is the most widely used non-steroidal anti-inflammatory drug (NSAID) in feline medicine and one of the most effective analgesic and anti-inflammatory agents available to veterinary practitioners. It is also one of the most misunderstood, with significant controversy surrounding its long-term use in cats — particularly in individuals with concurrent renal disease.
This article provides a thorough, evidence-based overview of meloxicam in cats: its mechanism of action, licensed indications, dosing protocols, adverse effect profile, the contentious question of long-term use in cats with chronic kidney disease, and the practical monitoring approach that allows its benefits to be accessed while minimising risk.
Mechanism of Action
Meloxicam is a preferential COX-2 inhibitor — it inhibits cyclooxygenase-2 (COX-2), the inducible isoform responsible for prostaglandin synthesis at sites of inflammation and injury, with relatively greater selectivity than COX-1, the constitutive isoform that maintains homeostatic prostaglandin activity in the stomach, kidneys, and platelets.
By reducing prostaglandin production, meloxicam produces three clinically useful effects: analgesia (by reducing sensitisation of peripheral nociceptors), anti-inflammation (by reducing vascular permeability and leucocyte recruitment), and antipyresis (by resetting the hypothalamic thermostat). Its relative COX-2 selectivity, compared to older non-selective NSAIDs like aspirin, theoretically reduces but does not eliminate gastrointestinal and renal adverse effects.
| Why Cats Are More NSAID-Sensitive Than DogsCats have a genetic deficiency in the glucuronidation enzyme UGT1A6, which is the primary route for eliminating many NSAID metabolites. This means meloxicam and its breakdown products are cleared more slowly in cats than in dogs, narrowing the therapeutic window. Doses safe in dogs can cause toxicity in cats, making correct feline-specific dosing critical. |
Licensed Indications
Meloxicam is licensed in most countries for the following feline indications:
- Post-operative analgesia (single injection): Subcutaneous or intravenous meloxicam 0.3 mg/kg as a single pre- or peri-operative dose is licensed for reducing post-surgical inflammation and pain. This is the original and most tightly licensed indication.
- Acute musculoskeletal pain (short-term oral): Oral meloxicam is licensed in many countries for short-term management of acute musculoskeletal pain in cats, typically for 3 to 5 days at 0.1 mg/kg on day 1 followed by 0.05 mg/kg once daily.
- Chronic musculoskeletal pain (long-term oral): In the European Union and several other regions, oral meloxicam at 0.05 mg/kg or lower once daily is licensed for long-term management of degenerative joint disease and associated chronic pain. This indication is not universally approved and remains a source of ongoing regulatory and clinical debate.
In the United States, the FDA label for Metacam in cats specifies a single injectable dose for post-operative use only. Long-term oral use in cats is considered off-label in the US, though it is widely practised under veterinary supervision.
| US Regulatory NoteIn the United States, the Metacam (meloxicam) label carries a boxed warning stating that repeated use in cats has been associated with acute renal failure and death. Long-term use is not FDA-approved for cats in the US. This does not mean it cannot be prescribed — veterinarians may prescribe off-label with appropriate informed consent — but it means that careful patient selection and monitoring are essential. |
Dosing Protocols
| Indication | Route | Starting Dose | Maintenance Dose | Duration |
| Post-operative analgesia | SC / IV | 0.3 mg/kg single dose | Not applicable | Single injection only |
| Acute pain (short-term) | Oral | 0.1 mg/kg day 1 | 0.05 mg/kg q24h | 3–5 days maximum |
| Chronic pain (long-term) | Oral | 0.05 mg/kg q24h | 0.025–0.05 mg/kg q24h (lowest effective) | Long-term with monitoring |
| Elderly / CKD cats (off-label) | Oral | 0.05 mg/kg q24h or every 48h | 0.025 mg/kg or less, titrated | With enhanced monitoring |
Meloxicam oral solution for cats (0.5 mg/mL) is supplied with a weight-calibrated syringe to minimise dosing errors. Accurate body weight measurement before each prescription refill is essential — underdosing reduces efficacy and overdosing increases toxicity risk.
Adverse Effects
Renal Toxicity
Prostaglandins play a critical homeostatic role in maintaining renal blood flow, particularly when renal perfusion pressure is reduced — during anaesthesia, dehydration, cardiovascular disease, or pre-existing renal disease. NSAID-induced inhibition of renal prostaglandins in these contexts can precipitate acute kidney injury. This is the primary serious adverse effect of meloxicam in cats.
Risk factors for meloxicam-associated nephrotoxicity include:
- Pre-existing chronic kidney disease (any IRIS stage)
- Dehydration or reduced fluid intake
- Concurrent use of diuretics or ACE inhibitors (additive risk)
- Hypotension (e.g., under anaesthesia without adequate fluid support)
- Concurrent use of other nephrotoxic drugs
- Advanced age
Gastrointestinal Effects
Prostaglandins maintain the protective mucous layer of the gastric epithelium and modulate gastric acid secretion. NSAID-mediated COX-1 inhibition can compromise this protection, leading to gastric irritation, ulceration, and haemorrhage. GI adverse effects are less common with meloxicam than with non-selective NSAIDs but remain a real risk, particularly with long-term use or in cats that are fasted or have concurrent GI disease.
Signs of GI toxicity include vomiting, decreased appetite, melaena (black, tarry stools indicating digested blood), and lethargy. Haematemesis (vomiting blood) indicates more serious ulceration.
