# Tolfenamic Acid: veterinary dose and monograph

> Tolfenamic Acid is a veterinary anti-inflammatory drug. Fenamate NSAID with potent COX-2 inhibition and dual prostaglandin-receptor antagonism. Indications include mastitis, pneumonia, metritis-associated pain & inflammation; musculoskeletal pain — arthritis, laminitis, sprains; postoperative analgesia. This monograph lists 7 reference doses for dogs, cats, cattle, pigs and buffalo, each with route, frequency and source, plus meat and milk withdrawal periods for food animals.

Source: https://vetmasterji.com/drugs/tolfenamic-acid · Last reviewed: 2026-10-01

## At a glance

- **Drug class:** Anti-inflammatory
- **Also known as:** Maxxtol, Maxxtol-XP, Tolfedine
- **Species with doses:** Dogs, Cats, Cattle, Pigs and Buffalo
- **General dose range:** 2–4 mg/kg IM q24–48h — check the species tables for the indication
- **Routes:** IM, IV, PO
- **Last reviewed:** 1 October 2026

## Indications

- Mastitis, pneumonia, metritis-associated pain & inflammation
- Musculoskeletal pain — arthritis, laminitis, sprains
- Postoperative analgesia
- Bovine endotoxic shock support

## Tolfenamic Acid dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

### Dogs

*Tolfenamic Acid doses for dogs*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Post-operative / chronic pain | 4 mg/kg | PO | q24h | day 1; then 4 mg/kg q24h × 3–5 days |

- Post-operative / chronic pain: Plumb’s p.1132: acute pain 4 mg/kg SC, IM or PO once daily for 3–5 days (injection for the first dose only); chronic pain 4 mg/kg PO once daily for 3–5 consecutive days per week (Dowling); label — 4 mg/kg SC/IM then 4 mg/kg PO daily for 2–4 days, repeatable weekly. Not in Papich 5e.

### Cats

*Tolfenamic Acid doses for cats*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| Acute pain | 4 mg/kg | PO | q24h | 3–5 days |

- Acute pain: Plumb’s p.1132 (Dowling 2000; Tolfedine label, Canada): cats 4 mg/kg SC, IM or PO once daily for 3–5 days; the injection is suggested for the first dose only. Ensure hydration — NSAID renal risk in cats.

### Cattle

*Tolfenamic Acid doses for cattle*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Anti-inflammatory single shot | 4 mg/kg | IM | once | single dose | 10d slaughter / 12h milk |
| Pneumonia (IM, may repeat once) | 2 mg/kg | IM | once; may repeat once after 48 h | — | 10d slaughter / 12h milk |
| Acute mastitis (single IV) | 4 mg/kg | IV | once | — | 4d slaughter / 12h milk |

- Anti-inflammatory single shot: Single 4 mg/kg IM shot per Indian product label (Maxxtol, Intas). Plumb’s p.1133 (Australian registration) instead gives 2 mg/kg IM high in the neck for pneumonia and 4 mg/kg as a single IV injection for mastitis; meat withdrawal 10 days after IM, 4 days after IV; milk 12 hours. Always follow the label of the product used.
- Pneumonia (IM, may repeat once): Plumb’s p.1133 (Tolfejec, Australian registration): 2 mg/kg IM high in the side of the neck; may be repeated ONCE after 48 hours. Meat withdrawal 10 days (IM); milk 12 hours.
- Acute mastitis (single IV): Plumb’s p.1133 (Tolfejec, Australian registration): 4 mg/kg as a single intravenous injection for acute mastitis. Meat withdrawal 4 days after IV; milk 12 hours (one milking).

### Horses

*Tolfenamic Acid doses for horses*

| Indication | Dose | Route | Frequency | Duration |
| --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — |

- No reference dose for this species: The previous 2 mg/kg IV horse row had no source; Plumb’s 10e (pp.1254–1256) gives no equine tolfenamic acid dose and Papich has no monograph.

### Goats

*Tolfenamic Acid doses for goats*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — |

- No reference dose for this species: The previous 2 mg/kg IM goat row had no source; Plumb’s 10e (pp.1254–1256) gives tolfenamic acid doses only for dogs, cats, cattle and pigs, and Papich has no monograph.

### Sheep

*Tolfenamic Acid doses for sheep*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| No reference dose for this species | Not established in Papich 5e or Plumb’s 10e — do not extrapolate from another species | — | — | — | — |

- No reference dose for this species: The previous 2 mg/kg IM sheep row had no source; Plumb’s 10e (pp.1254–1256) gives tolfenamic acid doses only for dogs, cats, cattle and pigs, and Papich has no monograph.

