Bismuth Subsalicylate
Bismuth subsalicylate
Also known as: Pepto-Bismol · Kaopectate · Bismu-kote · Bismupaste · Bismatrol · Corrective Suspension · PalaBIS · BSS · basic bismuth salicylate · bismuth oxysalicylate · bismuthi subsalicylas
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For acute diarrhea | 1 mL per 5 kg of body weight | PO | 3 times a day | should probably not exceed 5 days of therapy | 🌎 NA |
| For acute diarrhea | 0.25 mL/kg up to 2 mL/kg | PO | q4-6h (0.25 mL/kg) or q6-8h (2 mL/kg) | — | 🌎 NA |
| For treating Helicobacter gastritis infections (triple therapy) | 0.22 mL/kg | PO | q4-6h | 3 weeks | 🌎 NA |
| For treating Helicobacter gastritis infections (triple therapy) | 262 mg tablets given based upon body weight (<5kg = 0.25 tablet; 5-9.9 kg = 0.5 tablet; 10-24.9kg = 1 tablet; >25kg = 2 tablets) | PO | q12h | 2 weeks | 🌎 NA |
| As a gastroprotectant/coating agent in the adjunctive treatment of uremic gastritis | 2 mL/kg | PO | q6-8h | — | 🌎 NA |
- For acute diarrhea: Dose based on 17.5 mg/mL liquid
- For acute diarrhea: Pepto-Bismol
- For treating Helicobacter gastritis infections (triple therapy): Given with Metronidazole 15.4 mg/kg q8h and amoxicillin 11 mg/kg q8h
- For treating Helicobacter gastritis infections (triple therapy): Given with Metronidazole 10 mg/kg PO q12h and amoxicillin 15 mg/kg q12h
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For diarrhea | 0.25 mL/kg | PO | q4-6h | — | 🌎 NA |
| For diarrhea | 0.5-1 mL/kg | PO | q12h | 3 days | 🌎 NA |
| For diarrhea in kittens and young cats | 1-2 mL | PO | 3-4 times a day | — | 🌎 NA |
| For eliminating Helicobacter gastritis infections (triple therapy) | 0.22 mL/kg | PO | q4-6h | 3 weeks | 🌎 NA |
- For diarrhea: Cats are sensitive to salicylates and probably should not receive frequent or high dosages
- For diarrhea: Using 'Pepto-Bismol Regular' or equivalent strength (17.5 mg/mL) liquid
- For diarrhea in kittens and young cats: Refrigeration may increase palatability
- For eliminating Helicobacter gastritis infections (triple therapy): Given with Metronidazole 15.4 mg/kg q8h and amoxicillin 11 mg/kg q8h
Ferrets
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For eliminating Helicobacter gastritis infections (triple therapy) | 7.5 mg/kg | PO | q8h | 3-4 weeks | 🌎 NA |
| For eliminating Helicobacter gastritis infections (triple therapy) | 17.5 mg/kg | PO | q8h | 21 days | 🌎 NA |
- For eliminating Helicobacter gastritis infections (triple therapy): Given with Metronidazole 20 mg/kg and amoxicillin 30 mg/kg
- For eliminating Helicobacter gastritis infections (triple therapy): Given with Metronidazole 20 mg/kg PO q12h, amoxicillin 20 mg/kg PO q12h, famotidine 0.5 mg/kg PO once daily, and sucralfate 25 mg/kg PO q8h
Horses
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For diarrhea in foals | 3-4 ounces per 45 kg (100 lb.) body weight | PO | q6-8h | — | 🌎 NA |
| For diarrhea in foals or adults | 1 ounce per 8 kg of body weight | PO | 3-4 times daily | — | 🌎 NA |
| For diarrhea in foals | 3-4 oz. | PO | q6-8h | — | 🌎 NA |
| For diarrhea in foals | 60 mL | PO | two to four times a day | two days | 🌎 NA |
Cattle
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For diarrhea in calves | 60 mL | PO | two to four times a day | two days | 🌎 NA |
| For diarrhea | 2-3 ounces | PO | 2-4 times a day | — | 🌎 NA |
Swine
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| For diarrhea in baby pigs | 2-5 mL | PO | two to four times a day | 2 days | 🌎 NA |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Bismuth subsalicylate is an over-the-counter gastrointestinal protectant and antidiarrheal agent. In veterinary medicine, it is primarily used to manage acute secretory diarrhea and as a component of 'triple therapy' for eradicating Helicobacter gastrointestinal infections.
Clinical Pearls:
- The parent compound is cleaved in the GI tract, releasing salicylate.