Hepatotoxicity
Hepatotoxicity is less common than renal or GI adverse effects but has been reported with meloxicam in cats. Liver enzyme elevations (ALT, ALP) on routine monitoring may be the first indication. Significant hepatotoxicity warrants discontinuation and supportive care.
The Long-Term Use Controversy: Meloxicam in Cats with CKD
The most clinically contentious question in feline NSAID pharmacology is whether meloxicam can be safely used long-term in cats with concurrent chronic kidney disease. The answer from current evidence is nuanced.
The concern is straightforward: CKD cats have reduced renal reserve, meaning that additional prostaglandin-dependent renal protection is more important, not less. NSAIDs that suppress this protection could theoretically accelerate CKD progression.
However, two important considerations argue for a more nuanced position. First, undertreated chronic pain — including the musculoskeletal pain from degenerative joint disease that is extremely common in older cats — has its own negative physiological consequences, including stress-axis activation, reduced mobility, anorexia, and reduced quality of life. Second, several published retrospective studies and case series have not demonstrated accelerated CKD progression in cats receiving low-dose oral meloxicam with appropriate monitoring, leading some authors to argue that the risk of withholding adequate pain relief may outweigh the risk of carefully monitored low-dose NSAID therapy.
| Current Clinical Consensus Most feline medicine specialists currently take an individualised risk-benefit approach. Low-dose oral meloxicam (0.025 mg/kg every 24–48 hours) can be considered in IRIS Stage 1–2 CKD cats with significant pain when quality of life is compromised and non-NSAID analgesic options are inadequate, provided: the cat is well-hydrated, not receiving concurrent nephrotoxic drugs, and renal function is monitored every 1–3 months. IRIS Stage 3–4 CKD is generally considered a contraindication. |
Contraindications
- Known hypersensitivity to meloxicam or other NSAIDs
- Pre-existing gastrointestinal ulceration or bleeding
- Significant hepatic disease
- IRIS Stage 3 or 4 CKD (relative contraindication; absolute in severe renal failure)
- Dehydration or conditions predisposing to reduced renal perfusion
- Concurrent use of other NSAIDs, corticosteroids, or anticoagulants
- Pregnancy, lactation, or use in kittens under 6 months
Monitoring Protocol
| Monitoring Parameter | Before Starting | First 1–3 Months | Long-Term (Stable) |
| Body weight | Yes — for dose calculation | Every visit | Every 3–6 months |
| Serum creatinine and SDMA | Yes — establish baseline | Every 4–8 weeks | Every 3 months |
| BUN and electrolytes | Yes | Every 4–8 weeks | Every 3–6 months |
| Urinalysis and USG | Yes | Every 4–8 weeks | Every 3 months |
| ALT and ALP (liver) | Yes | Every 8–12 weeks | Every 6 months |
| Blood pressure | Yes (especially in older cats) | Every 4–8 weeks | Every 3–6 months |
| GI signs (owner-reported) | N/A — client education | Every visit / phone check | Every visit |
Practical Tips for Owners
- Never adjust the dose yourself: The dose calibration for meloxicam in cats is very precise. Do not give more than prescribed if your cat seems in pain — contact your veterinarian.
- Always give with food: Administering meloxicam with a small meal reduces gastric irritation.
- Keep your cat well hydrated: Ensure access to fresh water at all times. Dehydration dramatically increases renal risk. Consider wet food to increase fluid intake.
- Do not miss monitoring appointments: Renal toxicity can develop silently. Blood and urine tests are not optional extras — they are the safety mechanism that makes long-term use responsible.
- Stop immediately and contact your vet if: Your cat stops eating, vomits repeatedly, develops dark stools, becomes lethargic, drinks dramatically more or less than usual, or produces little urine.
Key Takeaways
- Meloxicam is the most effective and most studied NSAID for pain management in cats, with both short-term and (where licensed) long-term indications
- Cats metabolise meloxicam more slowly than dogs — correct feline-specific dosing is essential and errors are clinically significant
- Renal toxicity is the primary serious adverse effect; risk is highest in dehydrated, elderly, and CKD cats
- Long-term use in CKD cats requires a careful individualised risk-benefit assessment and enhanced monitoring frequency
- In the US, long-term oral use is off-label; in the EU, it is licensed for chronic musculoskeletal pain management
- Regular monitoring (renal function, liver enzymes, urinalysis) every 3 months is the standard for cats on long-term meloxicam
References
1. Lascelles BD et al. (2010). Evaluation of a therapeutic diet for feline degenerative joint disease. J Vet Intern Med 24(3):487–95.
2. Gunew MN et al. (2008). Long-term safety, efficacy and palatability of oral meloxicam at 0.01–0.03 mg/kg for treatment of osteoarthritic pain in cats. J Feline Med Surg 10(3):235–41.
3. Sparkes AH et al. (2010). An evidence-based perspective on NSAIDs in cats. J Feline Med Surg 12(7):523–42.
4. Gruen ME et al. (2014). Use of a cardinal signs-based questionnaire to assess degenerative joint disease-associated pain in cats. J Am Vet Med Assoc 245(11):1282–92.
5. Court MH (2013). Feline drug metabolism and disposition. Vet Clin North Am Small Anim Pract 43(5):1039–54.
6. Plumb DC (2018). Plumb’s Veterinary Drug Handbook, 9th ed. Wiley-Blackwell.