### Pigs

*Tolfenamic Acid doses for pigs*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Lameness / MMA adjunct | 2 mg/kg | IM | once | — | 6d slaughter |

- Lameness / MMA adjunct: Plumb's p.1133 (Tolfejec, Troy Labs Australia registration): as an aid in metritis-mastitis-agalactia in pigs, 2 mg/kg IM once; meat withdrawal 6 days.

### Buffalo

*Tolfenamic Acid doses for buffalo*

| Indication | Dose | Route | Frequency | Duration | Withdrawal |
| --- | --- | --- | --- | --- | --- |
| Mastitis / metritis / BRD adjunct / fever | 2–4 mg/kg | IM | once (repeat 2 mg/kg q48h) | — | Withdrawal NOT established — treat as extra-label |

- Mastitis / metritis / BRD adjunct / fever: Maxxtol range labels buffalo with cattle: 4 mg/kg single IM shot (48–72 h effect), or 2 mg/kg IV/IM q48h. Widely used in buffalo for post-calving inflammation and mastitis. Label-sourced; Plumb’s gives cattle 2 mg/kg IM (may repeat once after 48 h) or 4 mg/kg IV once (Australian registration). Follow the local label withdrawal.

## Contraindications

GI ulceration. Renal / hepatic insufficiency. Dehydration. Avoid in cats (limited safety data). Do NOT combine with other NSAIDs or corticosteroids.

## Species-specific warnings

> **Caution:** Cattle: Standard cattle NSAID. 4 mg/kg IM/IV single shot. 7 d slaughter / 24 h milk (Indian label).

> **Caution:** Goats: 2 mg/kg IM single — well tolerated.

> **Caution:** Sheep: 2 mg/kg IM single.

> **Caution:** Pigs: 2 mg/kg IM for lameness, MMA syndrome adjunct.

> **Caution:** Horses: 2 mg/kg IV single. Right dorsal colitis risk with chronic use — limit to 5–7 days.

> **Caution:** Dogs: 4 mg/kg PO daily × 3–5 days for post-op pain. Wide safety margin; not commonly used in small-animal practice outside the EU.

> **Caution:** Cats: NOT used in cats — limited safety data. Use meloxicam single peri-op dose or robenacoxib instead.

## Adverse effects

- GI upset / inappetence
- Renal injury in dehydrated animals
- Local IM injection-site reaction

## Drug interactions

- Other NSAIDs (meloxicam, flunixin, ketoprofen, aspirin): additive GI ulceration / renal toxicity — DO NOT stack
- Corticosteroids (dexamethasone): synergistic GI ulceration — avoid concurrent
- Aminoglycosides / cyclosporine / amphotericin B: additive nephrotoxicity in dehydrated patients
- Furosemide / loop diuretics: blunted diuretic effect + additive renal hypoperfusion
- ACE inhibitors: blunted antihypertensive effect; additive renal risk
- Anticoagulants (warfarin, heparin): increased bleeding risk
- Highly protein-bound — may displace other protein-bound drugs (warfarin, sulfonamides)

## Pregnancy and lactation

AVOID in late pregnancy — NSAIDs can cause premature closure of fetal ductus arteriosus and delay parturition. Single peri-partum dose for post-calving mastitis / metritis is widely used despite this caveat. Limited canine pregnancy data — avoid.

## Monitoring

- Hydration status BEFORE every dose — never give to dehydrated animals
- Renal function (BUN, creatinine) on prolonged use
- GI signs: anorexia, melaena, colic — discontinue at first sign
- Cattle withdrawal: 7 d slaughter / 24 h milk (Indian label; verify per jurisdiction)
- Injection-site for sterile abscess (deep IM, rotate sites)
- Concurrent NSAID / steroid review — never stack

## Toxicity and overdose

GI ulceration with chronic dosing (especially in dehydrated patients). Renal toxicity in hypoperfusion / pre-existing CKD. Hepatic enzyme elevation. Cats: NOT used (limited safety data). Horses: caution — like all NSAIDs, right dorsal colitis with chronic use. Injection-site reactions (sterile abscess, tissue irritation — deep IM mandatory). At label dose in healthy adult cattle, very wide therapeutic margin.

Management: Decontamination if oral overdose <2 h: induce emesis (small animals only), activated charcoal. Aggressive IV fluid diuresis × 48–72 h. GI protection: misoprostol 2–5 µg/kg PO q8h (small animals) + omeprazole + sucralfate. Monitor renal function (BUN, creatinine), CBC, total protein daily for 5 days. Discontinue any other NSAID / nephrotoxin.