- Caution in Cats: Because cats have deficient glucuronidation pathways, they are highly sensitive to salicylates. High or repeated doses can easily cause salicylism (toxicity).
- It is radiopaque and may interfere with gastrointestinal radiologic examinations.
- Owners frequently mistake the harmless bismuth-induced black stool for melena (GI bleeding).
Mechanism of action
Bismuth subsalicylate is cleaved in the small intestine into bismuth carbonate and salicylate.
- Bismuth component: Provides physical mucosal protection, binds bacterial endotoxins, and exhibits weak antibacterial properties (which contributes to its efficacy against Helicobacter spp.).
- Salicylate component: Inhibits cyclooxygenase (COX) enzymes → decreases prostaglandin synthesis → reduces intestinal inflammation and hypersecretion, effectively mitigating clinical signs of secretory diarrhea.
Safety & warnings
Contraindications
- Pre-existing bleeding disorders
- Known hypersensitivity to salicylates
- Use with extreme caution, if at all, in cats
Adverse effects
- Constipation or fecal impaction (especially in infants or debilitated patients)
- Stool discoloration (gray-black or greenish-black)
- Salicylism / salicylate toxicity (especially in cats or at high doses)
Precautions
Species Sensitivity: Use with extreme caution in cats due to the salicylate component; cats are highly susceptible to salicylate toxicity.
Bleeding Risk: Salicylate absorption occurs; use cautiously in patients with pre-existing bleeding disorders.
Diagnostics: Bismuth is radiopaque and may interfere with GI tract radiologic examinations. It may also cause false-positive or false-negative results on various urine glucose and ketone tests.
Pregnancy/Nursing: Use with caution in pregnant and nursing animals (refer to aspirin precautions).
General: Antidiarrheal products are not a substitute for adequate fluid and electrolyte therapy when required.
Drug interactions
Bismuth can decrease the absorption of orally administered tetracyclines. Separate administration by at least 2 hours and give tetracycline first.
Concomitant administration may increase salicylate serum levels, increasing the risk of toxicity.
Monitoring
- Clinical efficacy (resolution of diarrhea)
- Fluid and electrolyte status in severe diarrhea
- Signs of salicylate toxicity (especially in cats)
Pharmacokinetics
Absorption
The amount of bismuth absorbed is negligible, while the salicylate component is rapidly and completely absorbed.
Distribution
Salicylates are highly bound to plasma proteins.
Metabolism
Salicylates are metabolized in the liver to salicylic acid.
Elimination
Salicylic acid, conjugated salicylate metabolites, and any absorbed bismuth are all excreted renally.
Overdose
Bismuth subsalicylate liquid/suspension contains approximately 8.7 mg/mL salicylate.
Note: Two tablespoonsful (30 mL) is approximately equivalent to one 325 mg aspirin tablet.
High doses can lead to salicylism (salicylate toxicity), which may manifest as gastrointestinal ulceration, bleeding, acid-base disturbances, and neurological signs. Cats are particularly vulnerable to overdose due to their deficient glucuronidation metabolism.
Available products
Formulations
- Oral suspension
- Oral paste
- Tablets
- Caplets
Veterinary
- Bismuth Subsalicylate Paste: 5% (50 mg/mL), 10% (100 mg/mL), 20% (200 mg/mL)
- Bismuth Subsalicylate Oral Suspension: 1.75% (17.5 mg/mL; 262 mg/15 mL)
- Bismuth Subsalicylate Tablets: 262 mg
Human-labeled
- Bismuth Subsalicylate Liquid/Suspension: 87 mg/5 mL, 130 mg/15 mL, 262 mg/15 mL, 524 mg/15 mL, 525 mg/15 mL
- Bismuth Subsalicylate Tablets and Caplets: 262 mg (regular & chewable)
Regulatory status
No regulatory data for: 🇺🇸 US · 🇪🇺 EU · 🇬🇧 UK · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store protected from light at room temperature; do not freeze. Incompatible with mineral acids and iron salts. Decomposes with effervescence when exposed to alkali bicarbonates.
Client information
- Shake well: Always shake the liquid product thoroughly before measuring a dose.
- Palatability: Refrigerating the liquid suspension may make it taste better to your pet. Do not mix it with milk before giving it.
- Stool Changes: This medication may change your pet's stool color to a gray-black or greenish-black. This is normal. However, if the stool becomes 'tarry' black or you see fresh blood, contact your veterinarian immediately.
- When to call the vet: If diarrhea persists for more than a day or two, or if your pet becomes lethargic or stops drinking, contact your veterinarian. Do not use this as a substitute for veterinary care if your pet is dehydrated.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.