## Clinical pearls

- Cattle single shot at 4 mg/kg IM/IV: 48–72 h of anti-inflammatory effect — convenient for mastitis, foot rot, calving inflammation
- Bovine acute coliform mastitis: 4 mg/kg IV single dose — anti-endotoxic similar to flunixin
- Bovine post-calving / retained placenta: 2 mg/kg IM single — reduces inflammation, helps appetite return
- Equine musculoskeletal pain: 2 mg/kg IV single dose; chronic use avoided (right dorsal colitis risk)
- Canine post-op pain: 4 mg/kg PO day 1 then daily × 3–5 days — alternative to carprofen / meloxicam
- Topical Maxxtol Top Gel: laminitis, arthritis, traumatic mastitis — apply 2–3× daily
- Cats: NOT used — limited feline safety data; use meloxicam / robenacoxib instead
- NEVER stack with another NSAID or steroid — GI perforation / AKI risk

## Mechanism of action

Fenamate (anthranilic acid) NSAID. Dual mechanism: inhibits cyclooxygenase (COX, with preferential COX-2 inhibition at therapeutic doses) AND blocks prostaglandin receptors directly — unique among NSAIDs. The dual mechanism extends duration of effect (single 4 mg/kg shot in cattle works for 48–72 h). Anti-inflammatory, analgesic, antipyretic, anti-endotoxic. Widely used in cattle for mastitis, foot rot, calving inflammation, BRD adjunct.

## Formulations and products

- Maxxtol Inj. 40 mg/mL (Intas, 30/100 mL)
- Maxxtol-XP 80 mg/mL (Intas, 20/100 mL)
- Maxxtol bolus 500 mg (Intas)
- Maxxtol Top Gel 6 % w/w (Intas, 30 g tube)
- Maxxtol Inj. (Intas (Neovet)) — 40 mg/mL, Injection
- Maxxtol-XP (Intas (Neovet)) — 80 mg/mL, Concentrated injection
- Maxxtol Bolus (Intas (Neovet)) — 500 mg, Oral bolus
- Maxxtol Top Gel (Intas (Neovet)) — Tolfenamic 6 % + Methyl salicylate + Menthol, Topical gel

## Storage

Injection: 15–25 °C, protect from light. Bolus / tablet: 15–30 °C, dry. Topical gel: 15–25 °C. Multidose vial: discard 28 days after broaching.

## Before you use this dose

> **Caution:** Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

## Other anti-inflammatory drugs

- [Phenylbutazone](https://vetmasterji.com/drugs/phenylbutazone)
- [Piroxicam](https://vetmasterji.com/drugs/piroxicam)
- [Prednisolone](https://vetmasterji.com/drugs/prednisolone)
- [Robenacoxib](https://vetmasterji.com/drugs/robenacoxib)

## Frequently asked questions

### What is the dose of Tolfenamic Acid for dogs?

Reference doses for Tolfenamic Acid in dogs: 4 mg/kg PO q24h for day 1; then 4 mg/kg q24h × 3–5 days (Post-operative / chronic pain). Confirm against the label and the patient before use.

### What is the dose of Tolfenamic Acid for cats?

Reference doses for Tolfenamic Acid in cats: 4 mg/kg PO q24h for 3–5 days (Acute pain). Confirm against the label and the patient before use.

### What is the dose of Tolfenamic Acid for cattle?

Reference doses for Tolfenamic Acid in cattle: 4 mg/kg IM once for single dose (Anti-inflammatory single shot); 2 mg/kg IM once; may repeat once after 48 h (Pneumonia (IM, may repeat once)); 4 mg/kg IV once (Acute mastitis (single IV)). Confirm against the label and the patient before use.

### What is the withdrawal period for Tolfenamic Acid?

Cattle, IM (Anti-inflammatory single shot): 10d slaughter / 12h milk; Cattle, IM (Pneumonia (IM, may repeat once)): 10d slaughter / 12h milk; Cattle, IV (Acute mastitis (single IV)): 4d slaughter / 12h milk; Pigs, IM (Lameness / MMA adjunct): 6d slaughter; Buffalo, IM (Mastitis / metritis / BRD adjunct / fever): Withdrawal NOT established — treat as extra-label. Follow the product label and national regulations where they differ.

### When should Tolfenamic Acid not be used?

GI ulceration. Renal / hepatic insufficiency. Dehydration. Avoid in cats (limited safety data). Do NOT combine with other NSAIDs or corticosteroids.

### What are the side effects of Tolfenamic Acid in animals?

GI upset / inappetence; Renal injury in dehydrated animals; Local IM injection-site reaction.

## Sources

- Intas Animal Health catalogue · Maxxtol range
- Plumb's Veterinary Drug Handbook
- Papich, Papich Handbook of Veterinary Drugs, 5th edition

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VetMasterJi is a clinical decision-support and education platform for veterinary professionals and students. It does not provide veterinary advice, diagnosis or treatment for specific animals. All drug doses, calculators and differentials are references that must be independently verified before clinical use; the attending registered veterinarian remains solely responsible for every clinical decision.